linalg::col
-- extract columns of a
matrixlinalg::col
(A, c)
extracts the
c-th column vector of the matrix A.
linalg::col(A, c)
linalg::col(A, c1..c2)
linalg::col(A, list)
A |
- | an m x n matrix of a domain of category
Cat::Matrix |
c |
- | the column index: a positive integer <= n |
c1..c2 |
- | a range of column indices (positive integers <= n) |
list |
- | a list of column indices (positive integers <= n) |
a single column vector or a list of column vectors; a column vector
is an m x 1 matrix of category Cat::Matrix(R)
, where R is
the component ring of A
.
linalg::row
, linalg::delCol
, linalg::delRow
, linalg::setCol
, linalg::setRow
linalg::col
(A, c1..c2)
returns a list of
column vectors whose indices are in the range c1..c2
. If
c2 < c1
then the empty list []
is
returned.linalg::col
(A, list)
returns a list of
column vectors whose indices are contained in list
(in the
same order).We define a matrix over Q:
>> A := Dom::Matrix(Dom::Rational)( [[1, 1/5, 2], [-3/2, 0, 5]] )
+- -+ | 1, 1/5, 2 | | | | -3/2, 0, 5 | +- -+
and illustrate the three different input formats for
linalg::col
:
>> linalg::col(A, 2)
+- -+ | 1/5 | | | | 0 | +- -+
>> linalg::col(A, [2, 1, 3])
-- +- -+ +- -+ +- -+ -- | | 1/5 | | 1 | | 2 | | | | |, | |, | | | | | 0 | | -3/2 | | 5 | | -- +- -+ +- -+ +- -+ --
>> linalg::col(A, 2..3)
-- +- -+ +- -+ -- | | 1/5 | | 2 | | | | |, | | | | | 0 | | 5 | | -- +- -+ +- -+ --