TRANSPOSE Function

Reference Guide > T Routines > TRANSPOSE Function

TRANSPOSE Function

Transposes the input array.

enabled.

note	This operation performs best when the system variable !CACHE accurately reflects cache sizes on the host machine.

Usage

result = TRANSPOSE(array)

Input Parameters

array—The array to be transposed. The input array can have any number of dimensions.

Returned Value

result—The transposed array.

Keywords

Dimension—A vector of two integers (n ≥ 0) designating the dimensions to transpose. Default: [0,1]

Discussion

TRANSPOSE is used to interchange two dimensions of an array, most commonly the rows and columns of a matrix. For vectors and co-vectors, TRANSPOSE can be used to change from one to the other, but it is more efficient to use REFORM for this purpose.

Example 1

a = INDGEN(2,3)

PM, a

; PV-WAVE prints the following:

;   0       2       4

;   1       3       5

PM, TRANSPOSE(a)

; PV-WAVE prints the following:

;   0       1

;   2       3

;   4       5

Example 2

OPENR, lun, !Dir + '/demo/gallery3/data/aerial_demo.img', /Get_lun

aerial_img = BYTARR(512,512)

READU, lun, aerial_img

FREE_LUN, lun

WINDOW, Xsize=512, Ysize=512, /Free, Title='Original Image'

TVSCL, aerial_img

WINDOW, Xsize=512, Ysize=512, /Free, Title='Transposed Image'

TVSCL, TRANSPOSE(aerial_img)

Transposed Image shows what an aerial image looks like before and after applying TRANSPOSE.

Figure 17-1: Transposed Image

Example 3

a = INDGEN(2, 4, 3)

PM, a

; PV-WAVE prints the following:

; 0       2       4       6

; 1       3       5       7

; 8      10      12      14

; 9      11      13      15

; 16      18      20      22

; 17      19      21      23

PM, TRANSPOSE(a, Dimension=[0,2])

; PV-WAVE prints the following:

; 0       2       4       6

; 8       10      12      14

; 16      18      20      22

; 1       3       5       7

; 9       11      13      15

; 17      19      21      23