# Legacy Document

Important: The information in this document is obsolete and should not be used for new development.

Inside Macintosh: QuickDraw GX Environment and Utilities /
Chapter 8 - QuickDraw GX Mathematics / QuickDraw GX Mathematics Reference
Mathematical Functions / Cartesian and Polar Coordinate Point Conversions

### PolarToPoint

You can use the `PolarToPoint` function to convert a point in polar coordinates to the identical point in Cartesian coordinates.

```gxPoint *PolarToPoint(const gxPolar *ra, gxPoint *xy);
```
`ra`
A pointer to the point in polar coordinates.
`xy`
A pointer to the destination of the resulting point in Cartesian coordinates.
function result
A pointer to the converted point (also a pointer to the `xy parameter).`
##### DESCRIPTION
The `PolarToPoint` function converts the polar coordinate point (r, a) to the identical Cartesian coordinate point (x, y). The parameters of the `PolarToPoint` function are the `gxPolar` structure pointer `ra` and a `gxPoint` structure pointer `xy`.

If both pointers point to the same location, the source `gxPolar` structure will be converted to a `gxPoint` structure and will replace the `gxPolar` structure.

The `gxPolar` structure is described in the section "Constants and Data Types" beginning on page 8-35. Polar coordinate to Cartesian coordinate conversions are discussed in the section "Cartesian and Polar Coordinate Conversion" beginning on page 8-10. The `PointToPolar` function converts a point in Cartesian coordinates to the identical point in polar coordinates. The `PointToPolar` function is described next.