matplotlib.github.com/3.4.2/_modules/matplotlib/units.html at main · matplotlib/matplotlib.github.com

History

347 lines (290 loc) · 27.8 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

287

288

289

290

291

292

293

294

295

296

297

298

299

300

301

302

303

304

305

306

307

308

309

310

311

312

313

314

315

316

317

318

319

320

321

322

323

324

325

326

327

328

329

330

331

332

333

334

335

336

337

338

339

340

341

342

343

344

345

346

347

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

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

<head>

<title>matplotlib.units — Matplotlib 3.4.2 documentation</title>

title="Search within Matplotlib 3.4.2 documentation"

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

</head><body>

<div id="unreleased-message"> You are reading an old version of the documentation (v3.4.2). For the latest version see <a href="/stable/">https://matplotlib.org/stable/</a> </div>

<!--

</div>

-->

<div style="float: left; position: absolute; width: 496px; bottom: 0; padding-bottom: 24px">Version 3.4.2</div>

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

</div>

<ul>

<li><a href="../../users/installing.html">Installation</a></li>

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

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

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

<li><a href="../../devel/index.html">Contributing</a></li>

</form>

</li>

</ul>

</nav>

<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>

<li><a href="../../contents.html">contents</a> »</li>

<li class="nav-item nav-item-1"><a href="../index.html" >Module code</a> »</li>

<li class="nav-item nav-item-2"><a href="../matplotlib.html" accesskey="U">matplotlib</a> »</li>

<li class="nav-item nav-item-this"><a href="">matplotlib.units</a></li>

</ul>

</div>

</div>

<h1>Source code for matplotlib.units</h1><div class="highlight"><pre>

"""

The classes here provide support for using custom classes with

Matplotlib, e.g., those that do not expose the array interface but know

how to convert themselves to arrays. It also supports classes with

units and units conversion. Use cases include converters for custom

objects, e.g., a list of datetime objects, as well as for objects that

are unit aware. We don't assume any particular units implementation;

rather a units implementation must provide the register with the Registry

converter dictionary and a `ConversionInterface`. For example,

here is a complete implementation which supports plotting with native

datetime objects::

import matplotlib.units as units

import matplotlib.dates as dates

import matplotlib.ticker as ticker

import datetime

class DateConverter(units.ConversionInterface):

@staticmethod

def convert(value, unit, axis):

'Convert a datetime value to a scalar or array'

return dates.date2num(value)

@staticmethod

def axisinfo(unit, axis):

'Return major and minor tick locators and formatters'

if unit!='date': return None

majloc = dates.AutoDateLocator()

majfmt = dates.AutoDateFormatter(majloc)

return AxisInfo(majloc=majloc,

majfmt=majfmt,

label='date')

@staticmethod

def default_units(x, axis):

'Return the default unit for x or None'

return 'date'

# Finally we register our object type with the Matplotlib units registry.

units.registry[datetime.date] = DateConverter()

"""

from decimal import Decimal

from numbers import Number

import numpy as np

from numpy import ma

from matplotlib import cbook

<div class="viewcode-block" id="ConversionError"><a class="viewcode-back" href="../../api/units_api.html#matplotlib.units.ConversionError">[docs]</a>class ConversionError(TypeError):

pass</div>

def _is_natively_supported(x):

"""

Return whether *x* is of a type that Matplotlib natively supports or an

array of objects of such types.

"""

# Matplotlib natively supports all number types except Decimal.

if np.iterable(x):

# Assume lists are homogeneous as other functions in unit system.

for thisx in x:

if thisx is ma.masked:

continue

return isinstance(thisx, Number) and not isinstance(thisx, Decimal)

else:

return isinstance(x, Number) and not isinstance(x, Decimal)

<div class="viewcode-block" id="AxisInfo"><a class="viewcode-back" href="../../api/units_api.html#matplotlib.units.AxisInfo">[docs]</a>class AxisInfo:

"""

Information to support default axis labeling, tick labeling, and limits.

An instance of this class must be returned by

`ConversionInterface.axisinfo`.

"""

def __init__(self, majloc=None, minloc=None,

majfmt=None, minfmt=None, label=None,

default_limits=None):

"""

Parameters

----------

majloc, minloc : Locator, optional

Tick locators for the major and minor ticks.

majfmt, minfmt : Formatter, optional

Tick formatters for the major and minor ticks.

label : str, optional

The default axis label.

default_limits : optional

The default min and max limits of the axis if no data has

been plotted.

Notes

-----

If any of the above are ``None``, the axis will simply use the

default value.

"""

self.majloc = majloc

self.minloc = minloc

self.majfmt = majfmt

self.minfmt = minfmt

self.label = label

self.default_limits = default_limits</div>

<div class="viewcode-block" id="ConversionInterface"><a class="viewcode-back" href="../../api/units_api.html#matplotlib.units.ConversionInterface">[docs]</a>class ConversionInterface:

"""

The minimal interface for a converter to take custom data types (or

sequences) and convert them to values Matplotlib can use.

"""

<div class="viewcode-block" id="ConversionInterface.axisinfo"><a class="viewcode-back" href="../../api/units_api.html#matplotlib.units.ConversionInterface.axisinfo">[docs]</a> @staticmethod

def axisinfo(unit, axis):

"""Return an `.AxisInfo` for the axis with the specified units."""

return None</div>

<div class="viewcode-block" id="ConversionInterface.default_units"><a class="viewcode-back" href="../../api/units_api.html#matplotlib.units.ConversionInterface.default_units">[docs]</a> @staticmethod

def default_units(x, axis):

"""Return the default unit for *x* or ``None`` for the given axis."""

return None</div>

<div class="viewcode-block" id="ConversionInterface.convert"><a class="viewcode-back" href="../../api/units_api.html#matplotlib.units.ConversionInterface.convert">[docs]</a> @staticmethod

def convert(obj, unit, axis):

"""

Convert *obj* using *unit* for the specified *axis*.

If *obj* is a sequence, return the converted sequence. The output must

be a sequence of scalars that can be used by the numpy array layer.

"""

return obj</div>

<div class="viewcode-block" id="ConversionInterface.is_numlike"><a class="viewcode-back" href="../../api/units_api.html#matplotlib.units.ConversionInterface.is_numlike">[docs]</a> @staticmethod

def is_numlike(x):

"""

The Matplotlib datalim, autoscaling, locators etc work with scalars

which are the units converted to floats given the current unit. The

converter may be passed these floats, or arrays of them, even when

units are set.

"""

if np.iterable(x):

for thisx in x:

if thisx is ma.masked:

continue

return isinstance(thisx, Number)

else:

<div class="viewcode-block" id="DecimalConverter"><a class="viewcode-back" href="../../api/units_api.html#matplotlib.units.DecimalConverter">[docs]</a>class DecimalConverter(ConversionInterface):

"""Converter for decimal.Decimal data to float."""

<div class="viewcode-block" id="DecimalConverter.convert"><a class="viewcode-back" href="../../api/units_api.html#matplotlib.units.DecimalConverter.convert">[docs]</a> @staticmethod

def convert(value, unit, axis):

"""

Convert Decimals to floats.

The *unit* and *axis* arguments are not used.

Parameters

----------

value : decimal.Decimal or iterable

Decimal or list of Decimal need to be converted

"""

# If value is a Decimal

if isinstance(value, Decimal):

return float(value)

else:

# assume x is a list of Decimal

converter = np.asarray

if isinstance(value, ma.MaskedArray):

converter = ma.asarray

return converter(value, dtype=float)</div>

<div class="viewcode-block" id="DecimalConverter.axisinfo"><a class="viewcode-back" href="../../api/units_api.html#matplotlib.units.DecimalConverter.axisinfo">[docs]</a> @staticmethod

def axisinfo(unit, axis):

# Since Decimal is a kind of Number, don't need specific axisinfo.

return AxisInfo()</div>

<div class="viewcode-block" id="DecimalConverter.default_units"><a class="viewcode-back" href="../../api/units_api.html#matplotlib.units.DecimalConverter.default_units">[docs]</a> @staticmethod

def default_units(x, axis):

# Return None since Decimal is a kind of Number.

return None</div></div>

<div class="viewcode-block" id="Registry"><a class="viewcode-back" href="../../api/units_api.html#matplotlib.units.Registry">[docs]</a>class Registry(dict):

"""Register types with conversion interface."""

<div class="viewcode-block" id="Registry.get_converter"><a class="viewcode-back" href="../../api/units_api.html#matplotlib.units.Registry.get_converter">[docs]</a> def get_converter(self, x):

"""Get the converter interface instance for *x*, or None."""

if hasattr(x, "values"):

x = x.values # Unpack pandas Series and DataFrames.

if isinstance(x, np.ndarray):

# In case x in a masked array, access the underlying data (only its

# type matters). If x is a regular ndarray, getdata() just returns

# the array itself.

x = np.ma.getdata(x).ravel()

# If there are no elements in x, infer the units from its dtype

if not x.size:

return self.get_converter(np.array([0], dtype=x.dtype))

for cls in type(x).__mro__: # Look up in the cache.

try:

return self[cls]

except KeyError:

pass

try: # If cache lookup fails, look up based on first element...

first = cbook.safe_first_element(x)

except (TypeError, StopIteration):

pass

else:

# ... and avoid infinite recursion for pathological iterables for

# which indexing returns instances of the same iterable class.

if type(first) is not type(x):

return self.get_converter(first)

return None</div></div>

registry = Registry()

registry[Decimal] = DecimalConverter()

</pre></div>

</div>

</div>

Last updated on May 08, 2021.

Created using

<a href="http://sphinx-doc.org/">Sphinx</a> 3.2.1.

Doc version v3.4.2-2-gf801f04d09-dirty.

</div>

</footer>

</body>

</html>

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

FilesExpand file tree

units.html

Latest commit

History

units.html

File metadata and controls