Add values to an existing sparse column in place

Adds value to the existing nonzero entries of column j at rows i. Only existing nonzeros are updated; no new nonzeros are created. add_assign_col_inplace_unsafe skips the input validation performed by add_assign_col_inplace. When validate = TRUE, the function checks that i is strictly increasing, in range, and contains no NA; that value contains no NA/NaN; and that the column pointer p is nondecreasing.

Usage

add_assign_col_inplace(x, i, j, value, validate = TRUE)

add_assign_col_inplace_unsafe(x, i, j, value)

Arguments

x

dgCMatrix to be assigned

i

rows to be assigned in strictly increasing order

j

single integer giving column to assign

value

numeric vector (same length as i) to increment rows i of column j of x

validate

logical scalar; if TRUE, validates that i is strictly increasing and within bounds

Value

value passed to x

Examples

if (requireNamespace("Matrix", quietly = TRUE)) {
  x <- Matrix::Matrix(0, nrow = 4, ncol = 2, sparse = TRUE)
  x[1, 1] <- 1
  x[3, 1] <- 2
  # value is the same length as i
  add_assign_col_inplace(x, i = c(1L, 3L), j = 1L, value = c(10, -5))
}
#> 4 x 2 sparse Matrix of class "dgCMatrix"
#>          
#> [1,] 11 .
#> [2,]  . .
#> [3,] -3 .
#> [4,]  . .