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math.matrices: Add a diagonal-matrix word that makes an nxn matrix from a sequence. 

Optimize identity-matrix word -- 2-3x faster using diagonal-matrix.
Add an eye word that makes an mxn diagonal matrix with a diagonal offset by k.
db4
Doug Coleman 2012-05-04 11:23:38 -07:00
parent cbf022454b
commit 6f3fe950a7
2 changed files with 80 additions and 4 deletions
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74
basis/math/matrices/matrices-tests.factor
View File

@ -7,14 +7,84 @@ USING: math.matrices math.vectors tools.test math ;
3 1 zero-matrix
] unit-test
[
{
{ { 1 0 0 }
{ 0 1 0 }
{ 0 0 1 } }
] [
} [
3 identity-matrix
] unit-test
{
{ { 1 0 0 }
{ 0 2 0 }
{ 0 0 3 } }
} [
{ 1 2 3 } diagonal-matrix
] unit-test
{
{
{ 1 0 0 }
{ 0 1 0 }
{ 0 0 1 }
}
} [
3 3 0 eye
] unit-test
{
{
{ 0 1 0 }
{ 0 0 1 }
{ 0 0 0 }
}
} [
3 3 1 eye
] unit-test
{
{
{ 0 0 0 }
{ 1 0 0 }
{ 0 1 0 }
}
} [
3 3 -1 eye
] unit-test
{
{
{ 1 0 0 0 }
{ 0 1 0 0 }
{ 0 0 1 0 }
}
} [
3 4 0 eye
] unit-test
{
{
{ 0 1 0 }
{ 0 0 1 }
{ 0 0 0 }
{ 0 0 0 }
}
} [
4 3 1 eye
] unit-test
{
{
{ 0 0 0 }
{ 1 0 0 }
{ 0 1 0 }
{ 0 0 1 }
}
} [
4 3 -1 eye
] unit-test
[
{ { 1 0 4 }
{ 0 7 0 }

10
basis/math/matrices/matrices.factor
View File

@ -9,9 +9,15 @@ IN: math.matrices
: zero-matrix ( m n -- matrix )
'[ _ 0 <array> ] replicate ;
: diagonal-matrix ( diagonal-seq -- matrix )
dup length dup zero-matrix
[ '[ dup _ nth set-nth ] each-index ] keep ; inline
: identity-matrix ( n -- matrix )
#! Make a nxn identity matrix.
iota dup [ = 1 0 ? ] cartesian-map ;
1 <repetition> diagonal-matrix ; inline
: eye ( m n k -- matrix )
[ [ iota ] bi@ ] dip neg '[ _ + = 1 0 ? ] cartesian-map ;
:: rotation-matrix3 ( axis theta -- matrix )
theta cos :> c