is there a way to determine the fourier series of a curve by matlab?

so i assume my curve is of the form y=a(sin(t-c)+d)

i have the curve, i dont understand how to work out the coefficients a,b,c,d

would least squares be appropriate?

[Walter Roberson]

What representation do you have for the curve?

If you have lists of points then do you have the curve fitting toolbox? cftool has fourier options.