How to store data of FOR LOOP iteration?

In the following code i want all the data of each iteration to be stored in P_new, and also B_xq, B_xq , B_xq repectively, but what i get is only the last one. What needs to be changed in my code?

k = convhull(data_coord); 

for i = 1:length(k)
    
v1_x = x_data(k(i,1));
v1_y = y_data(k(i,1));
v1_z = z_data(k(i,1));
v2_x = x_data(k(i,2));
v2_y = y_data(k(i,2));
v2_z = z_data(k(i,2));
v3_x = x_data(k(i,3));
v3_y = y_data(k(i,3));
v3_z = z_data(k(i,3));
p1 = [v1_x  v1_y  v1_z];
p2 = [v2_x  v2_y  v2_z];
p3 = [v3_x  v3_y  v3_z];
ps = [p1; p2; p3];
p12 = p2-p1;
p23 = p3-p2;
P = [p12; p23];
q = sqrt(rand(5, 1));
q = [q q.*rand(5, 1)];
P_new = q*P+p1;

F_Bx = scatteredInterpolant(data_coord, B_x,'nearest');
B_xq = F_Bx(P_new(:,1),P_new(:,2),P_new(:,3));

F_By = scatteredInterpolant(data_coord, B_y,'nearest');
B_yq = F_By(P_new(:,1),P_new(:,2),P_new(:,3));

F_Bz = scatteredInterpolant(data_coord, B_z,'nearest');
B_zq = F_Bz(P_new(:,1),P_new(:,2),P_new(:,3));

end

Answer 1

[Sudhakar Shinde]

You can use P_new(i) or P_new{i} to store loop result.

[Nima]

in case of P_new{i}, there is an error : Unable to perform assignment because brace indexing is not supported for variables of this type.

in case of P_new(i) : Unable to perform assignment because the left and right sides have a different number of elements.

[Sudhakar Shinde]

From above code looks like need to use:

P_new(i,:)
%or
P_new(:,i)

[Nima]

another error : Unable to perform assignment because the indices on the left side are not compatible with the size of the right side.

[Sudhakar Shinde]

Can you attach detailed inputs:

data_coord, x_data, y_data & z_data to reproduce issue.

[Nima]

data = csvread('20points3D.csv',5,0);
B_x = transpose(data([61:80]));
B_y = transpose(data([81:100]));
B_z = transpose(data([101:120]));

x_data = transpose(data([1:20]));
y_data = transpose(data([21:40]));
z_data = transpose(data([41:60]));
data_coord = [x_data,y_data,z_data];

[Sudhakar Shinde]

P_new is required for calculations, so use below syntax to store outcomes:

B_xq(:,i)

B_yq(:,i)

B_zq(:,i)

As above final outcome is your area of interest P_new need not to be saved in loop and use as it is written now.