https://github.com/cran/pracma
Revision 26e049d70b4a1c237987e260cba68f6a9413736c authored by Hans W. Borchers on 09 April 2019, 04:10:07 UTC, committed by cran-robot on 09 April 2019, 04:10:07 UTC
1 parent bf07673
Tip revision: 26e049d70b4a1c237987e260cba68f6a9413736c authored by Hans W. Borchers on 09 April 2019, 04:10:07 UTC
version 2.2.5
version 2.2.5
Tip revision: 26e049d
cart2sph.Rd
\name{cart2sph}
\alias{cart2sph}
\alias{sph2cart}
\alias{cart2pol}
\alias{pol2cart}
\title{
Coordinate Transformations
}
\description{
Transforms between cartesian, spherical, polar, and cylindrical coordinate
systems in two and three dimensions.
}
\usage{
cart2sph(xyz)
sph2cart(tpr)
cart2pol(xyz)
pol2cart(prz)
}
\arguments{
\item{xyz}{cartesian coordinates x, y, z as vector or matrix.}
\item{tpr}{spherical coordinates theta, phi, and r as vector or matrix.}
\item{prz}{polar coordinates phi, r or cylindrical coordinates phi, r, z
as vector or matrix.}
}
\details{
\code{cart2sph} returns spherical coordinates as (theta, phi, r), and
\code{sph2cart} expects them in this sequence.
\code{cart2pol} returns polar coordinates (phi, r) if \code{length(xyz)==2}
and cylindrical coordinates (phi, r, z) else. \code{pol2cart} needs them in
this sequence and length.
To go from cylindrical to cartesian coordinates, transform to cartesian
coordinates first --- or write your own function, see the examples.
All transformation functions are vectorized.
}
\value{
All functions return a (2- or 3-dimensional) vector representing a point
in the requested coordinate system, or a matrix with 2 or 3 named columns
where is row represents a point. The columns are named accordingly.
}
\note{
In Matlab these functions accept two or three variables and return two or
three values. In R it did not appear appropriate to return coordinates as
a list.
These functions should be vectorized in the sense that they accept will
accept matrices with number of rows or columns equal to 2 or 3.
}
\examples{
x <- 0.5*cos(pi/6); y <- 0.5*sin(pi/6); z <- sqrt(1 - x^2 - y^2)
(s <-cart2sph(c(x, y, z))) # 0.5235988 1.0471976 1.0000000
sph2cart(s) # 0.4330127 0.2500000 0.8660254
cart2pol(c(1,1)) # 0.7853982 1.4142136
cart2pol(c(1,1,0)) # 0.7853982 1.4142136 0.0000000
pol2cart(c(pi/2, 1)) # 6.123234e-17 1.000000e+00
pol2cart(c(pi/4, 1, 1)) # 0.7071068 0.7071068 1.0000000
## Transform spherical to cylindrical coordinates and vice versa
sph2cyl <- function(th.ph.r) cart2pol(sph2cart(th.ph.r))
cyl2sph <- function(phi.r.z) cart2sph(pol2cart(phi.r.z))
}
\keyword{ math }
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