MATLAB: Declare ‘eval’ function in Embedded MATLAB

Question

I made a secant method for complicated equation in MATLAB edit space. Like this… Function y = fcn(st, cq, a, g, …) f=''3600 * st * cq * a * ((((2 * g * gam * pi)……….'; (Flow Function eq)

Of course, there is simple secant method.

n=0; x = xa; fa = eval(f); x = xb; fb = eval(f); …….

and then I put this script in Embedded MATLAB of Simulink. For 'eval' function, I also put 'eml.extrinsic('eval') in it.

When I start the simulation, I could see an error *"Call to MATLAB function aborted : Error using ==> eval Undefined function or variable 'st'."*

Thanks for your help.

Answer 1

And does "st" indeed exist in your matlab workspace at the time? When you construct a string like that, the current value of the variable is not recorded.

If it is allowed on embedded systems, you would be better of constructing f as an anonymous function

f = @(x,n) 3600 * st * cq etc

and then you would invoke

fa = f(x, n);
fb = f(x, n);