pyqtgraph/functions.py
2010-05-01 12:19:27 -04:00

91 lines
2.5 KiB
Python

# -*- coding: utf-8 -*-
"""
functions.py - Miscellaneous functions with no other home
Copyright 2010 Luke Campagnola
Distributed under MIT/X11 license. See license.txt for more infomation.
"""
from PyQt4 import QtGui
from numpy import clip, floor, log
## Copied from acq4/lib/util/functions
SI_PREFIXES = u'yzafpnµm kMGTPEZY'
def siScale(x, minVal=1e-25):
"""Return the recommended scale factor and SI prefix string for x."""
if abs(x) < minVal:
m = 0
x = 0
else:
m = int(clip(floor(log(abs(x))/log(1000)), -9.0, 9.0))
if m == 0:
pref = ''
elif m < -8 or m > 8:
pref = 'e%d' % (m*3)
else:
pref = SI_PREFIXES[m+8]
p = .001**m
return (p, pref)
def mkPen(color=None, width=1, style=None, cosmetic=True, hsv=None, ):
if color is None:
color = [255, 255, 255]
if hsv is not None:
color = hsvColor(*hsv)
else:
color = mkColor(color)
pen = QtGui.QPen(QtGui.QBrush(color), width)
pen.setCosmetic(cosmetic)
if style is not None:
pen.setStyle(style)
return pen
def hsvColor(h, s=1.0, v=1.0, a=1.0):
c = QtGui.QColor()
c.setHsvF(h, s, v, a)
return c
def mkColor(*args):
"""make a QColor from a variety of argument types"""
err = 'Not sure how to make a color from "%s"' % str(args)
if len(args) == 1:
if isinstance(args[0], QtGui.QColor):
return QtGui.QColor(args[0])
elif hasattr(args[0], '__len__'):
if len(args[0]) == 3:
(r, g, b) = args[0]
a = 255
elif len(args[0]) == 4:
(r, g, b, a) = args[0]
else:
raise Exception(err)
else:
raise Exception(err)
elif len(args) == 3:
(r, g, b) = args
a = 255
elif len(args) == 4:
(r, g, b, a) = args
else:
raise Exception(err)
return QtGui.QColor(r, g, b, a)
def colorStr(c):
"""Generate a hex string code from a QColor"""
return ('%02x'*4) % (c.red(), c.blue(), c.green(), c.alpha())
def intColor(ind, colors=9, values=3, maxValue=255, minValue=150, sat=255):
"""Creates a QColor from a single index. Useful for stepping through a predefined list of colors."""
colors = int(colors)
values = int(values)
ind = int(ind) % (colors * values)
indh = ind % colors
indv = ind / colors
v = minValue + indv * ((maxValue-minValue) / (values-1))
h = (indh * 360) / colors
c = QtGui.QColor()
c.setHsv(h, sat, v)
return c