Trying to solve an integration with several functions, each of which is dependent upon a single variable

Hello,

I am attempting to perform an integration using the following formulas:

strain = @(x) (eb-et)/h*x+et;
Cstress = @(x) -Cf*(2*strain(x)/Cec-(strain(x)/Cec).^2);
Cforcef = @(x) Cphi*b*Cstress(x)/1000;
Cmomentf = @(x) Cforcef(x)*(h/2-x)/1000;

All variables are defined except for x. I then perform the following integration:

Caxial = integral(Cforcef,0,limit);
Cmoment = integral(Cmomentf,0,limit);

The first one (Caxial) works fine, however the second (Cmoment) gives me the following error:

Error using  * 
Inner matrix dimensions must agree.

Error in @(x)Cphi*b*Cstress(x)*(h/2-x)/1000

Error in integralCalc/iterateScalarValued (line 314)
                fx = FUN(t);

Error in integralCalc/vadapt (line 133)
            [q,errbnd] = iterateScalarValued(u,tinterval,pathlen);

Error in integralCalc (line 76)
        [q,errbnd] = vadapt(@AtoBInvTransform,interval);

Error in integral (line 89)
Q = integralCalc(fun,a,b,opstruct);

Does anyone know why this is?

Thank you for your help!

Answer 1

[Walter Roberson]

CForcef(x) returns a vector if x is a vector. (h/2-x) returns a vector if x is a vector. You ask for matrix multiplication, "*" between the two vectors. That could only work if one of the vectors is a row vector and the other is a column vector, because interior dimensions must be the same for matrix multipication. (A x B) * (C x D) is only allowed if B = C, so in the case of (1xN) * (1xN), that would require N = 1.

Perhaps you want .* instead of *

[Connor Langford]

Thanks Walter!