getmatrix#

Purpose#

Gets a contiguous matrix from an N-dimensional array.

Format#

y = getmatrix(a, loc)#

Parameters:

a (N-dimensional array) – data
loc (Mx1 vector) – indices into the array to locate the matrix of interest where M equals N, N-1 or N-2.

Returns:

y (KxL or 1xL matrix or scalar) – where L is the size of the fastest moving dimension of the array and K is the size of the second fastest moving dimension.

Examples#

// Create the sequence 1, 2, 3...20
a = seqa(1, 1, 20);

/*
** Reshape the column vector 'a' into a 3x3x2 dimensional
** array
*/
a = areshape(a, 3|3|2);

// Extract the second 3x2 array
mat = getmatrix(a, 2);

After code above a is equal to:

Plane [1,.,.]

       1.0000000        2.0000000
       3.0000000        4.0000000
       5.0000000        6.0000000

Plane [2,.,.]

       7.0000000        8.0000000
       9.0000000        10.000000
       11.000000        12.000000

Plane [3,.,.]

       13.000000        14.000000
       15.000000        16.000000
       17.000000        18.000000

and mat is equal to:

0000000        8.0000000
0000000        10.000000
000000        12.000000

Remarks#

Inputting an Nx1 locator vector will return a scalar, an (N-1)x1 locator vector will return a 1xL matrix, and an (N-2)x1 locator vector will return a KxL matrix.