Values in function handle (this worked for inline...)

I want to create sets of random linear functions: m*x+b for many different m values and b values. I used to do something like this:

s = sprintf('%d*x+%d',randi(10), randi(3))

f = inline(s)

and I'd end up with an f nicely defined in terms of my random variables (f = 8x+2). Then I can plot and/or evaluate this function for any x.

How do I do something similar with function handles? I have tried doing:

F = @(x) s;

but it appears that it substitutes s in and doesn't understand x is an argument (so F(1) = 8*x+2, not 8*1+2).

I obviously do NOT want to create a brand new function file (which is why I want inline functions in the first place).

Anyone have any ideas?

Regards,

Dr. Dostert

Answer 1

[Star Strider]

% Preferred: 
F = @(b,x) b(1).*x + b(2);
% Less preferred: 
F = @(m,b,x) m.*x + b;

The first is preferred because you can use it in a nonlinear or other solver if you so choose. It also has both parameters as a single vector ‘b’, making it easier to program.

The second is a bit more intuitive (individual parameters, not a vector of parameters), but doesn’t have the flexibility of the first.