i have a basic function exp(-x.^2).*log(x).^2 which i integrate in a certain interval. i want to multiply my basic function with a vectoric coefficient called coef_vec that varies with the interval. so if the integral is at 5 my basic function whould be multiplied with coef_vec(5). i know that its som how turning the integral into a loop. Is it possible in matlab? Thanks.
coef_vec=linspace(1,10,100)
fun = @(x)coef_vec*exp(-x.^2).*log(x).^2;
q = integral(fun,1,10);
If you have a closed-form expression for the weighting function, you can use it directly. Here, the weight is linear, so you can replace coef_vec by xand be ok.
fun = @(x)x.*exp(-x.^2).*log(x).^2;
q = integral(fun,1,10);
If not, an option is to define coef_vec on a larger interval, interpolate it with a suitable closed-form interpolating function, and use this under the integral.
Or, simply, evaluate the integral with a function like trapz. Here is a comparison, with close results
coef_vec=linspace(1,10,100);
fun0 = @(x)exp(-x.^2).*log(x).^2;
fun1 = @(x)x.*exp(-x.^2).*log(x).^2;
q1 = integral(fun1,1,10);
q2 = trapz(coef_vec,coef_vec.*fun0(coef_vec));
disp([q1 q2])
>> 0.0245 0.0245
