MATLAB Answers

Finding index location in volume?

7 views (last 30 days)
For instance, I have
x = 2000:0.5:2004; y = 45000:0.3:45009; z = 10:0.2:12;
which are axes of a volume, x has length of 9, y has 31 and z has 11.
Now a volume filled of nan values and given by;
C = rand(9,31,11)*nan;
I want to fill this volume with values when new values come up, it will have x, y, z and the corresponding value. So, I need to find the closest index location and fill the value there. E.g.
x =2002.13, y = 45006.811, z = 11.36 have value of 10000 so i want to fill the corresponding C(x,y,z) = 10000;
here I need to find the index for x = 2002, y = 45006.9, z = 11.4 and fill the value 10000 there in C.
how can I use the values converted to closed index in the volume. Thanks

  0 Comments

Sign in to comment.

Accepted Answer

Andrei Bobrov
Andrei Bobrov on 16 Sep 2019
x = 2000:0.5:2004;
y = 45000:0.3:45009;
z = 10:0.2:12;
x0 = 2002.13;
y0 = 45006.811;
z0 = 11.36;
C = nan(9,31,11);
C0 = 1000;
[~,ii] = min(abs(x - x0));
[~,jj] = min(abs(y - y0));
[~,k] = min(abs(z - z0));
C(ii,jj,k) = C0;

  1 Comment

Syed Abdul Salam
Syed Abdul Salam on 16 Sep 2019
work perfectly. Thanks

Sign in to comment.

More Answers (1)

Nicolas B.
Nicolas B. on 16 Sep 2019
Hi,
for your case, I would write your code like that:
x = 2000:0.5:2004; y = 45000:0.3:45009; z = 10:0.2:12;
% no need to use rand() to generate a table of NaN and it's more flexible with automatic size
C = NaN(length(x), length(y), length(z));
% your points
pts = [2002.13, 45006.811, 11.36];
% your coordinates
[~, xc] = min(abs(x - pts(1)));
[~, yc] = min(abs(y - pts(2)));
[~, zc] = min(abs(z - pts(3)));
% your value
C(xc, yc, zc) = my_value;
Do it help you?

  1 Comment

Syed Abdul Salam
Syed Abdul Salam on 16 Sep 2019
Yes, thank you. Both works perfectly.

Sign in to comment.

Products


Release

R2019a