How to execute double for loop?
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Athira T Das
on 30 Jan 2024
Commented: Walter Roberson
on 31 Jan 2024
I have an equation
.
This particular equation is for an z value.
But I have an array of z and I need to evaluate get C as an array. But currently I have an error in the final step. Can anyone help me?
clc;close all;clear all;
syms r ph phi
mu=1
w0=0.01;
lambda=532*10^-9;
R=0.035;
omega=.1;
zr=pi.*w0.^2./lambda;
k=2*pi/lambda;
z=[1.037 2.014 4.91 6.638 8.097 10.179 12.804 14.491 16.594 18.136 20.468 22.842 26.091 28.695 31.132 32.486 34.735 36.173 38.068 40.256 42.089 44.672 46.358 48.066 50.045 52.816 54.523 56.191 58.919 61.127 62.085 64.106 66.127 67.856 70.084 72.272 74.189 76.063 78.064 80.522 82.876 85.856 86.147 88.189 90.606 92.606 94.584 96.23 98.336 99.794 100 ];
T1=[0.261864786659278 0.0279450575402681 0.0167207441613120 0.0585405683053739 0.0467736536041428 0.0721143056065063 0.0204055105411778 0.0414970149223034 0.0370574720556092 0.0323354183816648 0.0557187803983150 0.0209702231071337 0.0523815841575279 0.0478073675740971 0.0452486568524416 0.0454216694742521 0.0455017342270441 0.0433366921457154 0.0416287144440869 0.0325563861379645 0.0453942497662185 0.0308978986984992 0.0388337989311703 0.0395470194181856 0.0412953384586318 0.0359798229891002 0.0343224345520140 0.0388190479592265 0.0357132945620167 0.0338578554357400 0.0294508197964149 0.0346296299864533 0.0328074293196396 0.0327552539365064 0.0332008509577915 0.0266013611176686 0.0351599194601709 0.0325287304943849 0.0320666044429463 0.0321364098469872 0.0321092261908771 0.0104350167431096 0.0155659791192790 0.00845361754599249 0.0304932945576984 0.0286130247196421 0.0302806888132458 0.0290252186616402 0.0323193263219266 0.0321277263184264 0.0320992548815438] ;
L=3;
N=2*L+1;
m0=1;
m=1 ;
M=[-2 -1 0 1 2];
M0=linspace(-L,L,N);
%to calculate P(m/m0)
wz=w0.*sqrt(1+(z./zr).^2) ;
Con1 = (1i./(2.*lambda.*z)).*exp((-1i.*k.*r.*r)./(2.*z));
for l2=0:m
E =-1./(wz.^2) + (1i.*k)./(2.*z) ;
E2 = exp((((omega/2)-(r.*cos(ph))).^2)./E).* exp((((omega/2)-(r.*sin(ph))).^2)./E).*hermiteH(l2,1i*(omega./2 - r.*cos(ph))./sqrt(E)).*hermiteH(m-l2,1i*(omega./2 - r.*sin(ph))./sqrt(E)) + exp((((-omega/2)-(r.*cos(ph))).^2)./E).* exp((((-omega/2)-(r.*sin(ph))).^2)./E).*hermiteH(l2,1i*(-omega./2 - r.*cos(ph))./sqrt(E)).*hermiteH(m-l2,1i*(-omega./2 - r.*sin(ph))./sqrt(E));
I2 = ((1i).^(m-l2)).*nchoosek(m,l2).*E2;
end
Is = (Con1.*conj(Con1)).*I2.*conj(I2);
%to calculate Sum over P(m/m0)
parfor j= 1:length(z)
for m0=1:length(M0)
IQ1 =Is(j).*r.*exp((-2.*r.*r)./(T1(j)^2)).*exp((-1i.*(m-m0).*(phi-ph)) + (cos(ph-phi).*2.*r.*r)./(T1(j).^2));
fun = matlabFunction(IQ1,'Vars',[r,ph,phi]);
result_2 = (1/(4.*pi.*pi)).*abs(integral3(@(r,ph,phi)fun(r,ph,phi),0, R/2,0,2*pi,0,2*pi)) ;
Result2(j) = result_2
end
end
Result2
parfor j= 1:length(z)
for m=1:length(M)
for m0=1:length(M0)
Is = (Con1.*conj(Con1)).*I2.*conj(I2);
IQ1 =Is(j).*r.*exp((-2.*r.*r)./(T1(j)^2)).*exp((-1i.*(m-m0).*(phi-ph)) + (cos(ph-phi).*2.*r.*r)./(T1(j).^2));
fun = matlabFunction(IQ1,'Vars',[r,ph,phi]);
result =log2(N) + (1/N).*( (1/(4.*pi.*pi)).*abs(integral3(@(r,ph,phi)fun(r,ph,phi),0, R/2,0,2*pi,0,2*pi)) ).*log2(((1/(4.*pi.*pi)).*abs(integral3(@(r,ph,phi)fun(r,ph,phi),0, R/2,0,2*pi,0,2*pi)))./(Result2))
C(j)= result
end
end
end
C
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Accepted Answer
Walter Roberson
on 30 Jan 2024
Moved: Walter Roberson
on 30 Jan 2024
You have nested parfor loops, but each time you are overwriting the (j) entry
result =log2(N) + (1/N).*( (1/(4.*pi.*pi)).*abs(integral3(@(r,ph,phi)fun(r,ph,phi),0, R/2,0,2*pi,0,2*pi)) ).*log2(((1/(4.*pi.*pi)).*abs(integral3(@(r,ph,phi)fun(r,ph,phi),0, R/2,0,2*pi,0,2*pi)))./(Result2))
You are dividing by the vector Result2 so you get a vector result.
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More Answers (1)
Athira T Das
on 31 Jan 2024
1 Comment
Walter Roberson
on 31 Jan 2024
result_4 = result_3.*log2(result_3./Result2);
That is a matrix operation involving all of Result2, so it gives a matrix result.
Suggestion: divide by Result2(j)
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