R/itoxyz.R

In RPMG: Graphical User Interface (GUI) for Interactive R Analysis Sessions

`itoxyz` <-
  function(i, nx, ny, nz)
  {
    ##X## given a number index in  a vector, get the 3D pixel location   
    ##X## ###  itoxyz(24, 6, 6, 1)
    ##X## ###  itoxyz(24, 6, 6, 1)
    
    
    lentop <- nx * ny
    side <- (nx)
    nrem <- i%%lentop
   iz<- floor(i/lentop) + 1
    iz[nrem==0] <-  floor(i[nrem==0]/lentop )

    
   ## iz[nrem==0] <- i/lentop	
    nrem[nrem==0] <- lentop

    
    iy <- floor((nrem - 1)/side) + 1
    ix <- nrem - (iy - 1) * nx
    
    ix[ix==0]<- nx
    
    return(list(ix = ix, iy = iy, iz = iz))
    
}

`xyztoi`<-function(ix, iy,iz,nx, ny, nz)
    {
### this is the inverse of itoxyz
        lentop = nx * ny
        return(ix + nx * (iy - 1) + (iz - 1) * lentop)
    }