# How to add another coloumn to a matrix that update at every iteration

3 次查看（过去 30 天）
riki 2023-5-29

Hello, I'm trying to write a code that generate different functions with a certain weight. I wrote the first part thanks to @Andres but now I'm trying to do another thing. I would like to add a sixth coloumn to my matrix as I did that associate a certain solid_fraction to every p1,p2,p3 values given by the first 2 "for loop". The solid_fraction is given by M that it's a function of b,errore and all the 3 weights p1,p2,p3.
So that, for:
• p1=0; p2=0; p3=1; b=0; errore=0.4; solid_fraction=0.1060
• p1=0; p2=0; p3=1; b=0; errore=0.7; solid_fraction=0.1866
• ...
• p1=0; p2=0.25; p3=0.75; b=0; errore=0.4; solid_fraction=...
and so on.
The code is running but I can't got past Aix=25 (while I have 360 row to compute). pMin = 0;
pInc = 0.25;
pMax = 1;
pSomma = 1;
b = 0:0.4:2;
errore = 0.4:0.3:1.5;
pN = (pMax-pMin)/pInc+1;
bN = numel(b);
eN = numel(errore);
pNumCom = (pN)*(pN-1)/2;
beNumCombP = bN*eN;
bE = [reshape(repmat(b, [eN, 1]), [beNumCombP, 1]),repmat(errore(:), [bN, 1])];
A = zeros(pNumCom*beNumCombP,6);
k = 0;
for p1 = pMin:pInc:pMax
for p2 = pMin:pInc:(1-p1)
p3 = pSomma-p1-p2;
P = repmat([p1, p2, p3], [beNumCombP, 1]);
A(k+1 : k+beNumCombP, :) = [P, bE,zeros(24,1)];
k = k + beNumCombP;
end
end
%%
!rm simulated_CT/*.*
%number of unit cells
c= 1;
%b is proportional to porosity
%number of pixels in each direction
n= 101;
%threshold
%preparazione della matrice
clear M
M=zeros((n-1),(n-1),(n-1));
solid_fraction=zeros(24,1);
%%%s,t,u parameters to induce anisotropy
s=1.;
t=1.;
u=1.;
%create the folder for the simulated CT images
mkdir('Hybrid_Stack');
Aix=1;
idx=1
while Aix<=360
for p1 = pMin:pInc:pMax
for p2 = pMin:pInc:(1-p1)
p3 = pSomma-p1-p2;
while idx<=6
iex=1;
while iex<=4
for z1=1:(n-1)
for y1=1:(n-1)
for x1=1:(n-1)
x = s*x1;
y = t*y1;
z = u*z1;
f1(x1,y1,z1)= cos(2*pi*x*c/n)*cos(2*pi*y*c/n)*cos(2*pi*z*c/n)-sin(2*pi*x*c/n)*sin(2*pi*y*c/n)*sin(2*pi*z*c/n)+b(idx); %Diamante
f2(x1,y1,z1)= 2*cos(2*pi*x*c/n)*cos(2*pi*y*c/n)+2*cos(2*pi*y*c/n)*cos(2*pi*z*c/n)+2*cos(2*pi*z*c/n)*cos(2*pi*x*c/n)-cos(4*pi*x*c/n)-cos(4*pi*y*c/n)-cos(4*pi*z*c/n)+b(idx); %IWP
f3(x1,y1,z1)= cos(2*pi*x*c/n)+cos(2*pi*y*c/n)+cos(2*pi*z*c/n)+b(idx);%Giroide
fh(x1,y1,z1)=p1*f1(x1,y1,z1)+p2*f3(x1,y1,z1)+p3*f2(x1,y1,z1); %% here select the geometry you want f1,f2,f3
f(x1,y1,z1)=fh(x1,y1,z1);
if f(x1,y1,z1)<errore(iex) && f(x1,y1,z1)>(-1*errore(iex))
M(x1,y1,z1)=1;
M_q(x1,y1)=M(x1,y1,z1);
else
M(x1,y1,z1)=0;
M_q(x1,y1)=M(x1,y1,z1);
end
end
end
clc
progress=100*z1/n;
% % filename = sprintf('image_%d.bmp', z1);
% % imwrite(M_q,filename); %creazione immagine
% % movefile(filename, 'Hybrid_stack');
end
solid_fraction(Aix) = sum(sum(sum(M)))/(n-1)^3;
A(Aix,6)=solid_fraction(Aix);
iex=iex+1;
Aix=Aix+1
end
idx=idx+1
end
end
end
end

### 回答（1 个）

Dinesh 2023-6-5
Hi Riccardo!
I tried reproducing the issue on my side. I found that there is a problem in the code. After variable 'idx' becomes '7' we do not go into the while loop idx <= 6, thus we will not update the 'Aix' variable. Thus, Aix variable only updates for 25 times after that 'idx' becomes 7 and we are stuck in an infinite loop. This is the issue why the code is not working.
About how to add a column to a matrix you can simply.
A=reshape(1:16,4,4)
A = 4×4
1 5 9 13 2 6 10 14 3 7 11 15 4 8 12 16
B=(17:20)'
B = 4×1
17 18 19 20
A = [A B]
A = 4×5
1 5 9 13 17 2 6 10 14 18 3 7 11 15 19 4 8 12 16 20
Refer this MATLAB documentation for more details on reshape.
Hope this helps!
Thank you.

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