!! File: Fourier
!! December 16, 2002 Hubert Hohn

PUBLIC PCflag,Mac5flag,M68Kflag,Unixflag,xmax,ymax
PUBLIC toolLft,toolRgt,toolBas,toolTop,toolhdr,toolHgt,toolWid  ! tool boundaries
PUBLIC winLft,winRgt,winBas,winTop,winHgt,winWid      ! window
PUBLIC workLft,workRgt,workBas,workTop,workMidx  ! work area
PUBLIC black,drkgry,drkmid,midgry,litmid,litgry,white
PUBLIC red,yellow,green,cyan,blue,magenta,pink,colorscheme
PUBLIC planeclr,gridclr,rimclr,axisclr,axislabelclr,titleclr,rightsclr
PUBLIC numberlineclr,slotdrkclr,slotlgtclr,slideclr
PUBLIC largefonts, title$, SLUmode

DECLARE DEF quitWithin,infoWithin

LET toolHgt= 560
LET toolWid= 780
LET window$= "d'Arbeloff Interactive Math Project"
LET colorscheme= 0

LET title$ = "Fourier Series Coefficients"

SUB ThisProgram
    CALL FourierCoefficients
    CLEAR
END SUB

!! ----------------------------------------------------------
!! ------ Start TB4 Mac Header and Subs ------

!LET M68KFlag = 1
!LIBRARY "MacTools*", "HHLib.trc"
!ASK PIXELS winWid,winHgt
!LET winLft= 0
!LET winTop= 0
!LET winRgt= winWid-1
!LET winBas= winHgt-1
!SET WINDOW 0,winRgt,winBas,0
!CALL Palette
!CLEAR
!
!CALL ToolPanel
!CALL ThisProgram
!
!END
!EXTERNAL
!
!MODULE Mac4Parts
!    SUB SetTextFont(font,size,style$)
!        CALL MacTextFont(font)
!        CALL MacTextSize(size)
!        CALL MacTextFace(style$)
!    END SUB
!
!    SUB StringWidth(sw$,sl)
!        DECLARE DEF MacStringWidth
!        LET sl= MacStringWidth(sw$)
!    END SUB
!
!    SUB SetLineWeight(wgt)
!        CALL MacPenSize(wgt,wgt)
!    END SUB
!
!    SUB BoxDisk(Lft,Rgt,Bas,Top)
!        CALL MacPaintOval(Lft,Rgt,Bas,Top)
!    END SUB
!END MODULE

!! --- End TB4 Mac Header and Subs ---
!!--- Start TB5 Cross-Platform header and subs ---

LIBRARY "c:\TB Gold 51a\TBLibs\TrueCtrl.trc"     ! windows
LIBRARY "c:\TB Gold 51a\TBLibs\HHLib.trc"

!LIBRARY ":TBLibs:TrueCtrl.trc"                   ! macintosh
!LIBRARY "HHLib.trc"

PUBLIC WinID
DECLARE PUBLIC OBJM_SET,OBJM_SYSINFO
LET winHgt= toolHgt
LET winWid= toolWid
DIM values(1)

CALL TC_Init

CALL Object(OBJM_SYSINFO,WinID,"MACHINE",system$,values())
IF system$="MAC" then
   LET Mac5Flag= 1
ELSE IF system$="WIN32" then
   LET PCFlag  = 1
END IF

CALL TC_SetUnitsToPixels                         ! 5.1 and up needs this
CALL TC_GetScreenSize(scrnLft,scrnRgt,scrnBas,scrnTop)
LET winLft= int((scrnRgt-scrnLft-winWid)/2)
LET winRgt= winLft+winWid-1
LET winTop= int((scrnBas-scrnTop-winHgt)/2) + 10
LET winBas= winTop+winHgt-1

CALL TC_Win_Create (WinID,"TITLE",winLft,winRgt,winBas,winTop)
LET values(1)= 2
CALL Object(OBJM_SET, WinID, "TYPE", "", values())

IF PCFlag=1 then                                 ! kill dithering
   LET  values(1)= 1
   CALL Object(OBJM_SET, WinID, "SOLID MIX", "", values())
END IF

LET  values(1)= 0
CALL TC_SetRect(WinID,winLft,winRgt,winBas,winTop)
CALL TC_Win_SetTitle(WinID,window$)
CALL TC_Show(WinID)

SET MODE "COLORSTANDARD"

ASK PIXELS winWid,winHgt                         ! must follow set mode
LET winLft= 0
LET winTop= 0
LET winRgt= winWid-1
LET winBas= winHgt-1
SET WINDOW 0,winRgt,winBas,0

CALL Palette

IF PCFlag=1 then
   LET  values(1)= 0                             ! now force solid colors
   CALL Object(OBJM_SET, WinID, "SOLID MIX", "", values())
   CALL TC_Win_RealizePalette(WinID)             ! some PCs need this

   CALL TC_Win_SetFont(WinID,"arial",9,"plain")
   CALL StringWidth("0",sw)
   IF sw>7 then LET largefonts=1 else LET largefonts=0
END IF

CALL TC_Win_Switch(WinID)

CALL ToolPanel
CALL ThisProgram

CALL SetTextFont(1,12,"bold")                    ! now shut down and clean up
LET quit$= "click the mouse or press a key to close..."
CALL PlotTextCJ(workmidx,(workbas+worktop)/2,quit$,yellow)
CALL TC_CleanUp

END
EXTERNAL

MODULE TB5Parts
    SUB StringWidth(sw$,sl)
        DECLARE PUBLIC WinID
        LET sl= StrWidth(WinID,sw$)
    END SUB

    SUB SetLineWeight(wgt)
        DECLARE PUBLIC OBJM_SET
        DECLARE PUBLIC WinID
        DIM values(1)
        LET values(1)= wgt
        CALL Object(OBJM_SET,WinID, "WIDTH", "", values())
    END SUB

    SUB SetTextFont(font,size,style$)
        DECLARE PUBLIC WinID,Mac5Flag,PCFlag,largefonts
        IF Mac5Flag=1 then
           SELECT CASE font
           CASE 4
                LET font$= "Courier"
           CASE 16
                LET font$= "Times"
           CASE else
                LET font$= "Geneva"
           END SELECT
        ELSE IF PCFlag=1 then
           IF largefonts=1 then
              IF size<12 then
                 LET size=  6
              ELSE IF size=14 then
                 LET size= 10
              ELSE IF size=18 then
                 LET size= 12
              ELSE IF size=24 then
                 LET size= 14
              ELSE IF size=12 then
                 LET size=  8
              ELSE
                 LET size= round(72/96 * size * .8)
              END IF
           ELSE
              IF size<12 then
                 LET size=  7
              ELSE IF size=14 then
                 LET size= 12
              ELSE IF size=12 then
                 LET size=  9
              ELSE IF size=18 then
                 LET size= 14
              ELSE IF size=24 then
                 LET size= 18
              ELSE
                 LET size= round(72/96 * size)
              END IF
           END IF
           SELECT CASE font
           CASE 4
                LET font$= "Courier New"
           CASE 16
                LET font$= "Times New Roman"
           CASE else
                LET font$= "Verdana"
           END SELECT
        END IF
        IF style$= "normal" then LET style$= "plain"
        CALL TC_Win_SetFont(WinID,font$,size,style$)
    END SUB

    SUB BoxDisk(Lft,Rgt,Bas,Top)
        BOX DISK Lft,Rgt,Bas,Top
    END SUB
END MODULE

!  --- End TB5 Cross-platform header and subs ---
!! ---------------------------------------------------------

!! --- Start Unix Header and Subs ---

!LET UnixFlag= 1
!ASK PIXELS winWid,winHgt
!LET winLft= 0
!LET winTop= 0
!LET winRgt= winWid-1
!LET winBas= winHgt-1
!SET WINDOW 0,winRgt,winBas,0
!CALL Palette
!
!CALL ToolPanel
!CALL ThisProgram
!
!END
!EXTERNAL
!
!MODULE UnixParts
!    SHARE CharWidth
!
!    SUB SetTextFont(font,size,style$)
!        LET font$= "-adobe-courier-"
!        IF style$= "normal" then
!           LET style$= "medium-r-normal--"
!        ELSE
!           LET style$= "bold-r-normal--"
!        END IF
!        IF size=9 then
!           LET size$= str$(10)
!        ELSE
!           LET size$= str$(size)
!        END IF
!        LET test= SetFont(font$&style$&size$&"*")
!
!        IF size=9 then
!           LET CharWidth=  6
!        ELSE IF size=12 then  ! numeric output - axis labels
!           LET CharWidth=  7
!        ELSE IF size=14 then  ! rare
!           LET CharWidth=  8
!        ELSE IF size=18 then  ! rare
!           LET CharWidth= 10
!        END IF
!    END SUB
!
!    SUB StringWidth(sw$,sl)                      ! string width in pixels
!        ! LET sl= StrWidth(sw$)
!        LET chars= len(sw$)
!        LET sl   = chars*CharWidth
!    END SUB
!
!    SUB SetLineWeight(wgt)
!        ! CALL PenSize(wgt,wgt)
!    END SUB
!
!    SUB BoxDisk(Lft,Rgt,Bas,Top)
!        CALL Fill_Circle(Lft,Rgt,Bas,Top)
!    END SUB
!END MODULE

!! ------ End of TB Unix Header and Subs ------
!! ---------------------------------------------------------


! *** Fourier Coefficients tool

SUB FourierCoefficients
    DECLARE PUBLIC black,drkgry,drkmid,midgry,litmid,litgry,white
    DECLARE PUBLIC red,yellow,green,cyan,blue,magenta,colorscheme
    DECLARE PUBLIC slideClr
    DECLARE PUBLIC workLft,workRgt,workBas,workTop,workMidx
    DECLARE PUBLIC axislabelclr,axisclr,true,false

    DECLARE DEF quitWithin, infoWithin


    ! --- help screen array ---

    DIM  info$(1:1)
    MAT READ info$
    DATA "Information on Fourier Series"


    ! ---------- Utility functions ---

    DECLARE DEF clamp,roundn,e


    ! --------- data arrays and functions ----------

    DIM Temp(0:12)                               ! temporary storage
    DIM At(0:12), Bt(0:12)                       ! dimension the target vector
    DIM As(0:12), Bs(0:12)                       ! dimension the slider vector
    DIM ParamA(0:12), ParamB(0:12)               ! parameter values from sliders

    SUB Fourier(t,k,x)
        SELECT CASE funcFlag
        CASE 1                                   ! sine
             SELECT CASE termFlag
             CASE 1                              ! all
                  LET t1= c1*(sin( 1*t))
                  LET t2= c2*(sin( 2*t))
                  LET t3= c3*(sin( 3*t))
                  LET t4= c4*(sin( 4*t))
                  LET t5= c5*(sin( 5*t))
                  LET t6= c6*(sin( 6*t))
             CASE 2                              ! odd
                  LET t1= c1*(sin( 1*t))
                  LET t2= c2*(sin( 3*t))
                  LET t3= c3*(sin( 5*t))
                  LET t4= c4*(sin( 7*t))
                  LET t5= c5*(sin( 9*t))
                  LET t6= c6*(sin(11*t))
             CASE 3                              ! even
                  LET t1= c1*(sin( 2*t))
                  LET t2= c2*(sin( 4*t))
                  LET t3= c3*(sin( 6*t))
                  LET t4= c4*(sin( 8*t))
                  LET t5= c5*(sin(10*t))
                  LET t6= c6*(sin(12*t))
             END SELECT
             LET sum= t1 + t2 + t3 + t4 + t5 + t6
        CASE 2                                   ! cosine
             SELECT CASE termFlag
             CASE 1                              ! all
                  LET t0= c0/2                   ! *(cos( 0*t))
                  LET t1= c1*(cos( 1*t))
                  LET t2= c2*(cos( 2*t))
                  LET t3= c3*(cos( 3*t))
                  LET t4= c4*(cos( 4*t))
                  LET t5= c5*(cos( 5*t))
                  LET t6= c6*(cos( 6*t))
             CASE 2                              ! odd
                  LET t0= 0                      ! c0/2
                  LET t1= c1*(cos( 1*t))
                  LET t2= c2*(cos( 3*t))
                  LET t3= c3*(cos( 5*t))
                  LET t4= c4*(cos( 7*t))
                  LET t5= c5*(cos( 9*t))
                  LET t6= c6*(cos(11*t))
             CASE 3                              ! even
                  LET t0= c0/2                   ! *(cos( 0*t))
                  LET t1= c1*(cos( 2*t))
                  LET t2= c2*(cos( 4*t))
                  LET t3= c3*(cos( 6*t))
                  LET t4= c4*(cos( 8*t))
                  LET t5= c5*(cos(10*t))
                  LET t6= c6*(cos(12*t))
             END SELECT
             LET sum= t0 + t1 + t2 + t3 + t4 + t5 + t6
        END SELECT
        LET x = k * sum
    END SUB

    SUB FourierTerm(slider,t,x)
        SELECT CASE funcFlag
        CASE 1                                   ! sine
             SELECT CASE termFlag
             CASE 1                              ! all
                  SELECT CASE slider
                  CASE 1
                       ! not needed for sine
                  CASE 2
                       LET x= c1*(sin( 1*t))
                  CASE 3
                       LET x= c2*(sin( 2*t))
                  CASE 4
                       LET x= c3*(sin( 3*t))
                  CASE 5
                       LET x= c4*(sin( 4*t))
                  CASE 6
                       LET x= c5*(sin( 5*t))
                  CASE 7
                       LET x= c6*(sin( 6*t))
                  END SELECT
             CASE 2                              ! odd
                  SELECT CASE slider
                  CASE 1
                       ! not needed for sine
                  CASE 2
                       LET x= c1*(sin( 1*t))
                  CASE 3
                       LET x= c2*(sin( 3*t))
                  CASE 4
                       LET x= c3*(sin( 5*t))
                  CASE 5
                       LET x= c4*(sin( 7*t))
                  CASE 6
                       LET x= c5*(sin( 9*t))
                  CASE 7
                       LET x= c6*(sin(11*t))
                  END SELECT
             CASE 3                              ! even
                  SELECT CASE slider
                  CASE 1
                       ! not needed for sine
                  CASE 2
                       LET x= c1*(sin( 2*t))
                  CASE 3
                       LET x= c2*(sin( 4*t))
                  CASE 4
                       LET x= c3*(sin( 6*t))
                  CASE 5
                       LET x= c4*(sin( 8*t))
                  CASE 6
                       LET x= c5*(sin(10*t))
                  CASE 7
                       LET x= c6*(sin(12*t))
                  END SELECT
             END SELECT
        CASE 2                                   ! cosine
             SELECT CASE termFlag
             CASE 1                              ! all
                  SELECT CASE slider
                  CASE 1
                       LET x= c0/2
                  CASE 2
                       LET x= c1*(cos( 1*t))
                  CASE 3
                       LET x= c2*(cos( 2*t))
                  CASE 4
                       LET x= c3*(cos( 3*t))
                  CASE 5
                       LET x= c4*(cos( 4*t))
                  CASE 6
                       LET x= c5*(cos( 5*t))
                  CASE 7
                       LET x= c6*(cos( 6*t))
                  END SELECT
             CASE 2                              ! odd
                  SELECT CASE slider
                  CASE 1
                       ! not needed for odd
                  CASE 2
                       LET x= c1*(cos( 1*t))
                  CASE 3
                       LET x= c2*(cos( 3*t))
                  CASE 4
                       LET x= c3*(cos( 5*t))
                  CASE 5
                       LET x= c4*(cos( 7*t))
                  CASE 6
                       LET x= c5*(cos( 9*t))
                  CASE 7
                       LET x= c6*(cos(11*t))
                  END SELECT
             CASE 3                              ! even
                  SELECT CASE slider
                  CASE 1
                       LET x= c0/2
                  CASE 2
                       LET x= c1*(cos( 2*t))
                  CASE 3
                       LET x= c2*(cos( 4*t))
                  CASE 4
                       LET x= c3*(cos( 6*t))
                  CASE 5
                       LET x= c4*(cos( 8*t))
                  CASE 6
                       LET x= c5*(cos(10*t))
                  CASE 7
                       LET x= c6*(cos(12*t))
                  END SELECT
             END SELECT
        END SELECT
    END SUB

    ! current target functions - best approximations of the target models
    ! DEF f1(t)= [    0  +(1/1)*sin(1*t)+(1/3)*sin(3*t)+(1/5) *sin(5*t) +(1/7) *sin(7*t) +(1/9) *sin(9*t) +(1/11) *sin(11*t)]
    ! DEF f2(t)= [    0  +(1/1)*cos(1*t)-(1/3)*cos(3*t)+(1/5) *cos(5*t) -(1/7) *cos(7*t) +(1/9) *cos(9*t) -(1/11) *cos(11*t)]
    ! DEF f3(t)= [ pi^2/8-(1/1)*cos(1*t)-(1/9)*cos(3*t)-(1/25)*cos(5*t) -(1/49)*cos(7*t) -(1/81)*cos(9*t) -(1/121)*cos(11*t)]
    ! DEF f4(t)= [    0  +(1/1)*sin(1*t)-(1/2)*sin(2*t)+(1/3) *sin(3*t) -(1/4) *sin(4*t) +(1/5) *sin(5*t) -(1/6)  *sin(6*t) ]
    ! DEF f5(t)= [    0  +(1/1)*sin(2*t)-(1/2)*sin(4*t)+(1/3) *sin(6*t) -(1/4) *sin(8*t) +(1/5) *sin(10*t)-(1/6)  *sin(12*t)]
    ! DEF f6(t)= [ pi^2/8-(1/1)*cos(2*t)-(1/9)*cos(6*t)-(1/25)*cos(10*t)-(1/49)*cos(14*t)-(1/81)*cos(18*t)-(1/121)*cos(22*t)]
    !                 0          1              3               5                7                9                 11

    ! ---- this method computes the minimum target "distance" ---

    SUB GetTargetValue(target,D1)
        MAT At = ZER                             ! zero the cosine array
        MAT Bt = ZER                             ! zero the sine array

        SELECT CASE target
        CASE 1                                   ! target A - square wave - odd sine
             ! compute terms for the target defined part of the distance value
             LET Kt = 2 * (pi/4)^2

             LET n0= 0
             LET Bt( 1),n1 = 1/1
             LET Bt( 3),n2 = 1/3
             LET Bt( 5),n3 = 1/5
             LET Bt( 7),n4 = 1/7
             LET Bt( 9),n5 = 1/9
             LET Bt(11),n6 = 1/11
        CASE 2                                   ! target B - shifted square - odd cosine
             LET Kt = 2 * (pi/4)^2

             LET At( 0),n0 =  0
             LET At( 1),n1 =  1/1
             LET At( 3),n2 = -1/3
             LET At( 5),n3 =  1/5
             LET At( 7),n4 = -1/7
             LET At( 9),n5 =  1/9
             LET At(11),n6 = -1/11
        CASE 3                                   ! target C
             LET Kt = 2/3 * (pi^2/4)^2

             LET At( 0),n0 = pi^2/4
             LET At( 1),n1 = -1/1
             LET At( 3),n2 = -1/9
             LET At( 5),n3 = -1/25
             LET At( 7),n4 = -1/49
             LET At( 9),n5 = -1/81
             LET At(11),n6 = -1/121
        CASE 4                                   ! target D
             LET Kt = 2/3 * (pi/2)^2

             LET n0= 0
             LET Bt( 1),n1 =  1/1
             LET Bt( 2),n2 = -1/2
             LET Bt( 3),n3 =  1/3
             LET Bt( 4),n4 = -1/4
             LET Bt( 5),n5 =  1/5
             LET Bt( 6),n6 = -1/6
        CASE 5                                   ! target E
             LET Kt = 2/3 * (pi/2)^2

             LET n0= 0
             LET Bt( 2),n1 =  1
             LET Bt( 4),n2 = -1/2
             LET Bt( 6),n3 =  1/3
             LET Bt( 8),n4 = -1/4
             LET Bt(10),n5 =  1/5
             LET Bt(12),n6 = -1/6
        CASE 6                                   ! target F
             LET Kt = 2/3 * (pi^2/4)^2

             LET At( 0),n0 = pi^2/4
             LET At( 2),n1 = -1/1
             LET At( 6),n2 = -1/9
             LET At(10),n3 = -1/25
             LET n4= 0
             LET n5= 0
             LET n6= 0
        END SELECT

        LET t0 = n0^2/2
        LET t1 = n1^2
        LET t2 = n2^2
        LET t3 = n3^2
        LET t4 = n4^2
        LET t5 = n5^2
        LET t6 = n6^2

        LET D1 = Kt - (t0+t1+t2+t3+t4+t5+t6)     ! target sum
    END SUB


    ! ---------- Graphing plane parameters and methods ----------

    ! --- plane 1 data ---

    DECLARE PUBLIC w1Lft,w1Rgt,w1Bas,w1Top,w1Midx,w1Midy
    DECLARE PUBLIC w1fLft,w1fRgt,w1fBas,w1fTop,w1x0,w1y0
    DECLARE PUBLIC w1xFirst, w1xSTik, w1xLTik, w1xLabel, w1xGridstep
    DECLARE PUBLIC w1yFirst, w1ySTik, w1yLTik, w1yLabel, w1yGridstep
    DECLARE PUBLIC w1wWid,w1wHgt,w1fWid,w1fHgt
    DECLARE PUBLIC w1fxRatio,w1fyRatio,w1wxRatio,w1wyRatio,w1Aspect
    DECLARE PUBLIC w1xPiFlag, w1xMult, w1yPiFlag, w1yMult

    LET w1Flag   = 0
    LET w1xPiFlag= 1
    LET w1yPiFlag= 0
    LET w1xMult  = pi
    LET w1yMult  = 1

    LET w1Lft = worklft + 55                     ! pixel bounds
    LET w1Rgt = w1Lft + 314                      ! 6.28
    LET w1Top = worktop + 50
    LET w1Bas = w1Top + 300                      ! 6.00

    LET w1fLft= -1                               ! function bounds
    LET w1fRgt=  1
    LET w1fBas= -3
    LET w1fTop=  3

    LET w1xAx$= "t"                              ! axis labels
    LET w1yAx$= "x"

    LET w1xGridstep= 0.5                         ! horizontal grid intervals
    LET w1yGridstep= 1.0                         ! vertical grid intervals

    LET w1xSTik  = 0.5                           ! horizontal axis Tik marks
    LET w1xLTik  = 1
    LET w1xLabel = 1
    LET w1xFirst = w1fLft

    LET w1ySTik  = 0.5                           ! vertical axis Tik marks
    LET w1yLTik  = 1
    LET w1yLabel = 1
    LET w1yFirst = w1fBas


    ! --- Plane 1 methods ---

    DECLARE DEF w1Fncx,w1Fncy,w1Wndx,w1Wndy      ! window/function transforms
    DECLARE DEF w1wWithin, w1Within

    CALL w1Variables

    SUB w1Init
        CALL w1DrawPlane(1,1,1)                  ! x axis, y axis, zeroaxes
        CALL SetTextFont(1,12,"bold")
        CALL PlotTextLJ(w1Rgt+8,w1y0+3,w1xAx$,axislabelClr)     ! axis labels
        CALL PlotTextCJ(w1x0,w1Top-10,w1yAx$,axislabelClr)
        CALL w1KeepGridLayer
    END SUB

    ! ---------- Slider parameters and methods ----------

    ! ----------- horizontal sliders ------------

    LET slideWidth= 200
    LET hstep     =  64                          ! vertical slider spacing
    LET slideClr  = white

    ! --- horizontal slider 1 ---

    DECLARE DEF h0Within                         ! window/function transforms

    DECLARE PUBLIC h0axis,h0wLft,h0wRgt,h0wBas,h0wTop,h0fLft,h0fRgt
    DECLARE PUBLIC h0name$,h0form$,h0clr,h0First,h0STik,h0LTik,h0Label
    DECLARE PUBLIC h0PiAxis,h0Mult,h0fMin,h0fMax,h0wWid,h0fWid

    LET h0PiAxis= 0
    LET h0Mult  = 1

    LET h0Clr   = slideClr
    LET h0name$ = ""
    LET h0form$ = "-%.###"
    LET h0Places= 3

    LET h0axis = w1Top
    LET h0wLft = w1Rgt+120
    LET h0wRgt = h0wLft+slideWidth

    LET h0fLft = -4                              ! h0flft
    LET h0fRgt =  4                              ! h0frgt

    LET h0STik =  .5                             ! short tick marks
    LET h0LTik =  1                              ! long tick marks
    LET h0Label=  4                              ! labels
    LET h0First= -4                              ! first tick mark
    LET h0Click=  1

    LET h0xPix = (h0fRgt-h0fLft)/slideWidth
    DECLARE DEF h0LstpWithin,h0RstpWithin

    CALL h0SliderVariables


    ! --- Slider 2 ---

    DECLARE DEF h1Within                         ! window/function transforms

    DECLARE PUBLIC h1axis,h1wLft,h1wRgt,h1wBas,h1wTop,h1fLft,h1fRgt
    DECLARE PUBLIC h1name$,h1form$,h1clr,h1First,h1STik,h1LTik,h1Label
    DECLARE PUBLIC h1PiAxis,h1Mult,h1fMin,h1fMax

    LET h1PiAxis= 0
    LET h1Mult  = 1

    LET h1Clr   = slideClr
    LET h1name$ = ""
    LET h1form$ = "-%.###"
    LET h1Places= 3

    LET h1axis = h0axis+hstep
    LET h1wLft = h0wLft
    LET h1wRgt = h1wLft+slidewidth

    LET h1fLft = -2
    LET h1fRgt =  2

    LET h1STik =  0.2
    LET h1LTik =  1
    LET h1Label=  2
    LET h1First= -2
    LET h1Click=  0.2

    LET h1xPix = (h1fRgt-h1fLft)/slideWidth
    DECLARE DEF h1LstpWithin,h1RstpWithin


    CALL h1SliderVariables


    ! --- slider 3 ---

    DECLARE DEF h2Within                         ! window/function transforms

    DECLARE PUBLIC h2axis,h2wLft,h2wRgt,h2wBas,h2wTop,h2fLft,h2fRgt
    DECLARE PUBLIC h2name$,h2form$,h2clr,h2First,h2STik,h2LTik,h2Label
    DECLARE PUBLIC h2PiAxis,h2Mult,h2fMin,h2fMax

    LET h2PiAxis= 0
    LET h2Mult  = 1

    LET h2Clr   = slideClr
    LET h2name$ = ""
    LET h2form$ = "-%.###"
    LET h2Places= 3

    LET h2axis = h1axis+hstep
    LET h2wLft = h0wLft
    LET h2wRgt = h2wLft+slideWidth

    LET h2fLft = -1
    LET h2fRgt =  1

    LET h2STik =  0.1
    LET h2LTik =  0.5
    LET h2Label=  1
    LET h2First= -1
    LET h2Click=  0.1

    LET h2xPix = (h2fRgt-h2fLft)/slideWidth
    DECLARE DEF h2LstpWithin,h2RstpWithin

    CALL h2SliderVariables


    ! --- slider 4 ---

    DECLARE DEF h3Within                         ! window/function transforms

    DECLARE PUBLIC h3axis,h3wLft,h3wRgt,h3wBas,h3wTop,h3fLft,h3fRgt
    DECLARE PUBLIC h3name$,h3form$,h3clr,h3First,h3STik,h3LTik,h3Label
    DECLARE PUBLIC h3PiAxis,h3Mult,h3fMin,h3fMax

    LET h3PiAxis= 0
    LET h3Mult  = 1

    LET h3Clr   = slideClr
    LET h3name$ = ""
    LET h3form$ = "-%.###"
    LET h3Places= 3

    LET h3axis = h2axis+hstep
    LET h3wLft = h0wLft
    LET h3wRgt = h3wLft+slideWidth

    LET h3fLft = -0.5
    LET h3fRgt =  0.5

    LET h3STik =  0.1
    LET h3LTik =  0.5
    LET h3Label=  0.5
    LET h3First= -0.5
    LET h3Click=  0.1

    LET h3xPix = (h3fRgt-h3fLft)/slideWidth
    DECLARE DEF h3LstpWithin,h3RstpWithin

    CALL h3SliderVariables


    ! --- slider 5 ---

    DECLARE DEF h4Within                         ! window/function transforms

    DECLARE PUBLIC h4axis,h4wLft,h4wRgt,h4wBas,h4wTop,h4fLft,h4fRgt
    DECLARE PUBLIC h4name$,h4form$,h4clr,h4First,h4STik,h4LTik,h4Label
    DECLARE PUBLIC h4PiAxis,h4Mult,h4fMin,h4fMax

    LET h4PiAxis= 0
    LET h4Mult  = 1

    LET h4Clr   = slideClr
    LET h4name$ = ""
    LET h4form$ = "-%.###"
    LET h4Places= 3

    LET h4axis = h3axis+hstep
    LET h4wLft = h0wLft
    LET h4wRgt = h4wLft+SlideWidth

    LET h4fLft = -0.5
    LET h4fRgt =  0.5

    LET h4STik =  0.1
    LET h4LTik =  0.5
    LET h4Label=  0.5
    LET h4First= -0.5
    LET h4Click=  0.1

    LET h4xPix = (h4fRgt-h4fLft)/slideWidth
    DECLARE DEF h4LstpWithin,h4RstpWithin

    CALL h4SliderVariables


    ! --- slider 6 ---

    DECLARE DEF h5Within                         ! window/function transforms

    DECLARE PUBLIC h5axis,h5wLft,h5wRgt,h5wBas,h5wTop,h5fLft,h5fRgt
    DECLARE PUBLIC h5name$,h5form$,h5clr,h5First,h5STik,h5LTik,h5Label
    DECLARE PUBLIC h5PiAxis,h5Mult,h5fMin,h5fMax

    LET h5PiAxis= 0
    LET h5Mult  = 1

    LET h5Clr   = slideClr
    LET h5name$ = ""
    LET h5form$ = "-%.###"
    LET h5Places= 3

    LET h5axis = h4axis+hstep
    LET h5wLft = h0wLft
    LET h5wRgt = h5wLft+SlideWidth

    LET h5fLft = -0.25
    LET h5fRgt =  0.25

    LET h5STik =  0.05
    LET h5LTik =  0.25
    LET h5Label=  0.25
    LET h5First= -0.25
    LET h5Click=  0.05

    LET h5xPix = (h5fRgt-h5fLft)/slideWidth
    DECLARE DEF h5LstpWithin,h5RstpWithin

    CALL h5SliderVariables


    ! --- slider 7 ---

    DECLARE DEF h6Within                         ! window/function transforms

    DECLARE PUBLIC h6axis,h6wLft,h6wRgt,h6wBas,h6wTop,h6fLft,h6fRgt
    DECLARE PUBLIC h6name$,h6form$,h6clr,h6First,h6STik,h6LTik,h6Label
    DECLARE PUBLIC h6PiAxis,h6Mult,h6fMin,h6fMax

    LET h6PiAxis= 0
    LET h6Mult  = 1

    LET h6Clr   = slideClr
    LET h6name$ = ""
    LET h6form$ = "-%.###"
    LET h6Places= 3

    LET h6axis = h5axis+hstep
    LET h6wLft = h0wLft
    LET h6wRgt = h6wLft+SlideWidth

    LET h6fLft = -0.25
    LET h6fRgt =  0.25

    LET h6STik =  0.05
    LET h6LTik =  0.25
    LET h6Label=  0.25
    LET h6First= -0.25
    LET h6Click=  0.05

    LET h6xPix = (h6fRgt-h6fLft)/slideWidth
    DECLARE DEF h6LstpWithin,h6RstpWithin

    CALL h6SliderVariables


    ! ------------- Text Boxes -------------
    ! ----- t1 - distance value output -----

    LET dbasln= workTop+22
    LET dlft  = w1Lft+30
    LET drgt  = w1Rgt-20
    LET dtop  = dbasln-17
    LET dbas  = dbasln+3

    SUB ClearDistance
        BOX CLEAR dlft,drgt,dbas,dtop
    END SUB

    SUB SetDistance
        IF distFlag=1 then
           CALL SetTextFont(1,18,"bold")
           LET n$= using$("-%.#####",D)
           CALL ClearDistance
           FOR i= 1 to 8                         ! monospace for readability
               LET ch$= n$(i:i)
               LET tx = dlft + (i-1)*30 + 5
               CALL PlotTextCJ(tx,dbasln,ch$,white)
           NEXT i
        END IF
    END SUB

    SUB ResetDistance
        CALL ClearDistance
        IF target>-1 and distFlag=1 then
           CALL GetDistance(target,D)
           CALL SetDistance
        END IF
    END SUB

    ! ----- t2 - Fourier series display -----

    LET fstop= workBas-23
    LET fsbas= fstop+20
    LET fslft= worklft
    LET fsrgt= workrgt

    SUB SetFunction
        CALL ClearFunction

        IF formFlag=1 then
           CALL SetTextFont(1,12,"bold")

           LET txt$ = "x(t) = "
           SELECT CASE funcFlag
           CASE 1
                SELECT CASE termFlag
                CASE 1
                     LET txt1$= "b_[1]sin(t) + b_[2]sin(2t) + b_[3]sin(3t) + b_[4]sin(4t) + b_[5]sin(5t) + b_[6]sin(6t) + ..."
                CASE 2
                     LET txt1$= "b_[1]sin(t) + b_[3]sin(3t) + b_[5]sin(5t) + b_[7]sin(7t) + b_[9]sin(9t) + b_[11]sin(11t) + ..."
                CASE 3
                     LET txt1$= "b_[2]sin(2t) + b_[4]sin(4t) + b_[6]sin(6t) + b_[8]sin(8t) + b_[10]sin(10t) + b_[12]sin(12t) + ..."
                END SELECT
           CASE 2
                SELECT CASE termFlag
                CASE 1
                     LET txt1$= "a_[0](0.5) + a_[1]cos(t) + a_[2]cos(2t) + a_[3]cos(3t) + a_[4]cos(4t) + a_[5]cos(5t) + a_[6]cos(6t) + ..."
                CASE 2
                     LET txt1$= "a_[1]cos(t) + a_[3]cos(3t) + a_[5]cos(5t) + a_[7]cos(7t) + a_[9]cos(9t) + a_[11]cos(11t) + ..."
                CASE 3
                     LET txt1$= "a_[0](0.5) + a_[2]cos(2t) + a_[4]cos(4t) + a_[6]cos(6t) + a_[8]cos(8t) + a_[10]cos(10t) + a_[12]cos(12t) + ..."
                END SELECT
           END SELECT

           CALL SuperSubScriptLJ(w1Lft,fsbas-8,txt$&txt1$,white)
        END IF
    END SUB

    SUB ClearFunction
        BOX CLEAR fslft,fsrgt,fsbas,fstop
    END SUB


    ! -------- Radio Boxes --------
    ! ---- r1 - Series ---

    DECLARE PUBLIC r1cnt,r1stp,r1siz
    DECLARE PUBLIC r1lft,r1rgt,r1bas,r1top,r1Name$,r1NameClr
    DECLARE PUBLIC r1NameList$(),r1ColorList()

    MAT redim r1NameList$(1:2)
    MAT READ r1NameList$
    DATA "Sine Series", "Cosine Series"

    MAT redim r1ColorList(1:2)
    MAT READ r1ColorList
    DATA 5,5

    LET r1cnt    = 2
    LET r1Lft    = w1Rgt - 120
    LET r1Top    = w1Bas +  35
    LET r1Name$  = ""
    LET r1NameClr= 5

    DECLARE DEF r1Within
    CALL r1SetVars

    ! ---- r2 - Terms ---

    DECLARE PUBLIC r2cnt,r2stp,r2siz
    DECLARE PUBLIC r2lft,r2rgt,r2bas,r2top,r2Name$,r2NameClr
    DECLARE PUBLIC r2NameList$(),r2ColorList()

    MAT redim r2NameList$(1:3)
    MAT READ r2NameList$
    DATA "All terms", "Odd terms", "Even terms"

    MAT redim r2ColorList(1:3)
    MAT READ r2ColorList
    DATA 5,5,5

    LET r2cnt    = 3
    LET r2Lft    = r1Lft
    LET r2Top    = r1Top + 3*r2stp
    LET r2Name$  = ""
    LET r2NameClr= 5

    DECLARE DEF r2Within
    CALL r2SetVars

    ! --- r3 - Models ---

    DECLARE PUBLIC r3cnt,r3stp,r3siz
    DECLARE PUBLIC r3lft,r3rgt,r3bas,r3top,r3Name$,r3NameClr
    DECLARE PUBLIC r3NameList$(),r3ColorList()

    MAT redim r3NameList$(1:6)
    MAT READ r3NameList$
    DATA "A", "B", "C", "D", "E", "F"

    MAT redim r3ColorList(1:6)
    MAT READ r3ColorList
    DATA 5,5,5,5,5,5

    LET r3cnt    = 6
    LET r3Lft    = r1Lft - 65
    LET r3Top    = r1Top
    LET r3Name$  = ""
    LET r3NameClr= 5

    DECLARE DEF r3Within
    CALL r3SetVars


    ! --- checkbox - series formula ---

    DECLARE PUBLIC cb1Lft,cb1Rgt,cb1Bas,cb1Top,cb1Txt$,cb1Clr,cb1State
    DECLARE DEF cb1Within

    LET cb1Lft = w1Lft
    LET cb1Bas = r2Top + r2siz
    LET cb1Txt$= "Formula"
    LET cb1Clr = litgry

    CALL cb1Variables


    ! --- checkbox - distance value ---

    DECLARE PUBLIC cb2Lft,cb2Rgt,cb2Bas,cb2Top,cb2Txt$,cb2Clr,cb2State
    DECLARE DEF cb2Within

    LET cb2Lft = cb1Lft
    LET cb2Bas = cb1Bas + 18
    LET cb2Txt$= "Distance"
    LET cb2Clr = litgry

    CALL cb2Variables

    SUB distButton(target)
        CALL SetTextFont(1,12,"bold")

        IF target>-1 then
           CALL cb2Init

           IF chkFlag=1 then                     ! SLU
              CALL DrawButton(cklft,ckrgt,ckbas,cktop,5,"Check")
           END IF
        ELSE
           BOX CLEAR cb2Lft,cb2Lft+100,cb2Bas,cb2Top
           IF chkFlag=1 then BOX CLEAR cklft,ckrgt,ckbas,cktop
        END IF
    END SUB


    ! ----- Buttons -----

    SUB Buttons
        CALL SetTextFont(1,12,"bold")
        LET bhgt= 18

        LET clft= w1Lft
        LET crgt= clft+75
        LET ctop= w1bas+35
        LET cbas= ctop+bhgt
        CALL DrawButton(clft,crgt,cbas,ctop,5,"Clear")

        LET zlft= cLft
        LET zrgt= cRgt
        LET ztop= cBas + 2
        LET zbas= ztop+bhgt
        CALL DrawButton(zlft,zrgt,zbas,ztop,5,"Reset")
    END SUB


    ! ----- SLU only - check buttons for setting exact values ---

    DIM targetValues(1:6,0:6)
    MAT READ targetValues

    DATA        0, 1, 0.333333, 0.200000, 0.142857, 0.111111, 0.090909
    DATA        0, 1,-0.333333, 0.200000,-0.142857, 0.111111,-0.090909
    DATA 2.467401,-1, 0       ,-0.111111, 0       ,-0.040000, 0      !-0.020408,-0.012346,-0.008264
    DATA        0, 1,-0.500000, 0.333333,-0.250000, 0.200000,-0.166667
    !DATA        0, 0, 1       , 0       ,-0.500000, 0,        0.333333    !, 0    !-0.250000, 0.200000,-0.166667
    DATA        0, 1,-0.500000, 0.333333,-0.250000, 0.200000, -0.166667
    DATA 2.467401,-1, 0       ,-0.111111, 0       ,-0.040000, 0      !-0.020408,0,-0.012346,0,-0.008264

    LET cklft = h0wLft-85
    LET ckrgt = cklft+50
    LET cktop = workbas-55
    LET ckbas = cktop+18

    LET hboxlft= cklft+19
    LET hboxrgt= hboxlft+12

    SUB CheckButtonsDraw
        IF funcFlag=2 and termFlag<>2 then
           CALL DrawButton(hboxlft,hboxrgt,h0wBas-2,h0wBas-14,0,"")
        END IF
        CALL DrawButton(hboxlft,hboxrgt,h1wBas-2,h1wBas-14,0,"")
        CALL DrawButton(hboxlft,hboxrgt,h2wBas-2,h2wBas-14,0,"")
        CALL DrawButton(hboxlft,hboxrgt,h3wBas-2,h3wBas-14,0,"")
        CALL DrawButton(hboxlft,hboxrgt,h4wBas-2,h4wBas-14,0,"")
        CALL DrawButton(hboxlft,hboxrgt,h5wBas-2,h5wBas-14,0,"")
        CALL DrawButton(hboxlft,hboxrgt,h6wBas-2,h6wBas-14,0,"")
    END SUB

    SUB CheckButtonsClear                        ! SLU
        BOX CLEAR hboxlft,hboxrgt,h6wbas+15,h0wtop-5
    END SUB

    ! --- end of design and layout ---


    ! --- set default parameters ---

    LET funcFlag=  1
    LET termFlag=  1
    LET target  = -1
    LET r1num   =  1
    LET r2num   =  1
    LET r3num   =  0

    LET distFlag=  0
    LET formFlag=  0
    LET chkFlag =  0                             ! SLU
    LET k       =  1

    LET c0,c1,c2,c3,c4,c5,c6,c7= 0


    ! --- Draw the screen ---

    CALL InitScreen

    SUB InitScreen
        BOX CLEAR worklft,workrgt,workbas,worktop

        CALL w1Init
        CALL DrawModel(target)

        CALL Buttons
        CALL cb1Init

        CALL r1DrawCheckBoxes
        CALL r1SetCheckBox(r1num)
        CALL r2DrawCheckBoxes
        CALL r2SetCheckBox(r2num)
        CALL r3DrawCheckBoxes
        IF target>0 then CALL r3SetCheckBox(r3num)

        CALL SetFunction
        CALL DrawSliders(0)
        CALL ReDraw
    END SUB


    ! ----------------- Event manager -----------------

    DO
       CALL MouseDown(mx,my,ms)
       LET oldx= -99999

       IF h0Flag=true and h0Within(mx,my)=true then
          IF my<h0axis then
             CALL h0MouseClick
          ELSE
             CALL h0MouseDrag
          END IF
       ELSE IF h1Within(mx,my)=true then
          IF my<h1axis then
             CALL h1MouseClick
          ELSE
             CALL h1MouseDrag
          END IF
       ELSE IF h2Within(mx,my)=true then
          IF my<h2axis then
             CALL h2MouseClick
          ELSE
             CALL h2MouseDrag
          END IF
       ELSE IF h3Within(mx,my)=true then
          IF my<h3axis then
             CALL h3MouseClick
          ELSE
             CALL h3MouseDrag
          END IF
       ELSE IF h4Within(mx,my)=true then
          IF my<h4axis then
             CALL h4MouseClick
          ELSE
             CALL h4MouseDrag
          END IF
       ELSE IF h5Within(mx,my)=true then
          IF my<h5axis then
             CALL h5MouseClick
          ELSE
             CALL h5MouseDrag
          END IF
       ELSE IF h6Within(mx,my)=true then
          IF my<h6axis then
             CALL h6MouseClick
          ELSE
             CALL h6MouseDrag
          END IF

          ! slider step buttons

       ELSE IF h0LstpWithin(mx,my)=true then
          CALL h0LstpButtonUp(ms)
          CALL h0LeftStep(c0,h0xPix)
          CALL ClickAction(c0,oldc0)
       ELSE IF h0RstpWithin(mx,my)=true then
          CALL h0RstpButtonUp(ms)
          CALL h0RightStep(c0,h0xPix)
          CALL ClickAction(c0,oldc0)
       ELSE IF h1LstpWithin(mx,my)=true then
          CALL h1LstpButtonUp(ms)
          CALL h1LeftStep(c1,h1xPix)
          CALL ClickAction(c1,oldc1)
       ELSE IF h1RstpWithin(mx,my)=true then
          CALL h1RstpButtonUp(ms)
          CALL h1RightStep(c1,h1xPix)
          CALL ClickAction(c1,oldc1)
       ELSE IF h2LstpWithin(mx,my)=true then
          CALL h2LstpButtonUp(ms)
          CALL h2LeftStep(c2,h2xPix)
          CALL ClickAction(c2,oldc2)
       ELSE IF h2RstpWithin(mx,my)=true then
          CALL h2RstpButtonUp(ms)
          CALL h2RightStep(c2,h2xPix)
          CALL ClickAction(c2,oldc2)
       ELSE IF h3LstpWithin(mx,my)=true then
          CALL h3LstpButtonUp(ms)
          CALL h3LeftStep(c3,h3xPix)
          CALL ClickAction(c3,oldc3)
       ELSE IF h3RstpWithin(mx,my)=true then
          CALL h3RstpButtonUp(ms)
          CALL h3RightStep(c3,h3xPix)
          CALL ClickAction(c3,oldc3)
       ELSE IF h4LstpWithin(mx,my)=true then
          CALL h4LstpButtonUp(ms)
          CALL h4LeftStep(c4,h4xPix)
          CALL ClickAction(c4,oldc4)
       ELSE IF h4RstpWithin(mx,my)=true then
          CALL h4RstpButtonUp(ms)
          CALL h4RightStep(c4,h4xPix)
          CALL ClickAction(c4,oldc4)
       ELSE IF h5LstpWithin(mx,my)=true then
          CALL h5LstpButtonUp(ms)
          CALL h5LeftStep(c5,h5xPix)
          CALL ClickAction(c5,oldc5)
       ELSE IF h5RstpWithin(mx,my)=true then
          CALL h5RstpButtonUp(ms)
          CALL h5RightStep(c5,h5xPix)
          CALL ClickAction(c5,oldc5)
       ELSE IF h6LstpWithin(mx,my)=true then
          CALL h6LstpButtonUp(ms)
          CALL h6LeftStep(c6,h6xPix)
          CALL ClickAction(c6,oldc6)
       ELSE IF h6RstpWithin(mx,my)=true then
          CALL h6RstpButtonUp(ms)
          CALL h6RightStep(c6,h6xPix)
          CALL ClickAction(c6,oldc6)

          ! these items put exact values in the sliders - not used at MIT

       ELSE IF chkFlag=true and mx>ckLft and mx<ckRgt and my>ckTop and my<ckBas then     ! check values
          ! SLU - not used in MIT version
          CALL MouseButtonUp(ckLft,ckRgt,ckBas,ckTop,ms)

          IF chkFlag=1 then
             SELECT CASE target
             CASE 1
                  ! A - sine, odd
                  LET funcFlag= 1
                  LET termFlag= 2
             CASE 2
                  ! B - cosine, odd
                  LET funcFlag= 2
                  LET termFlag= 2
             CASE 3
                  ! C - cosine, odd
                  LET funcFlag= 2
                  LET termFlag= 1
             CASE 4
                  ! D - sine, all
                  LET funcFlag= 1
                  LET termFlag= 1
             CASE 5
                  ! E - sine, all ! should be even? bug on even? alternating
                  LET funcFlag= 1
                  LET termFlag= 3
             CASE 6
                  ! F - cosine, even
                  LET funcFlag= 2
                  LET termFlag= 3
             END SELECT
             LET r1num= funcFlag
             LET r2num= termFlag
             CALL r1SetCheckBox(r1num)
             CALL r2SetCheckBox(r2num)

             CALL DrawSliders(0)
             CALL SetFunction
             CALL ResetDistance
             CALL CheckButtonsDraw
          END IF
       ELSE IF chkFlag=true and mx>hboxlft and mx<hboxrgt and my>h0wtop and my<h6wbas then
          ! SLU - not used in MIT version
          IF chkFlag=1 then
             IF my>h0wTop and my<h0wBas then
                CALL MouseUp(mx,my,ms)
                LET c0= targetValues(target,0)
                CALL h0Mark(c0)
                CALL ReDraw
             ELSE IF my>h1wTop and my<h1wBas then
                CALL MouseUp(mx,my,ms)
                LET c1= targetValues(target,1)
                CALL h1Mark(c1)
                CALL ReDraw
             ELSE IF my>h2wTop and my<h2wBas then
                CALL MouseUp(mx,my,ms)
                LET c2= targetValues(target,2)
                CALL h2Mark(c2)
                CALL ReDraw
             ELSE IF my>h3wTop and my<h3wBas then
                CALL MouseUp(mx,my,ms)
                LET c3= targetValues(target,3)
                CALL h3Mark(c3)
                CALL ReDraw
             ELSE IF my>h4wTop and my<h4wBas then
                CALL MouseUp(mx,my,ms)
                LET c4= targetValues(target,4)
                CALL h4Mark(c4)
                CALL ReDraw
             ELSE IF my>h5wTop and my<h5wBas then
                CALL MouseUp(mx,my,ms)
                LET c5= targetValues(target,5)
                CALL h5Mark(c5)
                CALL ReDraw
             ELSE IF my>h6wTop and my<h6wBas then
                CALL MouseUp(mx,my,ms)
                LET c6= targetValues(target,6)
                CALL h6Mark(c6)
                CALL ReDraw
             ELSE
                CALL MouseUp(mx,my,ms)
             END IF
          ELSE
             CALL MouseUp(mx,my,ms)
          END IF

          ! end of SLU code

          ! radio buttons

       ELSE IF r1Within(mx,my)=true then         ! series
          CALL MouseUp(mx,my,ms)
          CALL StoreSliderVars
          LET r1num   = int((my-r1Top)/r1Stp) + 1
          LET funcFlag= r1num
          CALL r1SetCheckBox(r1num)

          CALL ZeroSliders
          CALL CheckButtonsClear                 ! SLU version
          CALL SetFunction
          CALL DrawSliders(0)
          CALL ReDraw
       ELSE IF r2Within(mx,my)=true then         ! terms
          CALL MouseUp(mx,my,ms)
          CALL StoreSliderVars
          LET oldr2   = r2num
          LET r2num   = int((my-r2Top)/r2Stp) + 1
          LET termFlag= r2num
          CALL r2SetCheckBox(r2num)

          IF oldr2=2 or r2num=2 then             ! odd
             IF r1num=1 then                     ! sine
                CALL KeepBOdd
             ELSE                                ! cosine
                CALL KeepAOdd
             END IF
          ELSE IF oldr2=3 or r2num=3 then        ! even
             IF r1num=1 then                     ! sine
                CALL KeepBEven
             ELSE                                ! cosine
                CALL KeepAEven
             END IF
          END IF

          CALL CheckButtonsClear                 ! SLU version
          CALL SetFunction
          CALL DrawSliders(0)
          CALL ReDraw
       ELSE IF r3Within(mx,my)=true then         ! target
          CALL MouseUp(mx,my,ms)
          LET r3num = int((my-r3Top)/r3Stp) + 1
          LET target= r3num
          CALL distButton(target)
          CALL r3SetCheckBox(r3num)
          CALL DrawModel(target)
          CALL CheckButtonsClear                 ! SLU version
          CALL ReDraw

          ! single checkboxes

       ELSE IF cb1Within(mx,my)=true then
          CALL cb1MouseUp(ms)
          LET formFlag= cb1State
          CALL SetFunction
       ELSE IF cb2Within(mx,my)=true then
          CALL cb2MouseUp(ms)
          LET distFlag= cb2State
          CALL ResetDistance

          ! buttons

       ELSE IF mx>cLft and mx<cRgt and my>cTop and my<cBas then      ! clear model
          CALL MouseButtonUp(cLft,cRgt,cBas,cTop,ms)
          LET target= -1
          CALL r3SetCheckBox(0)
          CALL DrawModel(target)
          IF chkflag=1 then CALL ClearDistance
          CALL distButton(target)
          CALL CheckButtonsClear
          CALL DrawGraph(1,1)
       ELSE IF mx>zLft and mx<zRgt and my>zTop and my<zBas then      ! reset: zero sliders
          CALL MouseButtonUp(zLft,zRgt,zBas,zTop,ms)
          CALL ZeroSliders
          CALL ReDraw

       ELSE IF infoWithin(mx,my,ms)=true then
          CALL infoButtonUp(ms)
          CALL InfoPage(Info$)
          CALL InitScreen
       ELSE IF quitWithin(mx,my,ms)=true then
          CALL quitButtonUp(ms)
          EXIT SUB
       ELSE
          CALL MouseUp(mx,my,ms)
       END IF
    LOOP

    ! --- Mouse Event Methods ---

    SUB ClickAction(n,oldn)
        CALL ReDraw
        LET oldn= n
    END SUB
    SUB DragAction(n,oldn,eq)
        IF n<>oldn then
           CALL DrawTerm(5,eq)
           CALL DrawGraph(5,0)
           CALL ResetDistance
           LET oldn= n
        END IF
    END SUB

    ! ---

    SUB h0MouseClick
        CALL h0GetClickVal(ms,h0Click,c0)
        CALL ClickAction(c0,oldc0)
    END SUB
    SUB h0MouseDrag
        DO
           CALL h0GetDragVal(ms,h0Places,c0)
           CALL DragAction(c0,oldc0,1)
        LOOP until ms=3
        CALL DrawGraph(1,1)
    END SUB

    ! ---

    SUB h1MouseClick
        CALL h1GetClickVal(ms,h1Click,c1)
        CALL ClickAction(c1,oldc1)
    END SUB
    SUB h1MouseDrag
        DO
           CALL h1GetDragVal(ms,h1Places,c1)
           CALL DragAction(c1,oldc1,2)
        LOOP until ms=3
        CALL DrawGraph(1,1)
    END SUB

    ! ---

    SUB h2MouseClick
        CALL h2GetClickVal(ms,h2Click,c2)
        CALL ClickAction(c2,oldc2)
    END SUB
    SUB h2MouseDrag
        DO
           CALL h2GetDragVal(ms,h2Places,c2)
           CALL DragAction(c2,oldc2,3)
        LOOP until ms=3
        CALL DrawGraph(1,1)
    END SUB

    ! ---

    SUB h3MouseClick
        CALL h3GetClickVal(ms,h3Click,c3)
        CALL ClickAction(c3,oldc3)
    END SUB
    SUB h3MouseDrag
        DO
           CALL h3GetDragVal(ms,h3Places,c3)
           CALL DragAction(c3,oldc3,4)
        LOOP until ms=3
        CALL DrawGraph(1,1)
    END SUB

    ! ---

    SUB h4MouseClick
        CALL h4GetClickVal(ms,h4Click,c4)
        CALL ClickAction(c4,oldc4)
    END SUB
    SUB h4MouseDrag
        DO
           CALL h4GetDragVal(ms,h4Places,c4)
           CALL DragAction(c4,oldc4,5)
        LOOP until ms=3
        CALL DrawGraph(1,1)
    END SUB

    ! ---

    SUB h5MouseClick
        CALL h5GetClickVal(ms,h5Click,c5)
        CALL ClickAction(c5,oldc5)
    END SUB
    SUB h5MouseDrag
        DO
           CALL h5GetDragVal(ms,h5Places,c5)
           CALL DragAction(c5,oldc5,6)
        LOOP until ms=3
        CALL DrawGraph(1,1)
    END SUB

    ! ---

    SUB h6MouseClick
        CALL h6GetClickVal(ms,h6Click,c6)
        CALL ClickAction(c6,oldc6)
    END SUB
    SUB h6MouseDrag
        DO
           CALL h6GetDragVal(ms,h6Places,c6)
           CALL DragAction(c6,oldc6,7)
        LOOP until ms=3
        CALL DrawGraph(1,1)
    END SUB


    ! --------- slider management methods ----------

    SUB ZeroSliders
        LET k= 1
        LET c0,c1,c2,c3,c4,c5,c6,c7= 0
        MAT ParamA= ZER
        MAT ParamB= ZER

        IF funcFlag=2 and termFlag<>2 then CALL h0Mark(c0)
        CALL h1Mark(c1)
        CALL h2Mark(c2)
        CALL h3Mark(c3)
        CALL h4Mark(c4)
        CALL h5Mark(c5)
        CALL h6Mark(c6)
    END SUB

    SUB KeepAOdd                                 ! cosine
        FOR i= 0 to 12 step 2
            LET ParamA(i)= 0
        NEXT i
    END SUB
    SUB KeepAEven                                ! cosine
        FOR i= 1 to 11 step 2
            LET ParamA(i)= 0
        NEXT i
    END SUB
    SUB KeepBOdd                                 ! sine
        FOR i= 0 to 12 step 2
            LET ParamB(i)= 0
        NEXT i
    END SUB
    SUB KeepBEven                                ! sine
        FOR i= 1 to 11 step 2
            LET ParamB(i)= 0
        NEXT i
    END SUB


    SUB SliderValues
        SELECT CASE termFlag
        CASE 1                                   ! all
             LET Temp( 1) = c1
             LET Temp( 2) = c2
             LET Temp( 3) = c3
             LET Temp( 4) = c4
             LET Temp( 5) = c5
             LET Temp( 6) = c6
             LET Temp( 7) = c7
        CASE 2                                   ! odd
             LET Temp( 1) = c1
             LET Temp( 3) = c2
             LET Temp( 5) = c3
             LET Temp( 7) = c4
             LET Temp( 9) = c5
             LET Temp(11) = c6
        CASE 3                                   ! even
             LET Temp( 2) = c1
             LET Temp( 4) = c2
             LET Temp( 6) = c3
             LET Temp( 8) = c4
             LET Temp(10) = c5
             LET Temp(12) = c6
        END SELECT
    END SUB

    SUB StoreSliderVars
        MAT ParamB= ZER
        MAT ParamA= ZER
        MAT Temp  = ZER

        CALL SliderValues
        IF funcflag=1 then
           MAT ParamB = temp
        ELSE
           LET Temp(0)= c0
           MAT ParamA = temp
        END IF
    END SUB

    SUB DrawSliders(reset)
        BOX CLEAR h0wlft-30,h0wrgt+80,h6wbas+20,h0wtop-5
        CALL CheckButtonsClear
        IF reset=1 then
           LET k= 1
           LET c0,c1,c2,c3,c4,c5,c6,c7= 0
           MAT ParamA= ZER
           MAT ParamB= ZER
        END IF

        IF funcFlag=1 then                       ! sine
           LET h0Flag= 0
           MAT Temp  = ParamB
           LET s$    = "b_"
        ELSE                                     ! cosine
           IF termFlag<>2 then
              LET h0Flag= 1
           ELSE
              LET h0Flag= 0
           END IF
           MAT Temp  = ParamA
           LET s$    = "a_"
        END IF

        SELECT CASE termFlag
        CASE 1                                   ! all
             LET h0= 4
             LET h1= 2
             LET h2= 2
             LET h3= 1
             LET h4= 1
             LET h5= 0.5
             LET h6= 0.5
             CALL ResetSliderVars

             LET c0= Temp(0)
             LET c1= Temp(1)
             LET c2= Temp(2)
             LET c3= Temp(3)
             LET c4= Temp(4)
             LET c5= Temp(5)
             LET c6= Temp(6)

             IF funcFlag=2 then CALL h0DrawSlider(s$ & "[ 0]",c0)
             CALL h1DrawSlider(s$ & "[ 1]",c1)
             CALL h2DrawSlider(s$ & "[ 2]",c2)
             CALL h3DrawSlider(s$ & "[ 3]",c3)
             CALL h4DrawSlider(s$ & "[ 4]",c4)
             CALL h5DrawSlider(s$ & "[ 5]",c5)
             CALL h6DrawSlider(s$ & "[ 6]",c6)
        CASE 2                                   ! odd
             LET h1= 2
             LET h2= 1
             LET h3= 0.5
             LET h4= 0.5
             LET h5= 0.25
             LET h6= 0.25
             CALL ResetSliderVars

             LET c1= Temp( 1)
             LET c2= Temp( 3)
             LET c3= Temp( 5)
             LET c4= Temp( 7)
             LET c5= Temp( 9)
             LET c6= Temp(11)

             CALL h1DrawSlider(s$ & "[ 1]",c1)
             CALL h2DrawSlider(s$ & "[ 3]",c2)
             CALL h3DrawSlider(s$ & "[ 5]",c3)
             CALL h4DrawSlider(s$ & "[ 7]",c4)
             CALL h5DrawSlider(s$ & "[ 9]",c5)
             CALL h6DrawSlider(s$ & "[11]",c6)
        CASE 3                                   ! even
             LET h0= 4
             LET h1= 2
             LET h2= 1
             LET h3= 0.5
             LET h4= 0.5
             LET h5= 0.25
             LET h6= 0.25
             CALL ResetSliderVars

             LET c0= Temp( 0)
             LET c1= Temp( 2)
             LET c2= Temp( 4)
             LET c3= Temp( 6)
             LET c4= Temp( 8)
             LET c5= Temp(10)
             LET c6= Temp(12)

             IF funcFlag=2 then CALL h0DrawSlider(s$ & "[ 0]",c0)
             CALL h1DrawSlider(s$ & "[ 2]",c1)
             CALL h2DrawSlider(s$ & "[ 4]",c2)
             CALL h3DrawSlider(s$ & "[ 6]",c3)
             CALL h4DrawSlider(s$ & "[ 8]",c4)
             CALL h5DrawSlider(s$ & "[10]",c5)
             CALL h6DrawSlider(s$ & "[12]",c6)
        END SELECT

        IF h0Flag=1 then CALL h0StepButtons
        CALL h1StepButtons
        CALL h2StepButtons
        CALL h3StepButtons
        CALL h4StepButtons
        CALL h5StepButtons
        CALL h6StepButtons
    END SUB

    SUB ResetSliderVars
        ! h1= 2
        LET h1fLft = -h1
        LET h1fRgt =  h1
        LET h1Label=  h1
        LET h1STik =  0.2
        LET h1LTik =  1

        ! h2= 1,2
        LET h2fLft = -h2
        LET h2fRgt =  h2
        LET h2Label=  h2
        IF h2=1 then
           LET h2STik =  0.1
           LET h2LTik =  0.5
        ELSE
           LET h2STik =  0.2
           LET h2LTik =  1
        END IF

        ! h3= .5,1
        LET h3fLft = -h3
        LET h3fRgt =  h3
        LET h3Label=  h3
        IF h3=.5 then
           LET h3STik =  0.1
           LET h3LTik =  0.5
        ELSE
           LET h3STik =  0.1
           LET h3LTik =  0.5
        END IF

        ! h4= .5,1
        LET h4fLft = -h4
        LET h4fRgt =  h4
        LET h4Label=  h4
        IF h4=.5 then
           LET h4STik =  0.1
           LET h4LTik =  0.5
        ELSE
           LET h4STik =  0.1
           LET h4LTik =  0.5
        END IF

        ! h5= .25,.5
        LET h5fLft = -h5
        LET h5fRgt =  h5
        LET h5Label=  h5
        IF h5=.5 then
           LET h5STik =  0.1
           LET h5LTik =  0.5
        ELSE
           LET h5STik =  0.05
           LET h5LTik =  0.25
        END IF

        ! h6= .25,.5
        LET h6fLft = -h6
        LET h6fRgt =  h6
        LET h6Label=  h6
        IF h6=.5 then
           LET h6STik =  0.1
           LET h6LTik =  0.5
        ELSE
           LET h6STik =  0.05
           LET h6LTik =  0.25
        END IF

        LET h0First= h0fLft
        LET h1First= h1fLft
        LET h2First= h2fLft
        LET h3First= h3fLft
        LET h4First= h4fLft
        LET h5First= h5fLft
        LET h6First= h6fLft

        LET h0Click= h0STik
        LET h1Click= h1STik
        LET h2Click= h2STik
        LET h3Click= h3STik
        LET h4Click= h4STik
        LET h5Click= h5STik
        LET h6Click= h6STik

        CALL h0SliderVariables
        CALL h1SliderVariables
        CALL h2SliderVariables
        CALL h3SliderVariables
        CALL h4SliderVariables
        CALL h5SliderVariables
        CALL h6SliderVariables

        LET h1xPix = (h1fRgt-h1fLft)/slideWidth
        LET h2xPix = (h2fRgt-h2fLft)/slideWidth
        LET h3xPix = (h3fRgt-h3fLft)/slideWidth
        LET h4xPix = (h4fRgt-h4fLft)/slideWidth
        LET h5xPix = (h5fRgt-h5fLft)/slideWidth
        LET h6xPix = (h6fRgt-h6fLft)/slideWidth
    END SUB


    ! --- Graphing Methods ---

    SUB ReDraw
        CALL ResetDistance
        CALL DrawGraph(1,1)
    END SUB

    ! --- This draws the graph of the sum of the terms ---

    SUB DrawGraph(stp,refresh)
        IF refresh=1 then CALL w1ShowGraphLayer
        SET COLOR yellow
        FOR wx= w1Lft to w1Rgt step stp
            LET t= w1Fncx(wx)
            CALL Fourier(t,k,x)
            LET wy= w1Wndy(x)
            IF wy>w1Top and wy<w1Bas then
               PLOT wx,wy;
            ELSE
               PLOT
            END IF
        NEXT wx
        PLOT
    END SUB

    ! --- this draws graph of the term being manipulated ---

    SUB DrawTerm(stp,slider)
        CALL w1ShowGraphLayer
        SET COLOR 4
        FOR wx= w1Lft to w1Rgt step stp
            LET t= w1Fncx(wx)
            CALL FourierTerm(slider,t,x)
            LET wy= w1Wndy(x)
            IF wy>w1Top and wy<w1Bas then
               PLOT wx,wy;
            ELSE
               PLOT
            END IF
        NEXT wx
        PLOT
    END SUB

    ! ------ Target model methods ------
    ! --- compute approximate distance using the slider values ---

    SUB GetDistance(target,D)
        CALL GetTargetValue(target,D1)           ! Actual Distance
        MAT As  = ZER                            ! zero slider cosine arrays
        MAT Bs  = ZER                            ! zero slider sine arrays
        MAT Temp= ZER

        CALL SliderValues
        ! store slider values
        IF funcflag=1 then
           MAT Bs= Temp                          ! copy slider values to sine array
        ELSE
           LET Temp(0)= c0
           MAT As= Temp                          ! copy slider values to cosine array
        END IF

        ! now compute terms for the user defined part of the distance value

        LET D2 = (At(0) - As(0))^2/2
        FOR i= 1 to 12
            LET D2 = D2 + (At(i)-As(i))^2 + (Bt(i)-Bs(i))^2
        NEXT i

        ! and now the final distance
        ! if sliders are exactly right,then  D2 = 0

        LET D = sqr(D1 + D2)
    END SUB


    ! --- Draw Model ---

    SUB DrawModel(target)
        CALL w1ShowGridLayer
        IF target>=0 then
           LET wxnh= w1Wndx(-0.5*pi)             ! negative half pi
           LET wxph= w1Wndx( 0.5*pi)             ! positive half pi

           SET COLOR green
           SELECT CASE target
           CASE 1                                ! square - odd sine
                LET wyn1= w1Wndy(-pi/4)          ! negative
                LET wyp1= w1Wndy( pi/4)          ! positive
                PLOT w1Lft,wyn1; w1x0,wyn1; w1x0,wyp1; w1Rgt,wyp1
           CASE 2                                ! square - odd cosine
                LET wyn1= w1Wndy(-pi/4)          ! negative
                LET wyp1= w1Wndy( pi/4)          ! positive
                PLOT w1Lft,wyn1; wxnh,wyn1; wxnh,wyp1; wxph,wyp1;  wxph,wyn1; w1Rgt,wyn1
           CASE 3                                ! v - inverse cosine
                LET wyn1= w1Wndy(-pi^2/4)        ! negative
                LET wyp1= w1Wndy( pi^2/4)        ! positive
                PLOT w1Lft,wyp1; w1x0,w1y0; w1Rgt,wyp1
           CASE 4                                ! sawtooth? - all sine
                LET wyn1= w1Wndy(-pi/2)          ! negative
                LET wyp1= w1Wndy( pi/2)          ! positive
                PLOT w1Lft,wyn1; w1Rgt,wyp1
           CASE 5                                !
                LET wyn1= w1Wndy(-pi/2)          ! negative
                LET wyp1= w1Wndy( pi/2)          ! positive
                PLOT w1Lft,w1y0; wxnh,wyp1; wxnh,wyn1; wxph,wyp1;  wxph,wyn1; w1Rgt,w1y0
           CASE 6
                LET wyn1= w1Wndy(-pi^2/4)        ! negative
                LET wyp1= w1Wndy( pi^2/4)        ! positive
                PLOT w1Lft,w1y0; wxnh,wyp1; w1x0,w1y0; wxph,wyp1; w1Rgt,w1y0
           END SELECT
        END IF
        CALL w1KeepGraphLayer
    END SUB
END SUB

! ----- end of Fourier Coefficients -----