function [src] = get_ricker(t,srcamp,fcenter)
% function [t,numt,src] = get_ricker(t,srcamp,fcenter)    

tc  = 1./fcenter;	
        
src = -srcamp.*(1 - 2.*(pi.*fcenter.*(t - tc)).^2).*exp(-(pi.*fcenter.*(t - tc)).^2);