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Triangular_solve

Usage

torch_triangular_solve(
  self,
  A,
  upper = TRUE,
  transpose = FALSE,
  unitriangular = FALSE
)

Arguments

self

(Tensor) multiple right-hand sides of size \((*, m, k)\) where \(*\) is zero of more batch dimensions (\(b\))

A

(Tensor) the input triangular coefficient matrix of size \((*, m, m)\) where \(*\) is zero or more batch dimensions

upper

(bool, optional) whether to solve the upper-triangular system of equations (default) or the lower-triangular system of equations. Default: TRUE.

transpose

(bool, optional) whether \(A\) should be transposed before being sent into the solver. Default: FALSE.

unitriangular

(bool, optional) whether \(A\) is unit triangular. If TRUE, the diagonal elements of \(A\) are assumed to be 1 and not referenced from \(A\). Default: FALSE.

triangular_solve(input, A, upper=TRUE, transpose=False, unitriangular=False) -> (Tensor, Tensor)

Solves a system of equations with a triangular coefficient matrix \(A\) and multiple right-hand sides \(b\).

In particular, solves \(AX = b\) and assumes \(A\) is upper-triangular with the default keyword arguments.

torch_triangular_solve(b, A) can take in 2D inputs b, A or inputs that are batches of 2D matrices. If the inputs are batches, then returns batched outputs X

Examples

if (torch_is_installed()) {

A = torch_randn(c(2, 2))$triu()
A
b = torch_randn(c(2, 3))
b
torch_triangular_solve(b, A)
}
#> [[1]]
#> torch_tensor
#> -2.0220 -2.1697  0.2369
#>  0.5612 -0.8687  0.3310
#> [ CPUFloatType{2,3} ]
#> 
#> [[2]]
#> torch_tensor
#>  0.5262  0.6967
#>  0.0000  0.7233
#> [ CPUFloatType{2,2} ]
#>