251 lines
9.5 KiB
Python
251 lines
9.5 KiB
Python
import numpy as np
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from .Qt import QtGui, QtCore
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class ColorMap(object):
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"""
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A ColorMap defines a relationship between a scalar value and a range of colors.
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ColorMaps are commonly used for false-coloring monochromatic images, coloring
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scatter-plot points, and coloring surface plots by height.
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Each color map is defined by a set of colors, each corresponding to a
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particular scalar value. For example:
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| 0.0 -> black
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| 0.2 -> red
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| 0.6 -> yellow
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| 1.0 -> white
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The colors for intermediate values are determined by interpolating between
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the two nearest colors in either RGB or HSV color space.
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To provide user-defined color mappings, see :class:`GradientWidget <pyqtgraph.GradientWidget>`.
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"""
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## color interpolation modes
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RGB = 1
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HSV_POS = 2
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HSV_NEG = 3
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## boundary modes
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CLIP = 1
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REPEAT = 2
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MIRROR = 3
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## return types
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BYTE = 1
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FLOAT = 2
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QCOLOR = 3
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enumMap = {
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'rgb': RGB,
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'hsv+': HSV_POS,
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'hsv-': HSV_NEG,
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'clip': CLIP,
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'repeat': REPEAT,
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'mirror': MIRROR,
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'byte': BYTE,
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'float': FLOAT,
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'qcolor': QCOLOR,
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}
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def __init__(self, pos, color, mode=None):
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"""
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=============== ==============================================================
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**Arguments:**
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pos Array of positions where each color is defined
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color Array of RGBA colors.
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Integer data types are interpreted as 0-255; float data types
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are interpreted as 0.0-1.0
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mode Array of color modes (ColorMap.RGB, HSV_POS, or HSV_NEG)
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indicating the color space that should be used when
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interpolating between stops. Note that the last mode value is
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ignored. By default, the mode is entirely RGB.
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=============== ==============================================================
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"""
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self.pos = np.array(pos)
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self.color = np.array(color)
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if mode is None:
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mode = np.ones(len(pos))
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self.mode = mode
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self.stopsCache = {}
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def map(self, data, mode='byte'):
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"""
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Return an array of colors corresponding to the values in *data*.
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Data must be either a scalar position or an array (any shape) of positions.
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The *mode* argument determines the type of data returned:
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=========== ===============================================================
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byte (default) Values are returned as 0-255 unsigned bytes.
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float Values are returned as 0.0-1.0 floats.
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qcolor Values are returned as an array of QColor objects.
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=========== ===============================================================
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"""
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if isinstance(mode, basestring):
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mode = self.enumMap[mode.lower()]
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if mode == self.QCOLOR:
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pos, color = self.getStops(self.BYTE)
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else:
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pos, color = self.getStops(mode)
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# don't need this--np.interp takes care of it.
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#data = np.clip(data, pos.min(), pos.max())
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# Interpolate
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# TODO: is griddata faster?
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# interp = scipy.interpolate.griddata(pos, color, data)
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if np.isscalar(data):
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interp = np.empty((color.shape[1],), dtype=color.dtype)
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else:
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if not isinstance(data, np.ndarray):
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data = np.array(data)
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interp = np.empty(data.shape + (color.shape[1],), dtype=color.dtype)
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for i in range(color.shape[1]):
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interp[...,i] = np.interp(data, pos, color[:,i])
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# Convert to QColor if requested
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if mode == self.QCOLOR:
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if np.isscalar(data):
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return QtGui.QColor(*interp)
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else:
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return [QtGui.QColor(*x) for x in interp]
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else:
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return interp
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def mapToQColor(self, data):
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"""Convenience function; see :func:`map() <pyqtgraph.ColorMap.map>`."""
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return self.map(data, mode=self.QCOLOR)
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def mapToByte(self, data):
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"""Convenience function; see :func:`map() <pyqtgraph.ColorMap.map>`."""
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return self.map(data, mode=self.BYTE)
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def mapToFloat(self, data):
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"""Convenience function; see :func:`map() <pyqtgraph.ColorMap.map>`."""
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return self.map(data, mode=self.FLOAT)
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def getGradient(self, p1=None, p2=None):
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"""Return a QLinearGradient object spanning from QPoints p1 to p2."""
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if p1 == None:
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p1 = QtCore.QPointF(0,0)
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if p2 == None:
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p2 = QtCore.QPointF(self.pos.max()-self.pos.min(),0)
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g = QtGui.QLinearGradient(p1, p2)
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pos, color = self.getStops(mode=self.BYTE)
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color = [QtGui.QColor(*x) for x in color]
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g.setStops(zip(pos, color))
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#if self.colorMode == 'rgb':
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#ticks = self.listTicks()
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#g.setStops([(x, QtGui.QColor(t.color)) for t,x in ticks])
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#elif self.colorMode == 'hsv': ## HSV mode is approximated for display by interpolating 10 points between each stop
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#ticks = self.listTicks()
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#stops = []
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#stops.append((ticks[0][1], ticks[0][0].color))
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#for i in range(1,len(ticks)):
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#x1 = ticks[i-1][1]
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#x2 = ticks[i][1]
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#dx = (x2-x1) / 10.
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#for j in range(1,10):
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#x = x1 + dx*j
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#stops.append((x, self.getColor(x)))
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#stops.append((x2, self.getColor(x2)))
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#g.setStops(stops)
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return g
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def getColors(self, mode=None):
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"""Return list of all color stops converted to the specified mode.
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If mode is None, then no conversion is done."""
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if isinstance(mode, basestring):
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mode = self.enumMap[mode.lower()]
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color = self.color
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if mode in [self.BYTE, self.QCOLOR] and color.dtype.kind == 'f':
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color = (color * 255).astype(np.ubyte)
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elif mode == self.FLOAT and color.dtype.kind != 'f':
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color = color.astype(float) / 255.
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if mode == self.QCOLOR:
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color = [QtGui.QColor(*x) for x in color]
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return color
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def getStops(self, mode):
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## Get fully-expanded set of RGBA stops in either float or byte mode.
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if mode not in self.stopsCache:
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color = self.color
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if mode == self.BYTE and color.dtype.kind == 'f':
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color = (color * 255).astype(np.ubyte)
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elif mode == self.FLOAT and color.dtype.kind != 'f':
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color = color.astype(float) / 255.
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## to support HSV mode, we need to do a little more work..
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#stops = []
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#for i in range(len(self.pos)):
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#pos = self.pos[i]
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#color = color[i]
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#imode = self.mode[i]
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#if imode == self.RGB:
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#stops.append((x,color))
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#else:
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#ns =
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self.stopsCache[mode] = (self.pos, color)
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return self.stopsCache[mode]
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def getLookupTable(self, start=0.0, stop=1.0, nPts=512, alpha=None, mode='byte'):
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"""
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Return an RGB(A) lookup table (ndarray).
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=============== =============================================================================
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**Arguments:**
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start The starting value in the lookup table (default=0.0)
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stop The final value in the lookup table (default=1.0)
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nPts The number of points in the returned lookup table.
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alpha True, False, or None - Specifies whether or not alpha values are included
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in the table. If alpha is None, it will be automatically determined.
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mode Determines return type: 'byte' (0-255), 'float' (0.0-1.0), or 'qcolor'.
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See :func:`map() <pyqtgraph.ColorMap.map>`.
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=============== =============================================================================
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"""
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if isinstance(mode, basestring):
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mode = self.enumMap[mode.lower()]
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if alpha is None:
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alpha = self.usesAlpha()
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x = np.linspace(start, stop, nPts)
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table = self.map(x, mode)
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if not alpha:
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return table[:,:3]
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else:
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return table
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def usesAlpha(self):
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"""Return True if any stops have an alpha < 255"""
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max = 1.0 if self.color.dtype.kind == 'f' else 255
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return np.any(self.color[:,3] != max)
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def isMapTrivial(self):
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"""
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Return True if the gradient has exactly two stops in it: black at 0.0 and white at 1.0.
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"""
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if len(self.pos) != 2:
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return False
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if self.pos[0] != 0.0 or self.pos[1] != 1.0:
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return False
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if self.color.dtype.kind == 'f':
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return np.all(self.color == np.array([[0.,0.,0.,1.], [1.,1.,1.,1.]]))
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else:
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return np.all(self.color == np.array([[0,0,0,255], [255,255,255,255]]))
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def __repr__(self):
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pos = repr(self.pos).replace('\n', '')
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color = repr(self.color).replace('\n', '')
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return "ColorMap(%s, %s)" % (pos, color)
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