Linear combination of matrix columns
This functionality does not run in MATLAB.
linalg::addCol(A, c1, c2, s1) linalg::addCol(A, c1, c2, s1, s2)
linalg::addCol(A, c1, c2, s1) adds s1 times column c1 to column c2, in the matrix A.
linalg::addCol(A, c1, c2, s) returns a copy of the matrix A in which column c2 of A is replaced by s col(A, c1) + col(A, c2).
linalg::addCol(A, c1, c2, s1, s2) returns a copy of the matrix A in which column c2 of A is replaced by s1 col(A, c1) + s2 col(A, c2).
The following defines a 3×3 matrix over the integers:
A := Dom::Matrix(Dom::Integer)( [[1, 2, 3], [4, 5, 6], [7, 8, 9]] )
We replace the 2nd column by - col(A, 1) + col(A, 2), i.e., we subtract the first column from the second:
linalg::addCol(A, 1, 2, -1)
The following defines a 2×3 matrix over the reals:
B := Dom::Matrix(Dom::Real)( [[sin(2), 0, 1], [1, PI, 0]] )
If s is an expression that does not represent a real number then an error message is reported. The following tries to replace the 1st column by x col(B, 3) + col(B, 1), where x is an identifier which cannot be converted to the component ring Dom::Real of B:
delete x: linalg::addCol(B, 3, 1, x)
Error: Cannot convert 'x'. [linalg::addCol]
If symbolic expressions are involved, then one may define matrices over a component ring created by Dom::ExpressionField. The following example defines a matrix over this default component ring:
delete a11, a12, a21, a22, x: C := matrix([[a11, a12], [a21, a22]])
We retry the input from the previous example:
linalg::addCol(C, 2, 1, x)
An m×n matrix of a domain of category Cat::Matrix
The column indices: positive integers less or equal to n
Expressions that can be converted to the component ring of A