1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
|
# coding: utf-8
# /*##########################################################################
#
# Copyright (c) 2014-2017 European Synchrotron Radiation Facility
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
#
# ###########################################################################*/
"""This module implements labels layout on graph axes."""
from __future__ import absolute_import, division, unicode_literals
__authors__ = ["T. Vincent"]
__license__ = "MIT"
__date__ = "18/10/2016"
import math
# utils #######################################################################
def numberOfDigits(tickSpacing):
"""Returns the number of digits to display for text label.
:param float tickSpacing: Step between ticks in data space.
:return: Number of digits to show for labels.
:rtype: int
"""
nfrac = int(-math.floor(math.log10(tickSpacing)))
if nfrac < 0:
nfrac = 0
return nfrac
# Nice Numbers ################################################################
def _niceNum(value, isRound=False):
expvalue = math.floor(math.log10(value))
frac = value/pow(10., expvalue)
if isRound:
if frac < 1.5:
nicefrac = 1.
elif frac < 3.:
nicefrac = 2.
elif frac < 7.:
nicefrac = 5.
else:
nicefrac = 10.
else:
if frac <= 1.:
nicefrac = 1.
elif frac <= 2.:
nicefrac = 2.
elif frac <= 5.:
nicefrac = 5.
else:
nicefrac = 10.
return nicefrac * pow(10., expvalue)
def niceNumbers(vMin, vMax, nTicks=5):
"""Returns tick positions.
This function implements graph labels layout using nice numbers
by Paul Heckbert from "Graphics Gems", Academic Press, 1990.
See `C code <http://tog.acm.org/resources/GraphicsGems/gems/Label.c>`_.
:param float vMin: The min value on the axis
:param float vMax: The max value on the axis
:param int nTicks: The number of ticks to position
:returns: min, max, increment value of tick positions and
number of fractional digit to show
:rtype: tuple
"""
vrange = _niceNum(vMax - vMin, False)
spacing = _niceNum(vrange / nTicks, True)
graphmin = math.floor(vMin / spacing) * spacing
graphmax = math.ceil(vMax / spacing) * spacing
nfrac = numberOfDigits(spacing)
return graphmin, graphmax, spacing, nfrac
def _frange(start, stop, step):
"""range for float (including stop)."""
assert step >= 0.
while start <= stop:
yield start
start += step
def ticks(vMin, vMax, nbTicks=5):
"""Returns tick positions and labels using nice numbers algorithm.
This enforces ticks to be within [vMin, vMax] range.
It returns at least 2 ticks.
:param float vMin: The min value on the axis
:param float vMax: The max value on the axis
:param int nbTicks: The number of ticks to position
:returns: tick positions and corresponding text labels
:rtype: 2-tuple: list of float, list of string
"""
start, end, step, nfrac = niceNumbers(vMin, vMax, nbTicks)
positions = [t for t in _frange(start, end, step) if vMin <= t <= vMax]
# Makes sure there is at least 2 ticks
if len(positions) < 2:
positions = [vMin, vMax]
nfrac = numberOfDigits(vMax - vMin)
# Generate labels
format_ = '%g' if nfrac == 0 else '%.{}f'.format(nfrac)
labels = [format_ % tick for tick in positions]
return positions, labels
def niceNumbersAdaptative(vMin, vMax, axisLength, tickDensity):
"""Returns tick positions using :func:`niceNumbers` and a
density of ticks.
axisLength and tickDensity are based on the same unit (e.g., pixel).
:param float vMin: The min value on the axis
:param float vMax: The max value on the axis
:param float axisLength: The length of the axis.
:param float tickDensity: The density of ticks along the axis.
:returns: min, max, increment value of tick positions and
number of fractional digit to show
:rtype: tuple
"""
# At least 2 ticks
nticks = max(2, int(round(tickDensity * axisLength)))
tickmin, tickmax, step, nfrac = niceNumbers(vMin, vMax, nticks)
return tickmin, tickmax, step, nfrac
# Nice Numbers for log scale ##################################################
def niceNumbersForLog10(minLog, maxLog, nTicks=5):
"""Return tick positions for logarithmic scale
:param float minLog: log10 of the min value on the axis
:param float maxLog: log10 of the max value on the axis
:param int nTicks: The number of ticks to position
:returns: log10 of min, max, increment value of tick positions and
number of fractional digit to show
:rtype: tuple of int
"""
graphminlog = math.floor(minLog)
graphmaxlog = math.ceil(maxLog)
rangelog = graphmaxlog - graphminlog
if rangelog <= nTicks:
spacing = 1.
else:
spacing = math.floor(rangelog / nTicks)
graphminlog = math.floor(graphminlog / spacing) * spacing
graphmaxlog = math.ceil(graphmaxlog / spacing) * spacing
nfrac = numberOfDigits(spacing)
return int(graphminlog), int(graphmaxlog), int(spacing), nfrac
def niceNumbersAdaptativeForLog10(vMin, vMax, axisLength, tickDensity):
"""Returns tick positions using :func:`niceNumbers` and a
density of ticks.
axisLength and tickDensity are based on the same unit (e.g., pixel).
:param float vMin: The min value on the axis
:param float vMax: The max value on the axis
:param float axisLength: The length of the axis.
:param float tickDensity: The density of ticks along the axis.
:returns: log10 of min, max, increment value of tick positions and
number of fractional digit to show
:rtype: tuple
"""
# At least 2 ticks
nticks = max(2, int(round(tickDensity * axisLength)))
tickmin, tickmax, step, nfrac = niceNumbersForLog10(vMin, vMax, nticks)
return tickmin, tickmax, step, nfrac
def computeLogSubTicks(ticks, lowBound, highBound):
"""Return the sub ticks for the log scale for all given ticks if subtick
is in [lowBound, highBound]
:param ticks: log10 of the ticks
:param lowBound: the lower boundary of ticks
:param highBound: the higher boundary of ticks
:return: all the sub ticks contained in ticks (log10)
"""
if len(ticks) < 1:
return []
res = []
for logPos in ticks:
dataOrigPos = logPos
for index in range(2, 10):
dataPos = dataOrigPos * index
if lowBound <= dataPos <= highBound:
res.append(dataPos)
return res
|
