Choose subsets into arrays

There are several ways that you can access elements of a multi-dimensional array in GAUSS. I'm not certain that I understand enough context about your program and how you think about the data to give you the answer that you are looking for.

However, if you will only want to select a single index or all elements of a particular index it may be helpful to know that when you specify an index as zero, it acts the same as . and selects all elements.

For example:

// Create an example array
X = areshape(seqa(1.1, 1, 24), 2|3|4);

print X;

will print the full array, X.

Plane [1,.,.] 

     1.1      2.1      3.1      4.1 
     5.1      6.1      7.1      8.1 
     9.1     10.1     11.1     12.1 

Plane [2,.,.] 

    13.1     14.1     15.1     16.1 
    17.1     18.1     19.1     20.1 
    21.1     22.1     23.1     24.1

As you know you can access individual elements like this:

a = 2;
b = 1;
c = 3;

print X[a,b,c];

15.1

Setting an index equal to zero will select the entire range:

a = 2;
b = 1;
c = 0;

// Print the entire first row of the second hypercube
print X[a,b,c];

Plane [1,.,.] 
    13.1     14.1     15.1     16.1 

a = 0;
b = 1;
c = 0;

// Print the entire first row of both hypercubes
print X[a,b,c];

Plane [1,.,.] 
     1.1      2.1      3.1      4.1 

Plane [2,.,.] 
    13.1     14.1     15.1     16.1 

Does that answer your question, or are you looking for something else?

Thank you! That's exactly what I was looking, in your example, you did that:

I didn't know that this is equivalent to print X[.,1,.];