!! File: Linear Response
!! May 26,2003  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 backclr,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

LET toolHgt= 520
LET toolWid= 780
LET window$= "D'Arbeloff Interactive Math Project"
LET colorscheme= 0

LET title$ = "Linear System Response"

SUB ThisProgram
    CALL ShiftedFunction
    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-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 ---
!! ---------------------------------------------------------

! ***

SUB ShiftedFunction
    DECLARE PUBLIC worklft,workrgt,workbas,worktop,workmidx     ! work area
    DECLARE PUBLIC backclr,black,drkgry,drkmid,midgry,litmid,litgry,white
    DECLARE PUBLIC red,yellow,green,cyan,blue,magenta
    DECLARE PUBLIC slideclr,axisclr,axislabelclr,gridclr,true,false
    DECLARE DEF InfoWithin, QuitWithin

    ! --- help screen array ---

    DIM  info$(1:1)
    MAT READ info$

    DATA "Population Growth: Logistic and Exponential"

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

    DECLARE DEF clamp,roundn,e

    DEF badarg= -0.01234543210

    ! --- functions and parameters ---

    LET bignum= 10^10

    ! DEF f(x)= 0

    DEF delta(t)
        ! delta(t)  makes a vertical arrow with a large head
        !           starting at the t-axis at t = 0
        !           the number 1/b or 1/k should appear next to arrow

        LET f= bignum
        LET g= bignum
        LET h= bignum
    END DEF

    DEF ddelta(t)
        ! delta'(t) makes a vertical arrow at  t = 0
        !           with two heads one above the other
        !           the number 1/k should appear next to arrow

        LET f= bignum
        LET g= bignum
        LET h= bignum
    END DEF

    SUB GetValues
        IF t<0 then
           LET f= 0
           LET g= 0
           LET h= 0
        ELSE                                     ! t is <> 0
           IF m<>0 then
              LET omega= sqr(abs( (b/(2*m))^2 - k/m) )
              IF omega<>0 then
                 LET mk4  = 4*m*k

                 IF b > mk4 then
                    LET r = (-b/(2*m)) + omega
                    LET s = (-b/(2*m)) - omega
                    IF  k <> 0 then
                       LET f = (1/k)*(1 + (s/(2*omega))*e^(r*t) - (r/(2*omega))*e^(s*t))
                       LET g = (1/(2*m*omega))*(e^(r*t) - e^(s*t))
                       LET h = (1/(2*m*omega))*(r*e^(r*t) - s*e^(s*t))
                    ELSE IF  k = 0 then          ! b <> 0
                       LET f = (1/b)*(t - (1/(2*b*omega))*(e^(r*t) - e^(s*t)) )
                       LET g = (1/b)*(1 - (1/(2*b*omega))*(r*e^(r*t) - s*e^(s*t)))
                       LET h = - (1/(2*b^2*omega))*(r^2 * e^(r*t) - s^2*e^(s*t))
                    END IF                       ! k

                 ELSE IF b = mk4 then
                    IF k <> 0 then
                       LET f = (1/k)*(1 - (1 + (b*t/(2*m)))*e^(-b*t/(2*m)))
                       LET g = (b*t/m)*e^(-b*t/(2*m))
                       LET h = (b/m)*(1 - (b^2*t/(2*m^2)))*e^(-b*t/(2*m))
                    ELSE IF k = 0 then           !  b = 0
                       LET f = t^2/(2*m)
                       LET g = t/m
                       LET h = 1/m
                    END IF                       ! k

                 ELSE IF b < mk4 then
                    IF k <> 0 then
                       LET f = (1/k)*(1 - e^(-b*t/(2*m))*(cos(omega*t) + (b/(2*m*omega))*sin(omega*t)))
                       LET g = (1/(m*omega))*e^(-b*t/(2*m))*sin(omega*t)
                       LET h = (1/m)*e^(-b*t/(2*m))*(cos(omega*t) - (b/(2*m*omega))*sin(omega*t))
                    ELSE IF k = 0 then
                       ! ??
                    END IF                       ! k
                 END IF                          ! b
              END IF
           ELSE                                  ! m = 0 - it's a first order system
              IF b <> 0 then
                 LET f = (1/k)*(1 - e^(-(k/b)*t))
                 LET g = (1/b)*e^(-(k/b)*t)
                 LET h = -(k/b^2)*e^(-(k/b)*t) + (1/b)*delta(t)
              ELSE IF b = 0 then
                 IF k <> 0 then                  ! k is not zero - it's a zeroth order system
                    LET f =  1/k
                    LET g = (1/k)*delta(t)
                    LET h = (1/k)*ddelta(t)
                 ELSE                            ! all params zero
                    ! don't plot - all three curves are turned off
                 END IF                          ! k
              END IF                             ! b

           END IF                                ! m
        END IF                                   ! t
    END SUB


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

    LET wwid  = 300
    LET whgt  = 300
    LET fwid  =   4
    LET fhgt  =  40
    LET vrule1= worklft + 80
    LET vrule2= vrule1 + wwid + 120
    LET vrule3= vrule2 + wwid + 60
    LET gstp  = 2


    ! ----- graph window 1 -----

    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   = 1

    LET w1xPiFlag= 0
    LET w1xMult  = 1

    LET w1yPiFlag= 0
    LET w1yMult  = 1

    LET w1Lft = vrule1
    LET w1Rgt = w1Lft + 300
    LET w1Top = worktop + 80
    LET w1Bas = w1Top + 300

    LET w1fLft= -1
    LET w1fRgt=  14
    LET w1fBas= -4
    LET w1fTop=  4

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

    LET w1xGridstep= 0                           ! horizontal grid intervals
    LET w1yGridstep= 0                           ! vertical grid intervals

    LET w1xSTik  = .5                            ! horizontal axis Tik marks
    LET w1xLTik  = 1
    LET w1xLabel = 1
    LET w1xFirst = w1fLft

    LET w1ySTik  = 0                             ! vertical axis Tik marks
    LET w1yLTik  = .50
    LET w1yLabel = .50
    LET w1yFirst = w1fBas

    ! --- Plane 1 methods ---

    DECLARE DEF w1fncx,w1fncy,w1wndx,w1wndy      ! window/function transforms
    DECLARE DEF w1Within,w1wWithin,w1fWithin

    CALL w1Variables

    SUB w1Init
        BOX CLEAR w1Lft-25,w1Rgt+20,w1Bas+15,w1Top-20
        CALL w1DrawPlane(1,1,1)

        CALL SetTextFont(1,12,"bold")
        CALL PlotTextLJ(w1Rgt+8,w1y0+3,w1xAx$,litgry)

        CALL PlotTextCJ(w1x0,w1Top-11,w1yAx$,litgry)

        CALL SetTextFont(1,9,"normal")
        CALL w1KeepGridLayer
    END SUB

    ! --- Slider parameters and methods ---


    ! --- h1 slider data ---

    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 h1Flag= 1

    LET h1PiAxis= 0
    LET h1Mult  = 1

    LET h1clr   = cyan
    LET h1name$ = "m"
    LET h1form$ = "---%.##"
    LET h1Places= 2

    LET h1axis  = w1Bas - 100                    !13
    LET h1wLft  = w1Rgt + 100
    LET h1wRgt  = h1wLft + 200

    LET h1fLft  = 0
    LET h1fRgt  = 8

    LET h1STik  = .5                             ! short tick marks
    LET h1LTik  = 1                              ! long tick marks
    LET h1Label = 1                              ! labels
    LET h1First = h1fLft                         ! first tick mark
    LET h1Click = .5

    ! --- h1 slider methods ---

    DECLARE DEF h1Within

    CALL h1SliderVariables

    SUB h1Init
        CALL h1SliderVariables
        CALL h1DrawSlider(h1name$,m)
    END SUB


    ! --- h2 slider data ---

    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 h2Flag  = 1

    LET h2PiAxis= 0
    LET h2Mult  = 1

    LET h2clr   = cyan
    LET h2name$ = "b"
    LET h2form$ = "--%.##"
    LET h2Places= 2

    LET h2axis  = h1Axis + 45
    LET h2wLft  = h1wLft
    LET h2wRgt  = h1wRgt

    LET h2fLft  = 0
    LET h2fRgt  = 4

    LET h2STik  = .5                             ! short tick marks
    LET h2LTik  = 1                              ! long tick marks
    LET h2Label = 1                              ! labels
    LET h2First = h2fLft                         ! first tick mark
    LET h2Click = 1


    ! --- h2 slider methods ---

    DECLARE DEF h2Within

    CALL h2SliderVariables

    SUB h2Init
        CALL h2SliderVariables
        CALL h2DrawSlider(h2name$,b)
    END SUB


    ! --- h3 slider data ---

    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   = cyan
    LET h3name$ = "k"
    LET h3form$ = "--%.##"
    LET h3Places= 3

    LET h3axis  = h2axis + 45
    LET h3wLft  = h2wlft
    LET h3wRgt  = h2wrgt

    LET h3fLft  = 0
    LET h3fRgt  = 2

    LET h3STik  = 0.5                            ! short tick marks
    LET h3LTik  = 1                              ! long tick marks
    LET h3Label = 1                              ! labels
    LET h3First = h3fLft                         ! first tick mark
    LET h3Click = 1


    ! --- h3 slider methods ---

    DECLARE DEF h3Within
    SUB h3Init
        CALL h3SliderVariables
        CALL h3DrawSlider(h3name$,k)
    END SUB
    SUB h3Clear
        BOX LINES h3wLft-20,h3wRgt+30,h3wBas+5,h3wTop-5
    END SUB


    ! --- t1 text - Linear Equation ---

    ! m x" + b x' + k x 

    LET t1BasLn = w1Top + 8
    LET t1Lft   = h1wLft
    LET t1Rgt   = t1Lft + 300
    LET t1Top   = t1BasLn - 15
    LET t1Bas   = t1BasLn +  5
    LET t1Clr1  = cyan

    SUB t1Init
        CALL SetTextFont(1,12,"bold")
        CALL PlotTextLJ(t1Lft,t1BasLn,"mx'' + bx' + kx" ,white)
    END SUB

    SUB t1ClearValue
        BOX CLEAR t1Eqx-2,t1Rgt,t1Bas2,t1Top2
    END SUB


    ! --- t2 text - Linear Equation ---

    LET t2BasLn1= w1Top + 8 + 40
    LET t2BasLn2= t2BasLn1 + 20
    LET t2BasLn3= t2BasLn2 + 20
    LET t2Lft   = h1wLft
    LET t2Rgt   = t2Lft + 300
    LET t2Top   = t2BasLn1 - 15
    LET t2Bas   = t2BasLn3 +  5
    LET t2Clr1  = cyan

    SUB t2Init
        CALL SetTextFont(1,12,"bold")
        CALL PlotTextLJ(t2Lft,t2BasLn1,"Step Response" ,yellow)
        CALL PlotTextLJ(t2Lft,t2BasLn2,"Impulse Response" ,cyan)
        CALL PlotTextLJ(t2Lft,t2BasLn3,"Doublet Response" ,green)
        !step response	f
        !impulse response	g
        !doublet response	h
    END SUB

    SUB t2ClearValue
        BOX CLEAR t2Eqx-2,t2Rgt,t2Bas2,t2Top2
    END SUB

    ! --- t5 text - rollover x and y values ---

    LET t5BasLn1 = w1Bas + 35
    LET t5BasLn2 = t5BasLn1 + 20
    LET t5Lft    = w1Lft
    LET t5Rgt    = t5Lft + 150
    LET t5Top    = t5BasLn1 - 15
    LET t5Bas    = t5BasLn2 +  5
    LET t5Form$  = "---%.##"
    LET t5Label1$= "x = "
    LET t5Label2$= "y = "
    CALL StringWidth(t5Label2$,sw)
    LET t5Eqx    = t5Lft + sw
    LET t5Clr1   = cyan

    SUB t5Clear
        BOX CLEAR t5Lft,t5Rgt,t5Bas,t5Top
        LET t5State= 0
    END SUB

    SUB t5ClearValue
        BOX CLEAR t5Eqx,t5Rgt,t5Bas,t5Top
    END SUB

    SUB t5Init
        CALL SetTextFont(1,12,"bold")
        CALL PlotTextRJ(t5Eqx,t5Basln1,t5Label1$,t5Clr1)
        CALL PlotTextRJ(t5Eqx,t5Basln2,t5Label2$,t5Clr1)
        CALL t5Value
    END SUB

    SUB t5Value
        CALL t5ClearValue
        LET x$= trim$(using$("####",x+1790))
        LET y$= trim$(using$(t5Form$,y))
        CALL PlotTextLJ(t5Eqx,t5Basln1,x$,t5Clr1)
        CALL PlotTextLJ(t5Eqx,t5Basln2,y$,t5Clr1)
        LET t5State= 1
    END SUB

    ! --- t6 text - profit ---

    LET t6BasLn  = tb1Bas + 23
    LET t6Top    = t6BasLn - 15
    LET t6Bas    = t6BasLn +  5
    LET t6Form$  = "---%.##"
    LET t6Label$ = "profit = "
    CALL StringWidth(t6Label$&t6Form$,sw)
    LET t6Lft    = tb1Lft
    LET t6Rgt    = t6Lft + 200
    CALL StringWidth(t6Label$,sw)
    LET t6Eqx    = t6Lft + sw
    LET t6Clr1   = litgry

    SUB t6Clear
        BOX CLEAR t6Lft,t6Rgt,t6Bas,t6Top
        LET t6State= 0
    END SUB

    SUB t6ClearValue
        BOX CLEAR t6Eqx,t6Rgt,t6Bas,t6Top
    END SUB

    SUB t6Init
        CALL SetTextFont(1,12,"bold")
        CALL PlotTextRJ(t6Eqx,t6BasLn,t6Label$,t6Clr1)
        CALL t6Value
    END SUB

    SUB t6Value
        CALL t6ClearValue
        !LET y = f(x)
        LET p = 55.45*x - y
        LET p$= trim$(using$(t6Form$,p))
        CALL PlotTextLJ(t6Eqx,t6Basln,p$,t6Clr1)
        LET t6State= 1
    END SUB


    ! --- 

    LET btnHgt= 19
    LET bfRgt = w1Rgt
    LET bfLft = bfRgt - 75
    LET bfTop = w1Bas + 30
    LET bfBas = bfTop + btnHgt

    SUB Buttons
        CALL SetTextFont(1,12,"Bold")
        CALL DrawButton(bfLft,bfRgt,bfBas,bfTop,5,"")
    END SUB


!    ! --- radio boxes ---
!
!    DECLARE PUBLIC r1cnt, r1stp, r1siz
!    DECLARE PUBLIC r1Lft, r1Rgt, r1Bas, r1Top, r1Name$, r1NameClr
!    DECLARE PUBLIC r1NameList$(),r1ColorList()
!
!    LET r1cnt= 3                                 ! box count
!    LET r1Lft= bfLft
!    LET r1Top= bfBas + 45
!
!    CALL r1SetVars
!
!    LET r1Name$  = "Model"
!    LET r1NameClr= litgry
!
!    MAT redim r1NameList$(1:r1cnt)               ! text strings
!    DATA "Logistic","Exponential","Both"
!    MAT READ r1NameList$
!
!    MAT redim r1ColorList(1:r1cnt)               ! colors
!    DATA 26,24,21
!    MAT READ r1ColorList
!
!    DECLARE DEF r1Within


    ! --- default parameters ---

    !    LET L= 197.27                                ! 0 to 200
    !    LET a=  49.58                                ! 0 to 100
    !    LET k=   0.03134                             ! 0 to 0.5

    !    LET b= 1.031                                 ! 0 to 2
    !    LET c= 3.926                                 ! 0 to 4

    LET tb1Pntr = 1

    LET m,oldm  = 1
    LET b,oldb  = 0
    LET k,oldk  = 2

    LET f$      = form$
    LET r1num   = 1
    LET eq      = r1num

    ! --- Draw screen ---

    CALL InitScreen

    SUB InitScreen
        BOX CLEAR worklft,workrgt,workbas,worktop

        CALL w1Init
        CALL w1LogGraph

        CALL h1Init
        CALL h2Init
        CALL h3Init

        CALL t1Init
        CALL t2Init
    END SUB


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

    DO
       LET initflag= 1
       BOX KEEP w1Lft-5,w1Rgt+5,w1Bas+5,w1Top-5 in temp$
       DO
          GET MOUSE: mx,my,ms
          !          IF w1Within(mx,my)=1 then
          !             IF t5State=0 then CALL t5init
          !             IF dataPntr=3 then
          !                IF t6State=0 then CALL t6init
          !             END IF
          !             IF mx<>oldmx then
          !                LET x = round(w1Fncx(mx),-1)
          !                LET y = round(f(x),2)
          !                IF dataPntr=3 then
          !                   CALL t5Value
          !                   CALL t6Value
          !                   LET wx= w1Wndx(x)
          !                   LET wy= w1Wndy(y)
          !                   IF w1wWithin(wx,wy)=true then
          !                      LET clr= litgry
          !                      BOX SHOW temp$ at w1Lft-5,w1Bas+5
          !                      LET r = 55.45*x
          !                      LET wr= w1Wndy(r)
          !                      IF wp>w1Top and wp<w1Bas and wy>w1Top and wy<w1Bas then
          !                         CALL PlotLine(wx,wy, wx,wr, clr)
          !                      END IF
          !                      LET p = r-y
          !                      LET wp= w1Wndy(p)
          !                      CALL PlotDiamondClr(wx,wp,litgry)
          !                      LET w1ClearFlag= 1
          !                   ELSE IF w1ClearFlag=1 then
          !                      BOX SHOW temp$ at w1Lft-5,w1Bas+5
          !                      CALL t5Clear
          !                      CALL t6Clear
          !                      LET w1ClearFlag= 0
          !                   END IF
          !                   LET oldmx= mx
          !                ELSE
          !                   CALL t5Value
          !                   LET wx= w1Wndx(x)
          !                   LET wy= w1Wndy(y)
          !                   IF w1wWithin(wx,wy)=true then
          !                      LET clr= litmid
          !                      BOX SHOW temp$ at w1Lft-5,w1Bas+5
          !                      CALL PlotLine(wx,w1y0, wx,wy, clr)
          !                      CALL PlotLine(wx,wy, w1x0,wy, clr)
          !                      LET w1ClearFlag= 1
          !                   ELSE IF w1ClearFlag=1 then
          !                      BOX SHOW temp$ at w1Lft-5,w1Bas+5
          !                      CALL t5Clear
          !                      LET w1ClearFlag= 0
          !                   END IF
          !                   LET oldmx= mx
          !                END IF
          !             END IF
          !          ELSE
          !             IF t5State=1 then CALL t5Clear
          !             IF t6State=1 then CALL t6Clear
          !             IF w1ClearFlag=1 then
          !                BOX SHOW temp$ at w1Lft-5,w1Bas+5
          !                LET w1ClearFlag= 0
          !             END IF
          !          END IF
       LOOP until ms= 2


       IF h1Within(mx,my)=1 then
          IF my<h1axis then
             CALL h1ClickEvent(ms,m)
          ELSE
             CALL h1DragEvent(ms,m)
          END IF
       ELSE IF h2Within(mx,my)=1 then
          IF my<h2axis then
             CALL h2ClickEvent(ms,b)
          ELSE
             CALL h2DragEvent(ms,b)
          END IF
       ELSE IF h3Within(mx,my)=1 then
          IF my<h3axis then
             CALL h3ClickEvent(ms,k)
          ELSE
             CALL h3DragEvent(ms,k)
          END IF

          !       ELSE IF h4Within(mx,my)=1 then
          !          !  call t4clearvalue
          !          CALL w1ShowDataLayer
          !          CALL w1LogGraph
          !          CALL w1KeepGraphLayer
          !          IF my<h4axis then
          !             CALL h4ClickEvent(ms,b)
          !          ELSE
          !             CALL h4DragEvent(ms,b)
          !          END IF
          !       ELSE IF h5Within(mx,my)=1 then
          !          !  call t4clearvalue
          !          CALL w1ShowDataLayer
          !          CALL w1LogGraph
          !          CALL w1KeepGraphLayer
          !          IF my<h5axis then
          !             CALL h5ClickEvent(ms,c)
          !          ELSE
          !             CALL h5DragEvent(ms,c)
          !          END IF


          !       ELSE IF r1Within(mx,my)=1 then            ! radio boxes for h
          !          CALL MouseUp(mx,my,ms)
          !          LET  r1num = int((my-r1Top)/r1stp)+1
          !          CALL r1SetCheckBox(r1num)
          !          LET  eq= r1num
          !          IF eq=2 then
          !             LET h3Flag= 1
          !          ELSE
          !             LET h3Flag= 0
          !          END IF
          !          ! CALL LoadData(dataPntr,eq)
          !          CALL InitScreen

          !       ELSE IF m1Within(mx,my)=1 then            ! read menu
          !          CALL m1ButtonUp(ms)
          !          CALL m1ReadMenu
          !          LET  dataPntr = m1Equation
          !          ! CALL LoadData(dataPntr,eq)
          !          CALL InitScreen

       ELSE IF mx>bfLft and mx<bfRgt and my>bfTop and my<bfBas then  ! best fit
          CALL MouseButtonUp(bfLft,bfRgt,bfBas,bfTop,ms)
          ! CALL LeastSquares(DataCnt,a,b,crc,mnx,mny)
          CALL BestFitReDraw
          !  call t4init

       ELSE IF infoWithin(mx,my,ms)=1 then
          CALL infoButtonUp(ms)
          CALL InfoPage(Info$)
          CALL InitScreen
       ELSE IF quitWithin(mx,my,ms)=1 then
          CALL quitButtonUp(ms)
          EXIT SUB
       ELSE
          CALL MouseUp(mx,my,ms)
       END IF
    LOOP

    ! --- mouse events ---

    SUB BestFitRedraw
        CALL w1LogGraph

        CALL h1Mark(L)
        CALL h2Mark(a)
        CALL h3Mark(k)
    END SUB

    SUB Redraw
        !  call t2function
        CALL w1LogGraph
        CALL h2Mark(a)
        IF h2Flag=1 then CALL h3Mark(b)
    END SUB


    ! ----- h1 slider -----

    SUB h1ClickEvent(ms,m)
        CALL h1GetClickVal(ms,h1Click,m)
        CALL h1Action
    END SUB
    SUB h1DragEvent(ms,m)
        DO
           CALL h1GetDragVal(ms,h1Places,m)
           CALL h1Action
        LOOP until ms=3
    END SUB

    SUB h1Action
        IF m<>oldm then
           CALL w1ShowGraphLayer
           CALL w1LogGraph
           !  call t2function
           LET oldm= m
        END IF
    END SUB


    ! ----- h2 slider -----

    SUB h2ClickEvent(ms,b)
        CALL h2GetClickVal(ms,h2Click,b)
        CALL h2Action
    END SUB
    SUB h2DragEvent(ms,b)
        DO
           CALL h2GetDragVal(ms,h2Places,b)
           CALL h2Action
        LOOP until ms=3
    END SUB

    SUB h2Action
        IF b<>oldb then
           CALL w1ShowGraphLayer
           CALL w1LogGraph
           !  call t2function
           LET oldb= b
        END IF
    END SUB


    ! ----- h3 slider -----

    SUB h3ClickEvent(ms,k)
        CALL h3GetClickVal(ms,h3Click,k)
        CALL h3Action
    END SUB
    SUB h3DragEvent(ms,k)
        DO
           CALL h3GetDragVal(ms,h3Places,k)
           CALL h3Action
        LOOP until ms=3
    END SUB

    SUB h3Action
        IF k<>oldk then
           CALL w1ShowGraphLayer
           CALL w1LogGraph
           !  call t2function
           LET oldk= k
        END IF
    END SUB


    ! --- draw the function graphs ---

    SUB w1LogGraph                               ! internal
        LOCAL x,y,wx,wy
        CALL w1ShowGridLayer

        FOR wx= w1Lft to w1Rgt
            LET t= w1Fncx(wx)
            CALL GetValues

            SET COLOR yellow
            LET wy= w1Wndy(f)
            IF w1wWithin(wx,wy)=true then PLOT wx,wy

            SET COLOR cyan
            LET wy= w1Wndy(g)
            IF w1wWithin(wx,wy)=true then PLOT wx,wy

            SET COLOR green
            LET wy= w1Wndy(h)
            IF w1wWithin(wx,wy)=true then PLOT wx,wy
        NEXT wx
        PLOT
    END SUB
END SUB

! --- end of regression ex1 function ----------------