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# brighten

Brighten or darken colormap

## Syntax

brighten(beta)
brighten(h,beta)
newmap = brighten(beta)
newmap = brighten(cmap,beta)

## Description

brighten(beta) increases or decreases the color intensities in a colormap by replacing the current colormap with a brighter or darker colormap of essentially the same colors. The modified colormap is brighter if 0 < beta < 1 and darker if -1 < beta < 0. brighten(beta), followed by brighten(-beta), where beta < 1, restores the original map.

brighten(h,beta) brightens all objects that are children of the figure having the handle h.

newmap = brighten(beta) returns a brighter or darker version of the current colormap without changing the display.

newmap = brighten(cmap,beta) returns a brighter or darker version of the colormap cmap without changing the display.

## Examples

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### Brighten Colormap

Display a surface plot of membrane.

```surf(membrane)
```

Brighten the colormap.

```beta = .7;
brighten(beta)
```

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### Algorithms

brighten raises values in the colormap to the power of gamma, where gamma is

$\gamma =\left\{\begin{array}{cc}1-\beta ,& \beta >0\\ \frac{1}{1+\beta },& \beta \le 0\end{array}$

brighten has no effect on graphics objects defined with true color.