# rowmult: Multiply Rows by Constants In matlib: Matrix Functions for Teaching and Learning Linear Algebra and Multivariate Statistics

## Description

Multiplies one or more rows of a matrix by constants. This corresponds to multiplying or dividing equations by constants.

## Usage

 `1` ```rowmult(x, row, mult) ```

## Arguments

 `x` a matrix, possibly consisting of the coefficient matrix, A, joined with a vector of constants, b. `row` index of one or more rows. `mult` row multiplier(s)

## Value

the matrix `x`, modified

`echelon`, `gaussianElimination`
Other elementary row operations: `rowadd`, `rowswap`
 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13``` ```A <- matrix(c(2, 1, -1, -3, -1, 2, -2, 1, 2), 3, 3, byrow=TRUE) b <- c(8, -11, -3) # using row operations to reduce below diagonal to 0 Ab <- cbind(A, b) (Ab <- rowadd(Ab, 1, 2, 3/2)) # row 2 <- row 2 + 3/2 row 1 (Ab <- rowadd(Ab, 1, 3, 1)) # row 3 <- row 3 + 1 row 1 (Ab <- rowadd(Ab, 2, 3, -4)) # multiply to make diagonals = 1 (Ab <- rowmult(Ab, 1:3, c(1/2, 2, -1))) # The matrix is now in triangular form ```