**GMT** programs read real-world coordinates and convert them to positions on a plot.
This is achieved by selecting one of several coordinate transformations or projections.
We distinguish between three sets of such conversions:

- Cartesian coordinate transformations
- Polar coordinate transformations
- Map coordinate transformations

The next chapter will be dedicated to **GMT** map projections in its entirety. Meanwhile, the present chapter
will summarize the properties of the Cartesian and Polar coordinate transformations available in **GMT**, list
which parameters define them, and demonstrate how they are used to create simple plot axes. We will mostly
be using * psbasemap* (and occasionally

- 5.1 Cartesian Transformations
- 5.1.1 Cartesian Linear Transformation (
**-Jx****-JX**) - 5.1.2 Cartesian Logarithmic projection
- 5.1.3 Cartesian Power projection

- 5.1.1 Cartesian Linear Transformation (
- 5.2 Linear Projection with Polar ()
Coordinates (
**-Jp****-JP**)