From 3ad65aa3c537e1e39f2abf4917ab13a19f419fb9 Mon Sep 17 00:00:00 2001 From: Andy Date: Thu, 30 Mar 2017 02:55:40 -0700 Subject: [PATCH] added example to README plus minor changed example regarding computing many points quickly with numpy arrays --- README.ipynb | 45 ++++++++++++++++++++-------------- README.rst | 64 +++++++++++++++++++++++++----------------------- disvg_output.svg | 2 +- 3 files changed, 61 insertions(+), 50 deletions(-) diff --git a/README.ipynb b/README.ipynb index d3d563c..eff9e5b 100644 --- a/README.ipynb +++ b/README.ipynb @@ -86,7 +86,7 @@ }, { "cell_type": "code", - "execution_count": 5, + "execution_count": 1, "metadata": { "collapsed": true }, @@ -97,7 +97,7 @@ }, { "cell_type": "code", - "execution_count": 6, + "execution_count": 2, "metadata": { "collapsed": false }, @@ -147,7 +147,7 @@ }, { "cell_type": "code", - "execution_count": 7, + "execution_count": 3, "metadata": { "collapsed": false }, @@ -224,7 +224,7 @@ }, { "cell_type": "code", - "execution_count": 8, + "execution_count": 4, "metadata": { "collapsed": false }, @@ -270,7 +270,7 @@ }, { "cell_type": "code", - "execution_count": 9, + "execution_count": 5, "metadata": { "collapsed": false }, @@ -305,7 +305,7 @@ }, { "cell_type": "code", - "execution_count": 10, + "execution_count": 6, "metadata": { "collapsed": false }, @@ -346,8 +346,8 @@ "cell_type": "markdown", "metadata": {}, "source": [ - "### Tangent vectors and Bezier curves as numpy polynomial objects\n", - "Another great way to work with the parameterizations for Line, QuadraticBezier, and CubicBezier objects is to convert them to ``numpy.poly1d`` objects. This is done easily using the ``Line.poly()``, ``QuadraticBezier.poly()`` and ``CubicBezier.poly()`` methods. \n", + "### Bezier curves as NumPy polynomial objects\n", + "Another great way to work with the parameterizations for `Line`, `QuadraticBezier`, and `CubicBezier` objects is to convert them to ``numpy.poly1d`` objects. This is done easily using the ``Line.poly()``, ``QuadraticBezier.poly()`` and ``CubicBezier.poly()`` methods. \n", "There's also a ``polynomial2bezier()`` function in the pathtools.py submodule to convert polynomials back to Bezier curves. \n", "\n", "**Note:** cubic Bezier curves are parameterized as $$\\mathcal{B}(t) = P_0(1-t)^3 + 3P_1(1-t)^2t + 3P_2(1-t)t^2 + P_3t^3$$\n", @@ -363,12 +363,12 @@ "\\end{bmatrix}\n", "\\begin{bmatrix}P_0\\\\P_1\\\\P_2\\\\P_3\\end{bmatrix}$$ \n", "\n", - "QuadraticBezier.poly() and Line.poly() are defined similarly." + "`QuadraticBezier.poly()` and `Line.poly()` are [defined similarly](https://en.wikipedia.org/wiki/B%C3%A9zier_curve#General_definition)." ] }, { "cell_type": "code", - "execution_count": 11, + "execution_count": 7, "metadata": { "collapsed": false }, @@ -409,14 +409,23 @@ "cell_type": "markdown", "metadata": {}, "source": [ - "To illustrate the awesomeness of being able to convert our Bezier curve objects to numpy.poly1d objects and back, lets compute the unit tangent vector of the above CubicBezier object, b, at t=0.5 in four different ways.\n", + "The ability to convert between Bezier objects to NumPy polynomial objects is very useful. For starters, we can take turn a list of Bézier segments into a NumPy array \n", + "### Numpy Array operations on Bézier path segments\n", + "[Example available here](https://github.com/mathandy/svgpathtools/blob/master/examples/compute-many-points-quickly-using-numpy-arrays.py)" + ] + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "To further illustrate the power of being able to convert our Bezier curve objects to numpy.poly1d objects and back, lets compute the unit tangent vector of the above CubicBezier object, b, at t=0.5 in four different ways.\n", "\n", - "### Tangent vectors (and more on polynomials)" + "### Tangent vectors (and more on NumPy polynomials)" ] }, { "cell_type": "code", - "execution_count": 12, + "execution_count": 8, "metadata": { "collapsed": false }, @@ -471,7 +480,7 @@ }, { "cell_type": "code", - "execution_count": 13, + "execution_count": 9, "metadata": { "collapsed": false }, @@ -514,7 +523,7 @@ }, { "cell_type": "code", - "execution_count": 14, + "execution_count": 10, "metadata": { "collapsed": false }, @@ -556,7 +565,7 @@ }, { "cell_type": "code", - "execution_count": 15, + "execution_count": 11, "metadata": { "collapsed": false }, @@ -611,7 +620,7 @@ }, { "cell_type": "code", - "execution_count": 16, + "execution_count": 12, "metadata": { "collapsed": false }, @@ -646,7 +655,7 @@ }, { "cell_type": "code", - "execution_count": 17, + "execution_count": 13, "metadata": { "collapsed": false }, diff --git a/README.rst b/README.rst index 967ef53..2646621 100644 --- a/README.rst +++ b/README.rst @@ -1,3 +1,4 @@ + svgpathtools ============ @@ -37,11 +38,6 @@ Some included tools: - compute **inverse arc length** - convert RGB color tuples to hexadecimal color strings and back -Note on Python 3 ----------------- -While I am hopeful that this package entirely works with Python 3, it was born from a larger project coded in Python 2 and has not been thoroughly tested in -Python 3. Please let me know if you find any incompatibilities. - Prerequisites ------------- @@ -85,8 +81,6 @@ Much of the core of this module was taken from `the svg.path (v2.0) module `__. Interested svg.path users should see the compatibility notes at bottom of this readme. -Also, a big thanks to the author(s) of `A Primer on Bézier Curves `_, an outstanding resource for learning about Bézier curves and Bézier curve-related algorithms. - Basic Usage ----------- @@ -117,11 +111,11 @@ information on what each parameter means. on discontinuous Path objects. A simple workaround is provided, however, by the ``Path.continuous_subpaths()`` method. `↩ <#a1>`__ -.. code:: python +.. code:: ipython2 from __future__ import division, print_function -.. code:: python +.. code:: ipython2 # Coordinates are given as points in the complex plane from svgpathtools import Path, Line, QuadraticBezier, CubicBezier, Arc @@ -158,7 +152,7 @@ The ``Path`` class is a mutable sequence, so it behaves much like a list. So segments can **append**\ ed, **insert**\ ed, set by index, **del**\ eted, **enumerate**\ d, **slice**\ d out, etc. -.. code:: python +.. code:: ipython2 # Let's append another to the end of it path.append(CubicBezier(250+350j, 275+350j, 250+225j, 200+100j)) @@ -225,7 +219,7 @@ Reading SVGSs | Note: Line, Polyline, Polygon, and Path SVG elements can all be converted to Path objects using this function. -.. code:: python +.. code:: ipython2 # Read SVG into a list of path objects and list of dictionaries of attributes from svgpathtools import svg2paths, wsvg @@ -262,7 +256,7 @@ convenience function **disvg()** (or set 'openinbrowser=True') to automatically attempt to open the created svg file in your default SVG viewer. -.. code:: python +.. code:: ipython2 # Let's make a new SVG that's identical to the first wsvg(paths, attributes=attributes, svg_attributes=svg_attributes, filename='output1.svg') @@ -294,7 +288,7 @@ over the domain 0 <= t <= 1. that ``path.point(T)=path[k].point(t)``. | There is also a ``Path.t2T()`` method to solve the inverse problem. -.. code:: python +.. code:: ipython2 # Example: @@ -324,11 +318,11 @@ over the domain 0 <= t <= 1. True -Tangent vectors and Bezier curves as numpy polynomial objects -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +Bezier curves as NumPy polynomial objects +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -| Another great way to work with the parameterizations for Line, - QuadraticBezier, and CubicBezier objects is to convert them to +| Another great way to work with the parameterizations for ``Line``, + ``QuadraticBezier``, and ``CubicBezier`` objects is to convert them to ``numpy.poly1d`` objects. This is done easily using the ``Line.poly()``, ``QuadraticBezier.poly()`` and ``CubicBezier.poly()`` methods. @@ -360,9 +354,10 @@ form \end{bmatrix} \begin{bmatrix}P_0\\P_1\\P_2\\P_3\end{bmatrix} -QuadraticBezier.poly() and Line.poly() are defined similarly. +``QuadraticBezier.poly()`` and ``Line.poly()`` are `defined +similarly `__. -.. code:: python +.. code:: ipython2 # Example: b = CubicBezier(300+100j, 100+100j, 200+200j, 200+300j) @@ -392,15 +387,21 @@ QuadraticBezier.poly() and Line.poly() are defined similarly. (-400 + -100j) t + (900 + 300j) t - 600 t + (300 + 100j) -To illustrate the awesomeness of being able to convert our Bezier curve -objects to numpy.poly1d objects and back, lets compute the unit tangent -vector of the above CubicBezier object, b, at t=0.5 in four different -ways. +The ability to convert between Bezier objects to NumPy polynomial +objects is very useful. For starters, we can take turn a list of Bézier +segments into a NumPy array ### Numpy Array operations on Bézier path +segments `Example available +here `__ -Tangent vectors (and more on polynomials) -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +To further illustrate the power of being able to convert our Bezier +curve objects to numpy.poly1d objects and back, lets compute the unit +tangent vector of the above CubicBezier object, b, at t=0.5 in four +different ways. -.. code:: python +Tangent vectors (and more on NumPy polynomials) +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +.. code:: ipython2 t = 0.5 ### Method 1: the easy way @@ -442,7 +443,7 @@ Tangent vectors (and more on polynomials) Translations (shifts), reversing orientation, and normal vectors ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -.. code:: python +.. code:: ipython2 # Speaking of tangents, let's add a normal vector to the picture n = b.normal(t) @@ -472,7 +473,7 @@ Translations (shifts), reversing orientation, and normal vectors Rotations and Translations ~~~~~~~~~~~~~~~~~~~~~~~~~~ -.. code:: python +.. code:: ipython2 # Let's take a Line and an Arc and make some pictures top_half = Arc(start=-1, radius=1+2j, rotation=0, large_arc=1, sweep=1, end=1) @@ -505,7 +506,7 @@ midpoints of the paths from ``test.svg``. We'll need to compute use the ``CubicBezier.length()``, and ``Arc.length()`` methods, as well as the related inverse arc length methods ``.ilength()`` function to do this. -.. code:: python +.. code:: ipython2 # First we'll load the path data from the file test.svg paths, attributes = svg2paths('test.svg') @@ -547,7 +548,7 @@ related inverse arc length methods ``.ilength()`` function to do this. Intersections between Bezier curves ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -.. code:: python +.. code:: ipython2 # Let's find all intersections between redpath and the other redpath = paths[0] @@ -571,7 +572,7 @@ An Advanced Application: Offsetting Paths Here we'll find the `offset curve `__ for a few paths. -.. code:: python +.. code:: ipython2 from svgpathtools import parse_path, Line, Path, wsvg def offset_curve(path, offset_distance, steps=1000): @@ -628,3 +629,4 @@ Licence ------- This module is under a MIT License. + diff --git a/disvg_output.svg b/disvg_output.svg index 818c2cd..280a4c8 100644 --- a/disvg_output.svg +++ b/disvg_output.svg @@ -5,4 +5,4 @@ - \ No newline at end of file +