Please could someone hlep me with my last post on curve fitting? I just need some guidance or an example of how to formulate a curve fitting problem like this  I'm not even certain if the lsfit routines are the ones I should be trying to figure out how to use for the type of problem I have.
in the simplest terms I can think of I have a measured curve of points x,y
eg the 3 points (1,1), (2,7), (3,4)
I want to fit this curve as a weighted sum of other (constant) curves.
For example with the two curves below
x y x y 1 0 1 1 2 3.5 2 0 3 1 3 2
the y values of the measured curve could be fit exactly by multiplying the set of y values for the first constant curve by 2 and adding 1 times the second set of y values.
My question then is how to formulate this in lsfitcreate? (if that is how it should be done?)
apologies if this is a really basic question but I'm not a mathamatician or a programmer  but I am eager to learn
thanks in anticipation
