Colormap: Colormap API

This module provides the Colormap object

Colormap class

class silx.gui.plot.Colormap.Colormap(name='gray', colors=None, normalization='linear', vmin=None, vmax=None)[source]

Bases: PyQt4.QtCore.QObject

Description of a colormap

Parameters:
  • name (str) – Name of the colormap
  • colors (tuple) – optional, custom colormap. Nx3 or Nx4 numpy array of RGB(A) colors, either uint8 or float in [0, 1]. If ‘name’ is None, then this array is used as the colormap.
  • normalization (str) – Normalization: ‘linear’ (default) or ‘log’
  • vmin (float) – Lower bound of the colormap or None for autoscale (default)
  • vmax (float) – Upper bounds of the colormap or None for autoscale (default)
LINEAR = 'linear'

constant for linear normalization

LOGARITHM = 'log'

constant for logarithmic normalization

NORMALIZATIONS = ('linear', 'log')

Tuple of managed normalizations

sigChanged

Signal emitted when the colormap has changed.

isAutoscale()[source]

Return True if both min and max are in autoscale mode

getName()[source]

Return the name of the colormap :rtype: str

getNColors(nbColors=None)[source]

Returns N colors computed by sampling the colormap regularly.

Parameters:nbColors (int or None) – The number of colors in the returned array or None for the default value. The default value is 256 for colormap with a name (see setName()) and it is the size of the LUT for colormap defined with setColormapLUT().
Returns:2D array of uint8 of shape (nbColors, 4)
Return type:numpy.ndarray
setName(name)[source]

Set the name of the colormap to use.

Parameters:name (str) – The name of the colormap. At least the following names are supported: ‘gray’, ‘reversed gray’, ‘temperature’, ‘red’, ‘green’, ‘blue’, ‘jet’, ‘viridis’, ‘magma’, ‘inferno’, ‘plasma’.
getColormapLUT()[source]

Return the list of colors for the colormap or None if not set

Returns:the list of colors for the colormap or None if not set
Return type:numpy.ndarray or None
setColormapLUT(colors)[source]

Set the colors of the colormap.

Parameters:colors (numpy.ndarray) – the colors of the LUT
getNormalization()[source]

Return the normalization of the colormap (‘log’ or ‘linear’)

Returns:the normalization of the colormap
Return type:str
setNormalization(norm)[source]

Set the norm (‘log’, ‘linear’)

Parameters:norm (str) – the norm to set
getVMin()[source]

Return the lower bound of the colormap

Returns:the lower bound of the colormap
Return type:float or None
setVMin(vmin)[source]

Set the minimal value of the colormap

Parameters:vmin (float) – Lower bound of the colormap or None for autoscale (default) value)
getVMax()[source]

Return the upper bounds of the colormap or None

Returns:the upper bounds of the colormap or None
Return type:float or None
setVMax(vmax)[source]

Set the maximal value of the colormap

Parameters:vmax (float) – Upper bounds of the colormap or None for autoscale (default)
isEditable()[source]

Return if the colormap is editable or not

Returns:editable state of the colormap :rtype: bool
setEditable(editable)[source]

Set the editable state of the colormap

Parameters:editable (bool) – is the colormap editable
getColormapRange(data=None)[source]

Return (vmin, vmax)

Returns:the tuple vmin, vmax fitting vmin, vmax, normalization and data if any given
Return type:tuple
setVRange(vmin, vmax)[source]

Set the bounds of the colormap

Parameters:
  • vmin – Lower bound of the colormap or None for autoscale (default)
  • vmax – Upper bounds of the colormap or None for autoscale (default)
copy()[source]

Return a copy of the Colormap.

Return type:silx.gui.plot.Colormap.Colormap
applyToData(data)[source]

Apply the colormap to the data

Parameters:data (numpy.ndarray) – The data to convert.
static getSupportedColormaps()[source]

Get the supported colormap names as a tuple of str.

The list should at least contain and start by: (‘gray’, ‘reversed gray’, ‘temperature’, ‘red’, ‘green’, ‘blue’) :rtype: tuple

restoreState(byteArray)[source]

Read the colormap state from a QByteArray.

Parameters:byteArray (qt.QByteArray) – Stream containing the state
Returns:True if the restoration sussseed
Return type:bool
saveState()[source]

Save state of the colomap into a QDataStream.

Return type:qt.QByteArray