# Matplotlib Exercise 2

## Imports

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%matplotlib inline
import matplotlib.pyplot as plt
import numpy as np

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## Exoplanet properties

Over the past few decades, astronomers have discovered thousands of extrasolar planets. The following paper describes the properties of some of these planets.

http://iopscience.iop.org/1402-4896/2008/T130/014001

Your job is to reproduce Figures 2 and 4 from this paper using an up-to-date dataset of extrasolar planets found on this GitHub repo:

https://github.com/OpenExoplanetCatalogue/open_exoplanet_catalogue

A text version of the dataset has already been put into this directory. The top of the file has documentation about each column of data:

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Use `np.genfromtxt` with a delimiter of `','` to read the data into a NumPy array called `data`:

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data = np.genfromtxt('open_exoplanet_catalogue.txt' , delimiter = ",")

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assert data.shape==(1993,24)

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Make a histogram of the distribution of planetary masses. This will reproduce Figure 2 in the original paper.

• Customize the box, grid, spines and ticks to match the requirements of this data.
• Pick the number of bins for the histogram appropriately.
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mass = data[:2]

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assert True # leave for grading

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Make a scatter plot of the orbital eccentricity (y) versus the semimajor axis. This will reproduce Figure 4 of the original paper. Use a log scale on the x axis.

• Customize the box, grid, spines and ticks to match the requirements of this data.
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raise NotImplementedError()

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assert True # leave for grading

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