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

# # Title of my notebook
# 
# Some text.
# 
# ![Photo of Galilei's manuscript](https://upload.wikimedia.org/wikipedia/commons/b/b3/Galileo_Galilei_%281564_-_1642%29_-_Serenissimo_Principe_-_manuscript_with_observations_of_Jupiter_and_four_of_its_moons%2C_1610.png)
# 
# $E = mc^2$

# In[1]:


def arithmetic_mean(sequence):
    s = 0.0
    for element in sequence:
        s += element
    n = len(sequence)
    return s / n


# In[2]:


arithmetic_mean([1, 2, 3, 4, 5])


# In[3]:


# this is here for google colab to update altair
import altair as alt
if not alt.__version__.startswith("5"):
    get_ipython().run_line_magic('pip', 'install altair==5.3.0')


# In[4]:


# this example is from https://altair-viz.github.io/gallery/layered_histogram.html

import pandas as pd
import altair as alt
import numpy as np
np.random.seed(42)

# Generating Data
source = pd.DataFrame({
    'Trial A': np.random.normal(0, 0.8, 1000),
    'Trial B': np.random.normal(-2, 1, 1000),
    'Trial C': np.random.normal(3, 2, 1000)
})

alt.Chart(source).transform_fold(
    ['Trial A', 'Trial B', 'Trial C'],
    as_=['Experiment', 'Measurement']
).mark_bar(
    opacity=0.3,
    binSpacing=0
).encode(
    alt.X('Measurement:Q').bin(maxbins=100),
    alt.Y('count()').stack(None),
    alt.Color('Experiment:N')
)