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Scilab Help >> Elementary Functions > Matrix - shaping > matrix

matrix

reshapes an array with the same number and order of components

Syntax

y = matrix(v, m, n)
y = matrix(v, m1, m2, m3, ..)
y = matrix(v, [sizes])

Arguments

v

Any matricial container (regular matrix of any data type; cells array; structures array), of any number of dimensions (vector, matrix, hyperarray), with any sizes.

n, m, m1, m2, ..

positive integers: new expected sizes after reshaping. One of them may be set to -1.

sizes

vector of positive integers: new expected sizes

y

the reshaped array, with y(i)==v(i) and size(y,"*")==size(v,"*").

Description

For an array or hyperarray v with n x m entries, y = matrix(v, n, m) or y = matrix(v, [n,m]) transforms v into a n x m matrix, by stacking columnwise the entries of v.

Similarly, for an array or hyperarray v with m1 x m2 x m3 .. entries, y = matrix(v, m1, m2, m3,..) or y = matrix(v, [m1 m2 m3..]) transforms v into a hyperarray with m1 rows, m2 columns, m3 .. layers, ...etc.

In all cases, the linear order of components in y is the same as in v: For any 1 <= i <= size(v,"*"), y(i)=v(i).

If one of the sizes m or n or m1 etc.. is equal to -1, its actual value is automatically set such that the total number of components is unchanged.

  • y = v(:) is equivalent to matrix(v,-1, 1)
  • matrix() can be overloaded for any mlist() type, with a function named %<type>_matrix(v,s,..) with at least 2 input arguments.

Examples

With a regular matrix of decimal numbers:

a = [1 3 5 7 9 11; 2 4 6 8 10 12]
matrix(a, 4, 3)
matrix(a, [3 4])
matrix(a, 3, -1)
// into an hypermatrix:
matrix(a, 3, 2, 2)

With texts:

t = strsplit("a":"x",1:23)'
matrix(t,[3,8])
--> t = strsplit("a":"x",1:23)'
 t  =
!a  b  c  d  e  f  g  h  i  j  k  l  m  n  o  p  q  r  s  t  u  v  w  x  !

--> matrix(t,[3,8])
 ans  =
!a  d  g  j  m  p  s  v  !
!b  e  h  k  n  q  t  w  !
!c  f  i  l  o  r  u  x  !

With a cells hyperarray:

c = makecell([2,3,2], %t,%z, %i,"abc", list(%pi,"a"), int8(23),cos,sind,"àèìòù",corelib, 0.5, 1/%z^2)
rc = matrix(c, 3, 4)
rc(8)==c(8)
rc{8}.getshell
 c  =
(:,:,1)
  [1x1 boolean]  [1x1 polynomial]  [1x1 constant]
  [1x1 string ]  [    list      ]  [1x1 int8    ]
(:,:,2)
  [      1 fptr   ]  [      1 function]  [1x1 string]
  [        library]  [    1x1 constant]  [    r     ]

--> rc = matrix(c, 3, 4)
 rc  =
  [1x1 boolean   ]  [    list    ]  [      1 fptr    ]  [1x1 constant]
  [1x1 string    ]  [1x1 constant]  [        library ]  [1x1 string  ]
  [1x1 polynomial]  [1x1 int8    ]  [      1 function]  [    r       ]

--> rc(8)==c(8)
 ans  =
  T

--> rc{8}.getshell
 ans  =
 cmd

With a structures array:

clear s
s(3,6).r = %pi
matrix(s,2,9)
--> s(3,6).r = %pi
 s  =
  3x6 struct array with fields:
    r

--> matrix(s,2,9)
 ans  =
  2x9 struct array with fields:
    r

See also

  • colon (:) — Ranging operator. Addresses all elements along an array dimension or of a list.
  • resize_matrix — trim or/and extend (and cast) a matrix or hypermatrix
  • ndims — number of dimensions of an array
  • size — size of objects
  • extraction — matrix and list entry extraction
  • transposition — (') transpose operator, string delimiter
  • brackets [..] — Concatenation. Recipients of an assignment. Results of a function
  • matrices — Scilab objects, matrices in Scilab
  • hypermatrices — a Scilab object, N dimensional matrix in Scilab
  • makecell — Creates a cell array.
  • struct — create a struct
  • mlist — Scilab object, matrix oriented typed list definition
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Last updated:
Mon Feb 12 19:26:47 CET 2018