Built in color maps
| Chapter 22. Matrix graphs |

## Built in color maps

There are three types of built in color maps

1. Standard maps

   Includes rainbow spectrum and heat maps and combination of plain red-green-blue maps

2. Normalized center

   These maps have a white:ish center. This is mostly useful to visualize the spread from a center value

3. Continues

   The maps have one base color where the hue changes

In the color maps in the following section the black bars under some colors in the color map shows the discrete colors (the plateaus) that the color map is made up of. All colors in between two "barred" colors are linear interpolations.

The script that was used to generate these color maps can be found under the example directory as "`colormaps.php`".

### Standard maps

To show heat gradient map 0 is the standard color map. To highlight the min and max values (to get a high contrast) map 3 is a good choice. Map two is a standard "rainbow" spectrum from red all up to violet.

Figure 22.13. Standard color maps

### Normalized center

These maps have a neutral (white) center and feathers out to the min/max value at each end.

Figure 22.14. Centered color map

### Continues map

These maps changes continues from the min color to the max color.

Figure 22.15. Continues color map

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