"Sulaiman Rabbaa" wrote in message <j8c3fp$8kv$1@newscl01ah.mathworks.com>...
> Hello
> I need help to solve the following integral equation:
> double integral (with respect to x and y) of 137.03.*y.^2./((0.238.*exp(0.067.*y.^2)+1).*(w5.26.*x.*y2.63).*(w5.26.*x.*y+2.63))=1+8478./(10828w.^21.13.*j.*w)
> xmin=1, xmax.=1, ymin=0, ymax=inf
> I want to find w which is complex number.
> I tried the following code:
> f=@(w) dblquad(@(x,y) 137.03.*y.^2./((0.238.*exp(0.067.*y.^2)+1).*(w5.26.*y.*x2.63).*(w5.26.*y.*x+2.63)),1,1,0,100)18478./(10828w.^2j.*w.*1.13)
> V=fsolve(f,160)
> There are some singularities. How can I solve the problem
Hi,
The NewtonRaphson solution below gives w = (78.1093  0.2275i). Another solution is w = (78.1093  0.2275i).
f = @(x,y,w) 137.03.*y.^2./(0.238.*exp(0.067.*y.^2)+1) ...
./(w5.26.*x.*y2.63)./(w5.26.*x.*y+2.63);
df = @(x,y,w) 137.03.*y.^2./(0.238.*exp(0.067.*y.^2)+1) ...
./(w5.26.*x.*y2.63).^2./(w5.26.*x.*y+2.63).^2 ...
.*2.*(5.26.*x.*yw);
g = @(w) quad2d(@(x,y)f(x,y,w),1,1,0,100);
dg = @(w) quad2d(@(x,y)df(x,y,w),1,1,0,100);
h = @(w) g(w)  1  8478./(10828w.^21.13i.*w);
dh = @(w) dg(w)  8478.*(2*w+1.13i)./(10828w.^21.13i.*w).^2;
w = 801i;
dw = 1;
while abs(dw) > 1e9 && abs(w) < 1e6
dw = h(w)/dh(w);
w = w + dw;
end
/Jonas
