#!/usr/bin/env python
# coding: utf-8

# ## Turn your notebooks into slideshows

# Press `Space` to proceed.

# You can write a regular Jupyter notebook, with the usual mix of markdown and code cells (keep on pressing `Space`).

# In code cells you press `Shift-Enter` as usual to evaluate your code (but for now press `Space` again).

# In[ ]:


# this is where you press Shift-Enter
import numpy as np
import matplotlib.pyplot as plt
plt.ion()

"Hello world"


# But apart from that, `Space` is your friend!

# You're in a browser, so remember that you can always use smaller / larger fonts with keyboard shortcuts like `Alt +` and `Alt -` or similar (it could be `Ctrl` instead of `Alt` depending on the platform you are on).

# In[ ]:


# of course you can show figures

def polynom(x):
    return 2 * x**2 - 20 * x + 2

X = np.linspace(-10, 10)
Y = polynom(X)
plt.plot(X, Y);


# In[ ]:


# and everything works as usual

# an animation to illustrate 
# translation by variable change
from ipywidgets import interact, FloatSlider

def parabolic(offset):
    X = np.linspace(-10, 10)
    Y = polynom(X-offset)
    # use same y scale for all offsets
    plt.gca().set_ylim([-100, 500])
    plt.plot(X, Y);
    
interact(parabolic, 
         offset=FloatSlider(min=-10., max=10.,
                           step=0.25));


# # The RISE notebook extension

# All this is achieved through the RISE notebook extension.
# 
# See full documentation at http://rise.readthedocs.io/.

# # Thanks to reveal.js

# The underlying tool is [reveal.js](https://revealjs.com/), and it supports a lot of cool features.

# For example you can organize your show into:
# 
# * slides (left to right)
# * subslides (top to bottom)
# * fragments (stops inside a slide)

# You do not need to worry, just press `Space` to proceed along the main line.

# For example this is a subslide; observe the cursor in the bottom right corner.

# If you press `Shift-Space` - here or anywhere else - you will go backwards, so here it would be up.

# # Speaker notes

# If you now press `t` you should see a second window open, with a presenter view, that shows *Notes* cells - that won't show up in the main slides.

# This is an example of a *Notes* cell.

# Next, we'll cover how to tag cells as *Slide*, *SubSlide*, *Fragment* or *Notes*.

# # How to create slideshows

# ### Step 1: enable slideshow cell toolbar

# ![](slide-toolbar.png)

# ### Step 2:  add appropriate tag to each cell

# From the cell toolbar...
# 
# ![](toolbar-options.png)

# or, in command mode, use keyboard shortcuts
# 
# * `shift-i` : toggle slide
# * `shift-b` : toggle subslide
# * `shift-g` : toggle fragment

# # CSS

# 2 files are loaded without the need for configuring
# 
# * `rise.css` in the current directory
# * `README.css` for this notebook because it is called `README.ipynb`
# 
# If that works then the cell below has a large border width and a big south-east border-radius

# In[ ]:


# sample code cell
message = "my look is changed by both rise.css and README.css"


# # Publishing on binder

# In order for a binder-hosted notebook to start in slideshow mode, you need to have the following tag set in the notebook metadata:
# 
# ```javascript        
#     ...
#     "rise": {
#         "autolaunch": true
#     }
#     ...
# ```

# You can edit the notebook metadata from the `edit` menu, submenu `edit notebook metadata`.
# 
# Note finally that the `rise` key in this json file used to be named `livereveal`. The latter is still honored, but the former takes precedence, and it is recommended to use only `rise` from now on.

# # Chalkboard

# As an option, you can turn on the *chalkboard* reveal plugin, that manifests itself with 2 extra buttons in the lower left area, that let you add free drawings on your slides.

# This option is turned on, in the notebook metadata again, with:
# 
# ```javascript
#     ...
#     "rise": {
#       "enable_chalkboard": true
#     }
#     ...
# ```