How to convert 1D matrix to 3D matrix with specific order.

I have a 1D matrix (1 by 6,000,000) of data. I want to reshape this to a three dimensional matrix that is 100 by 100 by 600. However, when I use the reshape function, the order of the numbers comes out incorrect.

For example: (12 numbers)

a=

 0.01

 0.02

 0.03

 0.04

 0.05

 0.06

 0.07

 0.08

 0.09

 0.10

 0.11

 0.12

I want b to be: (assume 2 by 2 by 3)

b(:,:,1)=

         0.01    0.07

         0.04    0.10

b(:,:,2)=

         0.02    0.08

         0.05    0.11

b(:,:,3)=

          0.03    0.09

          0.06    0.12

Basically, the order that I want is if the x axis had 2 points, y axis had 3 points, and z axis had 2 points, Point 1 would be (x1, y1, z1), Point 2 would be (x1, y1, z2), Point 3 would be (x2, y1, z1), Point 4 would be (x2,y1,z2), Point 5 would be (x1, y2, z1), Point 6 would be (x1, y2,z2), Point 7 would be (x2,y2,z1), Point 8 would be (x2,y2,z2) and on to Point 12.

What is the most efficient way to do this?

Thank you.

Answer 1

[Azzi Abdelmalek]

a=0.01:0.01:0.60
%you want a nxmxp matrix with:
n=3
m=4
p=5
out=permute(reshape(a,p,n,m),[2,3,1])

You can apply this to your case 2x2x3 matrice

a=0.01:0.01:0.12
n=2
m=2
p=3
out=permute(reshape(a,p,n,m),[2,3,1])

[Eric Jiang]

Thank you very much!

This was exactly what I was looking for.