* [![DOI](https://zenodo.org/badge/284307852.svg)](https://zenodo.org/badge/latestdoi/284307852)
* [dual project: sketches repository](https://github.com/gbrault/jupytersketches.git)

![Gallery](fig/JupyterPySketcher.png)

## jupytersketcher

Tool for creating sketches of physics problems in terms of Python code. This work is based upon [pysketcher](https://github.com/hplgit/pysketcher) originally developped by HPL [see Wikipedia](https://en.wikipedia.org/wiki/Hans_Petter_Langtangen).

Note: Use the term Pysketcher as jupytersketcher in this documentation

- current [![Binder](https://mybinder.org/badge_logo.svg)](https://mybinder.org/v2/gh/gbrault/jupytersketcher.git/master?filepath=notebooks%2FDryFriction.ipynb)
- morning snapshot  [![Binder](https://mybinder.org/badge_logo.svg)](https://mybinder.org/v2/git/https%3A%2F%2Fgogs.seadev.online%2Fgbrault%2Fjupytersketcher/master)

## Differences compared to Pysketcher

The main goals are:
- make a Jupyter Notebook and Lab compatible version. We do not plan to support the standalone version
- allow 'simulation' inside Jupyter
- define a yaml simplified syntax to create sketches [grammar rail-road](https://www.bottlecaps.de/rr/ui)
- increment basic classes to support our goals

### Install

use pip install git+https://\<server url> as no release in PyPI yet (nor planned)

### Purpose

Pysketcher can typically be used to draw figures like

<!-- <img src="doc/src/tut/fig-tut/wheel_on_inclined_plane.png" width=600> -->
![](doc/src/tut/fig-tut/wheel_on_inclined_plane.png)

Such figures can easily be *interactively* made using a lot of drawing
programs.  A Pysketcher figure, however, is defined trough
computer code. This gives a great advantage: geometric features can be
parameterized in terms of variables. Geometric variations are then
trivially generated. Also, complicated figures can be built as a
hierarchy of simpler elements.  The figure can easily be made to move
according to, e.g., a solution of a differential equation.

Here is a very simple figure that illustrates how geometric features are
parameterized by variables (H, R, L, etc.):

<!-- <img src="doc/src/tut/fig-tut/vehicle0_dim.png" width=600> -->
![](doc/src/tut/fig-tut/vehicle0_dim.png)

One can then quickly change parameters, below to
`R=0.5; L=5; H=2` and `R=2; L=7; H=1`, and get new figures that would be
tedious to draw manually in an interactive tool.

<!-- <img src="doc/src/tut/fig-tut/vehicle_v23.png" width=800> -->
![](doc/src/tut/fig-tut/vehicle_v23.png)

Another major feature of Pysketcher is the ability to let the
sketch be dynamic and make an animation of the time evolution.
Here is an example of a very simple vehicle on a bumpy road,
where the solution of a differential equation (upper blue line) is fed
back to the sketch to make a vertical displacement of the spring and
other objects in the vehicle. [View animation](http://hplgit.github.io/bumpy/doc/src/mov-bumpy/m2_k1_5_b0_2/index.html) (the animation was created by
[this Pysketcher script](https://github.com/hplgit/bumpy/blob/master/doc/src/fig-bumpy/bumpy_road_fig.py)).

<!-- <img src="http://hplgit.github.io/bumpy/doc/src/mov-bumpy/m2_k1_5_b0_2/tmp_frame_0030.png" width=600> -->
![](http://hplgit.github.io/bumpy/doc/src/mov-bumpy/m2_k1_5_b0_2/tmp_frame_0030.png)


### Tutorial

For an introduction to Pysketcher, see the tutorial in [HTML](http://hplgit.github.io/pysketcher/doc/pub/tutorial/pysketcher.html), [Sphinx](http://hplgit.github.io/pysketcher/doc/pub/tutorial/html/index.html), or [PDF](http://hplgit/github.io/pysketcher/doc/pub/tutorial/pysketcher.pdf) format (or a simplified version of
the tutorial in Chapter 9 in [A Primer on Scientific Programming with Python](http://www.amazon.com/Scientific-Programming-Computational-Science-Engineering/dp/3642549586/ref=sr_1_2?s=books&ie=UTF8&qid=1407225588&sr=1-2&keywords=langtangen), 4th-5th edition, by H. P. Langtangen, Springer, 2014-2016).

### Examples

See the `examples` directory for some examples beyond the more basic
ones in the tutorial.
For example, an elastic beam can be sketched as

<!-- <img src="fig/beam2_3.png" width=600> -->
![](fig/beam2_3.png)

The sketch was created by the program [`examples/beam2.py`](https://github.com/hplgit/pysketcher/tree/master/examples/beam2.py).

Here is an illustration of the idea of numerical integration:

<!-- <img src="fig/integral_noncomic_strip.png" width=800> -->
![](fig/integral_noncomic_strip.png)

As shown in the figure-generating program [`examples/integral_comic_strip.py`](https://github.com/hplgit/pysketcher/tree/master/examples/integral_comic_strip.py),
this illustration can easily be turned into an [XKCD](http://xkcd.com) type of comic strip:

<!-- <img src="fig/integral_comic_strip.png" width=800> -->
![](fig/integral_comic_strip.png)

### Technology

Pysketcher applies Matplotlib to make the drawings, but it should be quite
straightforward to replace the backend `MatplotlibDraw.py` by similar code
utilizing TikZ or another plotting package.

The core of the Pysketcher software is a thin layer basically
constructing a tree structure of elements in the sketch. A lot of
classes are offered for different type of basic elements, such as
Circle, Rectangle, Text, Text with arrow, Force, arbitrary curve, etc.
Complicated figures can be created by sticking one figure into another
(i.e., hierarchical building of figures by sticking one tree structure
into another).

### Install

Pysketcher is pure Python code and
works with Python version 2 and 3. Just do the standard


```
Terminal> sudo python setup.py install
```

Pysketcher demands installation of the following packages:

 * Matplotlib (`sudp pip install matplotlib`)
 * Future (`sudo pip install future`)
 * NumPy (`sudo pip install numpy`)

The `Spline` object in Pysketcher also requires SciPy (`sudo pip install scipy`).

### Citation

If you use Pysketcher and want to cite it, you can either cite this
web site or the book
that has the original documentation of the tool.

BibTeX format:


```
@book{Langtangen_Primer_2016,
  title = {A Primer on Scientific Programming With {P}ython},
  author = {H. P. Langtangen},
  year = {2016},
  publisher = {Springer},
  edition = {Fifth},
}

@misc{Pysketcher,
  title = {{P}ysketcher: {D}rawing tool for making sketches},
  author = {H. P. Langtangen},
  url = {https://github.com/hplgit/pysketcher},
  key = {Pysketcher},
  note = {\url{https://github.com/hplgit/pysketcher}},
  year = 2016,
}
```

Publish format:


```
* books
** A Primer on Scientific Programming With {P}ython
   key:       Langtangen_Primer_2016
   author:    H. P. Langtangen
   year:      2016
   publisher: Springer
   status:    published
   edition:   Fifth
   entrytype: book
* misc
** {P}ysketcher: {D}rawing tool for making sketches
   key:       Pysketcher
   author:    H. P. Langtangen
   url:       https://github.com/hplgit/pysketcher
   status:    published
   sortkey:   Pysketcher
   note:      \url{https://github.com/hplgit/pysketcher}
   year:      2016
```

### History

Pysketcher was first constructed as a powerful educational example on
object-oriented programming for the book
*A Primer on Scientific Programming With Python*, but the tool quickly
became so useful for the author that it was further developed and
heavily used for creating figures in other documents.

