R/fDotProduct.R

In thecomeonman/POV: 3D transformations

#' Dot product between two vectors
#' @param v1, a matrix [x,y,z]
#' @param v2, a matrix [x,y,z]
#' @export
fDotProduct = function(v1, v2) {

    if ( any(class(v1) != 'matrix') ) {
        warning('Assuming vector of 3 reals has been passed as v1')
        v1 = matrix(v1, ncol = 3)
    }

    if ( any(class(v2) != 'matrix') ) {
        warning('Assuming vector of 3 reals has been passed as v2')
        v2 = matrix(v2, ncol = 3)
    }

    mDP = rowSums(cbind(
        ( v1[,1] * v2[,1] ),
        ( v1[,2] * v2[,2] ),
        ( v1[,3] * v2[,3] )
    ))

    mDP

}