<matrix-by-indices> ( ... m n quot: ( ... m' n' -- ... elt ) -- ... matrix )
Matrix operations

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Vocabulary
math.matrices

Inputs

m	an integer
n	an integer
quot	a quotation with stack effect ( ... m' n' -- ... elt )

Outputs

matrix

a matrix

Word description
Creates an m x n matrix using elements given by quot . This word differs from <matrix-by> in that the indices are placed on the stack (in the same order) before quot runs. The output of the quotation will be the element at the given position in the matrix.

Notes
The following are equivalent:

m n [ 2drop foo ] <matrix-by-indices>

m n [ foo ] <matrix-by>

Examples

USING: math math.matrices prettyprint ; 3 4 [ * ] <matrix-by-indices> .
{ { 0 0 0 0 } { 0 1 2 3 } { 0 2 4 6 } }

Definition

USING: kernel sequences ;

IN: math.matrices

: <matrix-by-indices>
    ( ... m n quot: ( ... m' n' -- ... elt ) -- ... matrix )
    [ [ <iota> ] bi@ ] dip cartesian-map ; inline