pracma (version 1.1.6)

subspace: Angle between two subspaces

Description

Finds the angle between two subspaces.

Usage

subspace(A, B)

Arguments

A, B

Numeric matrices; vectors will be considered as column vectors. These matrices must have the same number or rows.

Value

• An angle in radians.

Details

Finds the angle between two subspaces specified by the columns of A and B.

References

Strang, G. (1998). Introduction to Linear Algebra. Wellesley-Cambridge Press.

See Also

orth

Examples

180 * subspace(c(1, 2), c(2, 1)) / pi  #=> 36.87
180 * subspace(c(0, 1), c(1, 2)) / pi  #=> 26.565

H <- 
Hadamard(8)
A <- H[, 2:4]
B <- H[, 5:8]
subspace(A, B)    #=> 1.5708 or pi/2, i.e. A and B are orthogonal