MATLAB: What is the difference between int and integral.

integralintegrationnumerical integration

Hello everyone

I want to get explained how to decide wheather use function "int" or "integral".

What is the basic difference between them? will they give same answer for a given function?

Thank you very much in advance.

Best Answer

The int function integrates symbolic expressions (or does its best, consdidering that not all expressions have analytic integrals).

The integral function is for numeric functions, usually anonymous functions.

The documentation pages for those functions explain them better than I can, so I provided links to them.

Related Solutions

MATLAB: How to solve equations with symsum inside

You have three symbolic variables; you should be naming your variable of summation specifically.
In MATLAB, symsum is for the case where the variable of summation is used in the calculation, not to add a definite list of terms. You should create a vector of terms and add them with sum(), or create a total using a loop. Using arrayfun() can help:

t1 = arrayfun(@(k) ((-1/mu2 +exp(mu2*delta)/mu2)*(SpreadCLPbp(k)-(-mu1/mu2+(mu1/mu2+SpreadCLPbp(k))*exp(mu2*delta)))/(mu1*sigma/(2*mu2^2)-sigma^2/mu2*(mu1/mu2+SpreadCLPbp(k))*exp(mu2*delta)+sigma^2/mu2*(mu1/(2*mu2)+SpreadCLPbp(k))*exp(2*mu2*delta)), 1:N, 'Uniform', 0);
S1 = sum( horzcat(t1{:}) );

solve() is for analytic solutions, when you need the result to be the formula for the solution. Your chances of being able to find the exact formula for this with your available resources are pretty minimal. You should consider using vpasolve() to get a symbolic numeric solution; or you should consider using matlabFunction() and fsolve() to get a pure numeric solution.

MATLAB: How to make double integration

You are creating f1 and f2 as symbolic expressions, but you are attempting ot use dblquad() to do the integration. dblquad() takes a function handle, not a symbolic expression. Try

C2_1(i,n)=dblquad(matlabFunction(z(i,n)),inf,Sast(i-1,n),-inf,Sast(i-1,n))

Are you sure you want to go from +infinity downward to Sast(i-1,n) for the first variable? You go from -infinity upward to Sast(i-1,n) for the second variable.

Best Answer

Related Solutions

MATLAB: How to solve equations with symsum inside

MATLAB: How to make double integration

Related Question