matplotlib.github.com/2.2.3/tutorials/colors/colors.html at main · matplotlib/matplotlib.github.com

History

286 lines (251 loc) · 25.4 KB

Raw

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

225

226

227

228

229

230

231

232

233

234

235

236

237

238

239

240

241

242

243

244

245

246

247

248

249

250

251

252

253

254

255

256

257

258

259

260

261

262

263

264

265

266

267

268

269

270

271

272

273

274

275

276

277

278

279

280

281

282

283

284

285

286

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"

"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<head>

<title>Specifying Colors — Matplotlib 2.2.3 documentation</title>

type="text/css" />

type="text/css" />

var DOCUMENTATION_OPTIONS = {

URL_ROOT: '../../',

VERSION: '2.2.3',

COLLAPSE_INDEX: false,

FILE_SUFFIX: '.html',

HAS_SOURCE: true,

SOURCELINK_SUFFIX: '.txt'

};

</script>

title="Search within Matplotlib 2.2.3 documentation"

href="../../_static/opensearch.xml"/>

</head>

<body>

<div id="unreleased-message"> You are reading an old version of the documentation (v2.2.3). For the latest version see <a href="https://matplotlib.org/stable/tutorials/colors/colors.html">https://matplotlib.org/stable/tutorials/colors/colors.html</a></div>

<div style="float: left; position: absolute; width: 496px; bottom: 0; padding-bottom: 24px">Version 2.2.3</div>

<div id="forkongithub"><a href="https://github.com/matplotlib/matplotlib">Fork me on GitHub</a></div>

</div>

<h3>Navigation</h3>

<ul>

<a href="../../genindex.html" title="General Index"

accesskey="I">index</a></li>

<a href="../../py-modindex.html" title="Python Module Index"

>modules</a> |</li>

<a href="colorbar_only.html" title="Customized Colorbars Tutorial"

accesskey="N">next</a> |</li>

<a href="../advanced/transforms_tutorial.html" title="Transformations Tutorial"

accesskey="P">previous</a> |</li>

<li><a href="../../gallery/index.html">examples</a>| </li>

<li><a href="../index.html">tutorials</a>| </li>

<li><a href="../../api/pyplot_summary.html">pyplot</a>| </li>

<li><a href="../../users/index.html" >User's Guide</a> »</li>

<li><a href="../index.html" accesskey="U">Tutorials</a> »</li>

</ul>

</div>

<h3>Quick search</h3>

</form>

</div>

<h3><a href="../../contents.html">Table Of Contents</a></h3>

<ul>

<li><a class="reference internal" href="#">Specifying Colors</a><ul>

<li><a class="reference internal" href="#cn-color-selection">"CN" color selection</a></li>

</ul>

</li>

</ul>

<h3>Related Topics</h3>

<ul>

<li><a href="../../contents.html">Documentation overview</a><ul>

<li><a href="../../users/index.html">User's Guide</a><ul>

<li><a href="../index.html">Tutorials</a><ul>

<li>Previous: <a href="../advanced/transforms_tutorial.html" title="previous chapter">Transformations Tutorial</a></li>

<li>Next: <a href="colorbar_only.html" title="next chapter">Customized Colorbars Tutorial</a></li>

</ul></li>

</ul>

</div>

<div id="sidebar-pagesource" role="note" aria-label="source link"

style="margin-top: 1.5em; padding-top: 0.1em; border-top: 1px solid #86989b">

<a href="../../_sources/tutorials/colors/colors.rst.txt"

style="color: #c0c0c0" rel="nofollow">Show Page Source</a>

</div>

Note

Click <a class="reference internal" href="#sphx-glr-download-tutorials-colors-colors-py">here</a> to download the full example code

</div>

<h1>Specifying Colors<a class="headerlink" href="#specifying-colors" title="Permalink to this headline">¶</a></h1>

Matplotlib recognizes the following formats to specify a color:

<li>an RGB or RGBA tuple of float values in <code class="docutils literal notranslate">[0, 1]</code> (e.g., <code class="docutils literal notranslate">(0.1, 0.2, 0.5)</code>

or <code class="docutils literal notranslate">(0.1, 0.2, 0.5, 0.3)</code>). RGBA is short for Red, Green, Blue, Alpha;</li>

<li>a hex RGB or RGBA string (e.g., <code class="docutils literal notranslate">'#0F0F0F'</code> or <code class="docutils literal notranslate">'#0F0F0F0F'</code>);</li>

<li>a string representation of a float value in <code class="docutils literal notranslate">[0, 1]</code> inclusive for gray

level (e.g., <code class="docutils literal notranslate">'0.5'</code>);</li>

<li>a X11/CSS4 color name;</li>

<li>a name from the <a class="reference external" href="https://xkcd.com/color/rgb/">xkcd color survey</a>;

prefixed with <code class="docutils literal notranslate">'xkcd:'</code> (e.g., <code class="docutils literal notranslate">'xkcd:sky blue'</code>);</li>

<li>one of <code class="docutils literal notranslate">{'tab:blue', 'tab:orange', 'tab:green',

'tab:red', 'tab:purple', 'tab:brown', 'tab:pink',

'tab:gray', 'tab:olive', 'tab:cyan'}</code> which are the Tableau Colors from the

'T10' categorical palette (which is the default color cycle);</li>

<li>a "CN" color spec, i.e. <code class="xref py py-obj docutils literal notranslate">'C'</code> followed by a single digit, which is an index

into the default property cycle (<code class="docutils literal notranslate">matplotlib.rcParams['axes.prop_cycle']</code>);

the indexing occurs at artist creation time and defaults to black if the

cycle does not include color.</li>

</ul>

"Red", "Green" and "Blue", are the intensities of those colors, the combination

of which span the colorspace.

How "Alpha" behaves depends on the <code class="docutils literal notranslate">zorder</code> of the Artist. Higher

<code class="docutils literal notranslate">zorder</code> Artists are drawn on top of lower Artists, and "Alpha" determines

whether the lower artist is covered by the higher.

If the old RGB of a pixel is <code class="docutils literal notranslate">RGBold</code> and the RGB of the

pixel of the Artist being added is <code class="docutils literal notranslate">RGBnew</code> with Alpha <code class="docutils literal notranslate">alpha</code>,

then the RGB of the pixel is updated to:

<code class="docutils literal notranslate">RGB = RGBOld * (1 - Alpha) + RGBnew * Alpha</code>. Alpha

of 1 means the old color is completely covered by the new Artist, Alpha of 0

means that pixel of the Artist is transparent.

All string specifications of color, other than "CN", are case-insensitive.

<h2>"CN" color selection<a class="headerlink" href="#cn-color-selection" title="Permalink to this headline">¶</a></h2>

"CN" colors are converted to RGBA as soon as the artist is created. For

example,

<div class="highlight-python notranslate"><div class="highlight"><pre>import numpy as np

import matplotlib.pyplot as plt

import matplotlib as mpl

th = <a href="https://docs.scipy.org/doc/numpy/reference/generated/numpy.linspace.html#numpy.linspace" title="View documentation for numpy.linspace">np.linspace</a>(0, 2*<a href="https://docs.scipy.org/doc/numpy/reference/constants.html#numpy.pi" title="View documentation for numpy.pi">np.pi</a>, 128)

def demo(sty):

<a href="../../api/style_api.html#matplotlib.style.use" title="View documentation for matplotlib.style.use">mpl.style.use</a>(sty)

fig, ax = <a href="../../api/_as_gen/matplotlib.pyplot.subplots.html#matplotlib.pyplot.subplots" title="View documentation for matplotlib.pyplot.subplots">plt.subplots</a>(figsize=(3, 3))

ax.set_title('style: {!r}'.format(sty), color='C0')

ax.plot(th, <a href="https://docs.scipy.org/doc/numpy/reference/generated/numpy.cos.html#numpy.cos" title="View documentation for numpy.cos">np.cos</a>(th), 'C1', label='C1')

ax.plot(th, <a href="https://docs.scipy.org/doc/numpy/reference/generated/numpy.sin.html#numpy.sin" title="View documentation for numpy.sin">np.sin</a>(th), 'C2', label='C2')

ax.legend()

demo('default')

demo('seaborn')

</pre></div>

</div>

</li>

</li>

</ul>

will use the first color for the title and then plot using the second

and third colors of each style's <code class="docutils literal notranslate">mpl.rcParams['axes.prop_cycle']</code>.

</div>

The xkcd colors are derived from a user survey conducted by the

webcomic xkcd. <a class="reference external" href="https://blog.xkcd.com/2010/05/03/color-survey-results/">Details of the survey are available on the xkcd blog</a>.

Out of 148 colors in the CSS color list, there are 95 name collisions

between the X11/CSS4 names and the xkcd names, all but 3 of which have

different hex values. For example <code class="docutils literal notranslate">'blue'</code> maps to <code class="docutils literal notranslate">'#0000FF'</code>

where as <code class="docutils literal notranslate">'xkcd:blue'</code> maps to <code class="docutils literal notranslate">'#0343DF'</code>. Due to these name

collisions all of the xkcd colors have <code class="docutils literal notranslate">'xkcd:'</code> prefixed. As noted in

the blog post, while it might be interesting to re-define the X11/CSS4 names

based on such a survey, we do not do so unilaterally.

The name collisions are shown in the table below; the color names

where the hex values agree are shown in bold.

<div class="highlight-python notranslate"><div class="highlight"><pre>import matplotlib._color_data as mcd

import matplotlib.patches as mpatch

overlap = {name for name in mcd.CSS4_COLORS

if "xkcd:" + name in mcd.XKCD_COLORS}

fig = <a href="../../api/_as_gen/matplotlib.pyplot.figure.html#matplotlib.pyplot.figure" title="View documentation for matplotlib.pyplot.figure">plt.figure</a>(figsize=[4.8, 16])

ax = fig.add_axes([0, 0, 1, 1])

for j, n in enumerate(sorted(overlap, reverse=True)):

weight = None

cn = mcd.CSS4_COLORS[n]

xkcd = mcd.XKCD_COLORS["xkcd:" + n].upper()

if cn == xkcd:

weight = 'bold'

r1 = <a href="../../api/_as_gen/matplotlib.patches.Rectangle.html#matplotlib.patches.Rectangle" title="View documentation for matplotlib.patches.Rectangle">mpatch.Rectangle</a>((0, j), 1, 1, color=cn)

r2 = <a href="../../api/_as_gen/matplotlib.patches.Rectangle.html#matplotlib.patches.Rectangle" title="View documentation for matplotlib.patches.Rectangle">mpatch.Rectangle</a>((1, j), 1, 1, color=xkcd)

txt = ax.text(2, j+.5, ' ' + n, va='center', fontsize=10,

weight=weight)

ax.add_patch(r1)

ax.add_patch(r2)

ax.axhline(j, color='k')

ax.text(.5, j + 1.5, 'X11', ha='center', va='center')

ax.text(1.5, j + 1.5, 'xkcd', ha='center', va='center')

ax.set_xlim(0, 3)

ax.set_ylim(0, j + 2)

ax.axis('off')

</pre></div>

</div>

<a class="reference download internal" href="../../_downloads/colors.py" download=""><code class="xref download docutils literal notranslate">Download Python source code: colors.py</code></a></div>

<a class="reference download internal" href="../../_downloads/colors.ipynb" download=""><code class="xref download docutils literal notranslate">Download Jupyter notebook: colors.ipynb</code></a></div>

</div>

Keywords: matplotlib code example, codex, python plot, pyplot

<a class="reference external" href="https://sphinx-gallery.readthedocs.io">Gallery generated by Sphinx-Gallery</a>

</div>

</div>

Last updated on Aug 11, 2018.

Created using

<ahref="http://sphinx-doc.org/">Sphinx</a> 1.7.6.

Doc version v2.2.3-1-gd47e15e7a.

</div>

</body>

</footer>

</html>

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

FilesExpand file tree

colors.html

Latest commit

History

colors.html

File metadata and controls