R/sph.to.car.R

In AngusWright/LAMBDAR: Measure galaxy fluxes from an arbitrary FITS image using input aperture locations and dimensions

sph.to.car<-
function (long, lat, radius = 1, deg = TRUE)
{
  if (is.matrix(long) || is.data.frame(long)) {
    if (ncol(long) == 1) {
      long = long[, 1]
    }
    else if (ncol(long) == 2) {
      lat = long[, 2]
      long = long[, 1]
    }
    else if (ncol(long) == 3) {
      radius = long[, 3]
      lat = long[, 2]
      long = long[, 1]
    }
  }
  if (missing(long) | missing(lat)) {
    stop("Missing full spherical 3D input data.")
  }
  if (deg) {
    long = long * pi/180
    lat = lat * pi/180
  }
  return = cbind(x = radius * cos(long) * cos(lat), y = radius *
      sin(long) * cos(lat), z = radius * sin(lat))
}