resize_matrix
trim or/and extend (and cast) a matrix or hypermatrix
Syntax
resize_matrix // demo resMat = resize_matrix(mat, nbRows, nbCols) resMat = resize_matrix(mat, nbRows, nbCols, resType) resMat = resize_matrix(mat, nbRows, nbCols, resType, padding) resMat = resize_matrix(mat, nbRows, nbCols, "" , padding) resMat = resize_matrix(mat, newSizes) resMat = resize_matrix(mat, newSizes, resType) resMat = resize_matrix(mat, newSizes, resType, padding) resMat = resize_matrix(mat, newSizes, "" , padding)
Arguments
 mat
input matrix or hypermatrix. booleans, encoded integers, decimalencoded numbers (real or complex), polynomials, or text are supported.
 nbRows
new number of rows of the resized matrix. Exceeding rows are trimmed. Missing rows are added by padding. Setting
nbRows < 0
keeps the current number of rows. nbCols
new number of columns of the resized matrix. Exceeding columns are trimmed. Missing columns are added by padding. Setting
nbCols < 0
keeps the current number of columns. newSizes
vector specifying the new sizes along each dimension of
mat
. To keep a new size equal to the current one, just set it to 1.If the vector
newSizes
is shorter thansize(mat)
, it is padded with ones. Example: ifmat
withsize(mat)==[ 4 3 3 2]
is provided andnewSizes=[6 2]
is specified,newSizes = [6 2 1 1]
is considered.Conversely, if
newSizes
is longer thansize(mat)
, new dimensions are added tomat
and padded. Example: ifmat
such thatsize(mat)==[ 4 3 ]
is provided andnewSizes=[6 2 2]
is specified, the result will be an hypermatrix with 2 pages, the second one being fully padded.newSizes = [nbRows, nbCols]
may be used for a matrix. padding
optional scalar of same type as
mat
, specifying the content to set in elements created when the size along a dimension is increased. The default padding is done with0
(real or complex decimals, encoded integers, polynomials), or""
(text), or%F
(booleans).When
mat
andpadding
types do not match, scilab tries to convert thepadding
's oneFor polynomials, the varname of the padding is forced to the
mat
's one. resType
optional text word specifying the data type into which the resized matrix must be converted. "boolean", "constant", "string", "int8", "uint8", "int16", "uint16", "int32", "uint32", "int64", and "uint64" are supported.
Type conversion is supported neither for Polynomials nor for hypermatrix of text.
 resMat
resized (and converted) matrix or hypermatrix
Description
Creates a matrix of sizes [nbRows, nbCols]
or
newSizes
, or an hypermatrix of sizes newSizes
.
If for a dimension the new size is smaller than the initial one, the matrix is cropped.
If the size is increased, the matrix/hypermatrix is padded.
The number of dimensions can be increased. Conversely, Scilab automatically squeezes
highest dimensions with size kept or set to 1 (singletons).
The type of the result may be changed by specifying the resType
argument, with restrictions given above.
Examples
// Embedded examples, including with polynomials: resize_matrix // Resizing a numerical matrix: M = grand(4, 3, "uin", 9, 9) resize_matrix(M, 1, 5) // use 1 to keep a size unchanged resize_matrix(M, 2, 1) resize_matrix(M, 3, 4)
> M = grand(4, 3, "uin", 9, 9) M = 8. 5. 2. 9. 0. 1. 4. 1. 6. 5. 1. 8. > resize_matrix(M, 1, 5) // use 1 to keep a size unchanged ans = 8. 5. 2. 0. 0. 9. 0. 1. 0. 0. 4. 1. 6. 0. 0. 5. 1. 8. 0. 0. > resize_matrix(M, 2, 1) ans = 8. 5. 2. 9. 0. 1. > resize_matrix(M, 3, 4) ans = 8. 5. 2. 0. 9. 0. 1. 0. 4. 1. 6. 0.
resize_matrix(M, [3 4 2]) resize_matrix(M, [3 4 2], "", %i) resize_matrix(M, [3 4 2], "string", %i) // Matrix of text: myMatString = ["Scilab", "the"; "Open Source", "Scientific"; "Software", "Package"] resize_matrix( myMatString, 5, 3 ) // Equivalent syntax for new sizes: resize_matrix( myMatString, [5 3], "", "$" ) // With custom padding // Crops, pads and casts an hypermatrix: h = rand(2, 3, 2)*200 resize_matrix(h, [3 2 3], "int8") resize_matrix(h, [3 2 3], "int8", 1) // Custom padding r = resize_matrix(h, [3 2 ] , "" , 1) // Custom padding without type conversion size(r) // The last dimension has been squeezed // With Polynomials: x = poly(0, "x"); P = (1x)^grand(4, 2, "uin", 0, 3) resize_matrix(P, 3, 3) resize_matrix(P, [3 3 2]) resize_matrix(P, [3 3 2], "", %z) // => The padding's unknown is forced to the P's one // => Polynomials can't be converted
See also
History
Version  Description 
5.5.0 

6.0.1  The resType option is extended to the new
int64 and uint64 integer types. 
Report an issue  
<< pertrans  Matrix manipulation  squeeze >> 