Conversion of C++ code to matlab code

Question

Venkat Raman 2020-1-14

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/500176-conversion-of-c-code-to-matlab-code

评论： Walter Roberson 2021-1-28

I've a C++ code to be converted to MATLAB script. Following is the code. Please assist in the conversion process. I've tried my part in conversion which I've attached

#include <iostream>
#include <math>
#include <complex>
#include <bits/stdc++.h>
#include <bits>
using namespace std;
void main()
{
const k=10;
const Rmn=12;
float phi=0;
float theta=90;
float phimn=14;
float thetamn=16;
int q=34;
const dx=23;
const dy=25;
int m,n;
cout<<"Enter the value of M"
cin>>m
cout<<"Enter the value of N"
cin>>n
int FinalAF=0;
for(int i=-m+1;i<=m;i++)
{
    for(int j=-n+1;j<=n;j++)
    {
       
        // e1=sin(-1*k*Rmn)+jcos(-1*k*Rmn)
        // e2=cos(phimn)+jsin(phimn)
       
        complex<double> compl1(0,-1*k*Rmn);
        complex<double> compl2(0,phimn);
        Inter=exp(compl1)*exp(compl2)/Rmn;
        Imn=Inter*cos(thetamn)^q;
       
        float xmn=(m-0.5)*dx;
        float ymn=(n-0.5)*dy;
       
        string rmn = to_string(xmn)+"x"+to_string(ymn)+"y"
      
        string rc = to_string(sin(theta)*cos(phi))+"x"+to_string(sin(theta)*cos(phi))+"y"+to_string(sin(theta)*cos(phi))+"z"
       
        complex<double> compl3(0, rmn*rc*k);
        AF=Imn*exp(compl3);
       
        FinalAF=FinalAF+AF;
         
    }
}
int Etheta = FinalAF*cos(theta);   
}
% The code that I tried converting from C++ to MATLAB
%k=10;
%rmn=12;
%phi=0;
%theta=90;
%thetamn=16;
%phimn=14;
%q=34;
%dx=23;
f=input('Enter the frequency in GHz');
rmn=input('Enter the distance form feed phase center to “mnth” element');
phimn=input('Enter the phase provided by the mnth element of microstrip reflectarray array');
q=input('Enter q for evaluating the cosine power radiation pattern');
epsilonr=2.2;
c = 3*1e8;
lambda0 = c/(f*1e9);
lambdag = lambda0/sqrt(epsilonr);
dx = lambdag/2;
k = 2*pi/lambda0;
M=input('Enter the number of rows');
N=input('Enter the number of columns');
string r = string(sin(theta)*cos(phi))+"x"+ string(sin(theta)*cos(phi))+"y"+ string(sin(theta)*cos(phi))+"z";
for m= -M+1:M
    for n= -N+1:N
        g=phimn-k*rmn;
        Imn=(exp(1i*g)*(cos(phimn)^q))/rmn;
    end
end
for m = -(M+1):M
    for n = -(N+1):N
AF = Imn*exp(1i*(rmn.*r)*k); 
% .* = dot product of rmn vector and r vector
    end
end
% let radiation pattern be E
for m = -(M+1):M
    for n = -(N+1):N
		E = AF*cos(phimn);
    end
end

6 个评论
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Walter Roberson 2020-1-14

You are trying to multiply STRINGS. You are not creating two three-D vectors and multiplying them: you are calculating the numeric portions of the vectors and converting them to text and adding in the characters 'x' and 'y' and 'z' in appropriate places, and then you are trying to multiply the text !

Guillaume 2020-1-14

编辑：Guillaume 2020-1-14

edit: I need my eyes tested, there's indeed a multiplication between strings in the C++ code which is completely meaningless. The C++ code couldn't have worked.

If I were given the task to convert code from one language to matlab, I would do it like this:

Understand what the code does
Write down the algorithm/equation implemented by said code
throw away that code and never look at it again
implement the algorithm/equation from step 2 in matlab

I would certainly not attempt to convert the code line by line. Attempting to write matlab code as if it was C++ is going to lead to very poor code.

As it appear you already have the equations, I would start from there and forget about the C++ code.

The equations can be implemented very easily in matlab without any loop. This will make it much easier to read as well. However, it's not clear to me why

has a vector arrow above it nor what

,

, and

are.

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Answer 1

Bhaskar R 2020-1-14

2
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/500176-conversion-of-c-code-to-matlab-code#answer_409999

在 MATLAB Online 中打开

You have not used loop iteration varibales in C++ code?, anyway the plane conversion of your code is

% using namespace std;
% void main()
% {
% const k=10;
k = 10;
% const Rmn=12;
Rmn=12;
% float phi=0;
phi=0;
% float theta=90;
theta=90;
% float phimn=14;
phimn=14;
% float thetamn=16;
thetamn=16;
% int q=34;
q=34;
% const dx=23;
dx=23;
% const dy=25;
dy=25;
% int m,n;
% cout<<"Enter the value of M"
% cin>>m
m = input('Enter the value of M : ');
% cout<<"Enter the value of N"
% cin>>n
n = input('Enter the value of N : ');
% int FinalAF=0;
FinalAF=0;
% for(int i=-m+1;i<=m;i++)
% {
for ii = -m+1:m
    %     for(int j=-n+1;j<=n;j++)
    %     {
    for jj = -n+1:n
        %  // e1=sin(-1*k*Rmn)+jcos(-1*k*Rmn)
        % // e2=cos(phimn)+jsin(phimn)
        % complex<double> compl1(0,-1*k*Rmn);
        compl1 = 0+(-1*k*Rmn)*1i;
        % complex<double> compl2(0,phimn);
        compl2 = 0+(phimn)*1i;      
        %Inter=exp(compl1)*exp(compl2)/Rmn;
        Inter = exp(compl1)*exp(compl2)/Rmn;
        % Imn=Inter*cos(thetamn)^q;
        Imn=Inter*cos(thetamn)^q;
        % float xmn=(m-0.5)*dx;
        xmn=(m-0.5)*dx;
        %         float ymn=(n-0.5)*dy;
        ymn=(n-0.5)*dy;
        %  string rmn = to_string(xmn)+"x"+to_string(ymn)+"y"
        rmn = [num2str(xmn), 'x', num2str(ymn), 'y'];
        % string rc = to_string(sin(theta)*cos(phi))+"x"+to_string(sin(theta)*cos(phi))+"y"+to_string(sin(theta)*cos(phi))+"z"
        rc = [num2str(sin(theta)*cos(phi)), 'x',...
            num2str(sin(theta)*cos(phi)), 'y', num2str(sin(theta)*cos(phi)), 'z'];
        %  complex<double> compl3(0, rmn*rc*k);
        compl3 = 0+ (rmn*rc*k)*1i;
        %AF=Imn*exp(compl3);
        AF=Imn*exp(compl3);
        % FinalAF=FinalAF+AF;
        FinalAF=FinalAF+AF;
    end
end
% int Etheta = FinalAF*cos(theta);
Etheta = FinalAF*cos(theta);

3 个评论
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Walter Roberson 2020-1-14

Which variable is to be on the x axes? Which variable is to be on the y axes? Which variable is to be on the z axes?

Venkat Raman 2020-1-14

The electric field which is a function of theta, phi and the distance vector is along the z axis, phi is along x axis and theta along y axis. phi and theta are measured in degrees while E field is measured in V/m

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