Converting a 2d vector to a 4d vector

In a machine learning task, I need a 4d single type data to fed for training. But my data is in a 2d format. Would you please show me how to do this conversion.

Input:

for data of 28th row,

val(28,1)=1.5

val(28,2)=2.7

output:

val(:,:,1,28)=1.5

val(:,:,2,28)=2.7

I m looking for your advice in this regard.

Thanks,

Answer 1

[ANKUR KUMAR]

Let's take a random data A

A=randi(10,30,2);

Use permute to change into 4D

B=permute(A,[3,4,2,1]);

Now, B(:,:,2,24) and A(24,2) are same.

>> B(:,:,2,24)==A(24,2)

ans =

  logical

   1

[Basu Sau]

hi Ankur. would u pls explain the parameters u pass inside permute()?

[ANKUR KUMAR]

First input of permute is the data itself.

Second input is in the row matrix which contains the sequence of dimension you wish to put it.

For example, in B, we have stored first the fourth dimension, then the thrid dimension, followed by second and first.

If we write,

B=permute(A,[3,4,1,2]);

then

>> B(:,:,24,2)==A(24,2)

ans =

  logical

   1

SIMPLE EXAMPLE

>> A=magic(5)


A =

    17    24     1     8    15
    23     5     7    14    16
     4     6    13    20    22
    10    12    19    21     3
    11    18    25     2     9

>> permute (A,[2,1])

ans =

    17    23     4    10    11
    24     5     6    12    18
     1     7    13    19    25
     8    14    20    21     2
    15    16    22     3     9

Permute simply changes the dimension as per your input in purmute command.

[Basu Sau]

thanks ankur for a such explainatory comment

Answer 2

[madhan ravi]

Aternatively:

[m,n]=size(val);
Val=reshape(val.',1,1,n,m)