col

Represents a column in a matrix.

Syntax

• col(A, n)

  • A is a matrix

  • n is a positive integer

The returned value is an lvalue.

Description

If A is a matrix and n is an integer between 1 and width(A) (inclusively), then col(A, n) represents the nth column of A; typewise this is a vector. col(A, n) is an lvalue, so it may be assigned to. The value assigned to it must be a vector of dimension height(A). If A is a real matrix, col(A, n) can only be assigned a real vector.

Examples

A ≔ ❨❨2, 1, −i❩, ❨1, 0, 2❩, ❨4, i, 2❩, ❨0, 1, −1❩❩

⎛ 2   1  −i⎞
⎜ 1   0   2⎟
⎜ 4   i   2⎟
⎝ 0   1  −1⎠

col(A, 1)

 ⎛2⎞
 ⎜1⎟
e⎜4⎟
 ⎝0⎠

col(A, 1) ≔ ❨0, 1, 2, 3❩

 ⎛0⎞
 ⎜1⎟
e⎜2⎟
 ⎝3⎠

A

⎛ 0   1  −i⎞
⎜ 1   0   2⎟
⎜ 2   i   2⎟
⎝ 3   1  −1⎠

See also

• cols

• row