Check reciprocal matrix — is.reciprocal • mapMCDA

Check whether a matrix is reciprocal. This is, whether the entrywise product of itself with its transpose (Hadamard product) is 1 for all its elements.

is.reciprocal(x)

Arguments

x: square numeric matrix or number

Value

logical

Examples

  Xf <- matrix(1:16, 4, 4)
  Xr <- Xf
  Xr[upper.tri(Xf)] <- 1/t(Xf)[upper.tri(Xf)]
  diag(Xr) <- 1
  mapMCDA:::is.reciprocal(Xf)  # FALSE
#> [1] FALSE
  mapMCDA:::is.reciprocal(Xr)  # TRUE
#> [1] TRUE