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# `psychopy.tools.coordinatetools`¶

Functions and classes related to coordinate system conversion

 `cart2pol`(x, y[, units]) Convert from cartesian to polar coordinates. `cart2sph`(z, y, x) Convert from cartesian coordinates (x,y,z) to spherical (elevation, azimuth, radius). `pol2cart`(theta, radius[, units]) Convert from polar to cartesian coordinates. `sph2cart`(*args) Convert from spherical coordinates (elevation, azimuth, radius) to cartesian (x,y,z).

## Function details¶

`psychopy.tools.coordinatetools.``cart2pol`(x, y, units='deg')

Convert from cartesian to polar coordinates.

Usage: theta, radius = pol2cart(x, y, units=’deg’)

units refers to the units (rad or deg) for theta that should be returned

`psychopy.tools.coordinatetools.``cart2sph`(z, y, x)

Convert from cartesian coordinates (x,y,z) to spherical (elevation, azimuth, radius). Output is in degrees.

usage:

array3xN[el,az,rad] = cart2sph(array3xN[x,y,z]) OR elevation, azimuth, radius = cart2sph(x,y,z)

If working in DKL space, z = Luminance, y = S and x = LM

`psychopy.tools.coordinatetools.``pol2cart`(theta, radius, units='deg')

Convert from polar to cartesian coordinates.

usage:

```x,y = pol2cart(theta, radius, units='deg')
```
`psychopy.tools.coordinatetools.``sph2cart`(*args)

Convert from spherical coordinates (elevation, azimuth, radius) to cartesian (x,y,z).

usage:
array3xN[x,y,z] = sph2cart(array3xN[el,az,rad]) OR x,y,z = sph2cart(elev, azim, radius)