add transformation function

docs/build/html/function.html

@@ -37,7 +37,7 @@
 <p>Mathematical equations.</p>
 <dl class="field-list simple">
 <dt class="field-odd">Date</dt>
-<dd class="field-odd"><p>2019-11-02</p>
+<dd class="field-odd"><p>2019-11-04</p>
 </dd>
 </dl>
 <span class="target" id="module-function"></span><dl class="function">
@@ -232,6 +232,35 @@ linear speed.</p>
 </div>
 </dd></dl>
 
+<dl class="function">
+<dt id="function.transformation">
+<code class="sig-name descname">transformation</code><span class="sig-paren">(</span><em class="sig-param">f</em>, <em class="sig-param">scale_vertical=1</em>, <em class="sig-param">scale_horizontal=1</em>, <em class="sig-param">shift_horizontal=0</em>, <em class="sig-param">shift_vertical=0</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/function.html#transformation"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#function.transformation" title="Permalink to this definition">¶</a></dt>
+<dd><p>Transform functions.</p>
+<dl class="field-list simple">
+<dt class="field-odd">Parameters</dt>
+<dd class="field-odd"><ul class="simple">
+<li><p><strong>f</strong> (<em>function</em><em> or </em><em>list</em>) – function or list of functions</p></li>
+<li><p><strong>scale_vertical</strong> – “a” scale factor in vertical direction (default
+= 1)</p></li>
+<li><p><strong>scale_horizontal</strong> – “b” scale factor in horizontal direction
+(default = 1)</p></li>
+<li><p><strong>shift_horizontal</strong> – “c” shift factor in horizontal direction
+(default = 0)</p></li>
+<li><p><strong>shift_vertical</strong> – “d” shift factor in vertical direction (default
+= 0)</p></li>
+</ul>
+</dd>
+<dt class="field-even">Returns</dt>
+<dd class="field-even"><p>transformed function or list of transformed functions</p>
+</dd>
+<dt class="field-odd">Return type</dt>
+<dd class="field-odd"><p>function or list</p>
+</dd>
+</dl>
+<div class="math notranslate nohighlight">
+\[y = a \, f(b\,(x-c)) + d\]</div>
+</dd></dl>
+
 </div>