Hi Pascale,
The matlabFunction function should be used on a symbolic expression or function. For example:
syms x y
f = x^2 + y^2;
f is a symbolic function in the above.
I suppose that you are executing something like:
>> syms x y
>> pos = [x;y];
>> l1 = 1;
>> l2 = 1;
>> th_fnc = matlabFunction(inverse_kin(l1,l2,pos))
th_fnc =
@(x,y)[(angle(x+y.*1i)-acos(sqrt(x.^2+y.^2).*(1.0./2.0))+pi.*angle(x+y.*1i).*2.0<angle(x+y.*1i)-acos(sqrt(x.^2+y.^2).*(1.0./2.0)));acos(x.^2.*(1.0./2.0)+y.^2.*(1.0./2.0)-1.0)]
When I do the above and then try on very simple inputs, I get the same output:
1. Try the original function:
>> x = sym('2');
>> y = sym('2');
>> inverse_kin(1,1,[x;y])
ans =
pi/4 - acos(2^(1/2)) + pi^2/2 < pi/4 - acos(2^(1/2))
acos(3)
2. Try the generated symbolic function:
>> th_fnc(x,y)
ans =
pi/4 - acos(2^(1/2)) + pi^2/2 < pi/4 - acos(2^(1/2))
acos(3)
Therefore, can you give me an example for which you do not get the same output? What were you expecting to see?
You should make sure that the inputs to the symbolic function are symbolic as well. For example, th_fnc(2,2) is not the same as th_fnc(x,y) with x and y being symbolic variables containing the numeric value 2. You might see differences if the inputs are not symbolic. For example:
>> inverse_kin(1,1,[2;2])
ans =
0.7854 - 0.8814i
0.0000 + 1.7627i
>> th_fnc(2,2)
ans =
0.0000 + 0.0000i
0.0000 + 1.7627i
