Question

"Using Python, code to find the smallest and largest planet mass (if known), and plot these as two curves against the year of discovery"

Basically looking to use data from an excel sheet where 'disc_year' and 'pl_mass' are columns of data; and code Python to find the maximum value of mass and the minimum value of mass for each year, then plot this as two curves. There are multiple planets for any given year hence multiple values for mass. Below is example of what data might be.

Example data: Mass - 5.5, 0.2, 6, 56, 209, 0.3, 44, 124, 403, 98, 304, 202, 11.7, 5.4, 17.8, 21.9, 603.3, 108.2, 19, 0.3

Year - 2019, 2019, 1994, 2002, 2001, 2016, 1994, 2019, 2002, 2001, 2016, 2015, 2015, 1999, 2002, 1999, 1999, 2015, 2001, 2016

Answer 1

import pandas as pd

# creating a dataframe

df = pd.DataFrame([(5.5,2019),

(0.2,2019),

(6, 1994),

(56,2002),

(209,2001),

(0.3,2016),

(44,1994),

(124,2019),

(403,2002),

(98,2001),

(304,2016),

(202,2015),

(11.7,2015),

(5.4,1999),

(17.8,2002),

(21.9,1999),

(603.3,1999),

(108.2,2015),

(19,2001),

(0.3,2016)],

columns =('pl_mass', 'disc_year'))

print(df)

grouped_df = df.groupby("disc_year") #group by disc_year

maximums = grouped_df.max() #finding maximum value of pl_mass

maximums = maximums.reset_index() #resetting index and creating a dataframe for maximum pl_mass with year for plotting

print(maximums)

grouped_df = df.groupby("disc_year") #group by disc_year

minimums = grouped_df.min() #finding mainimum value of pl_mass

minimums = minimums.reset_index() #resetting index and creating a dataframe for minimum pl_mass with year for plotting

print(minimums)

import matplotlib.pyplot as plt

# line 1 points

x1 = maximums["disc_year"]

y1 = maximums["pl_mass"]

# plotting the line 1 points

plt.plot(x1, y1, label = "Maximum")

# line 2 points

x2 = minimums["disc_year"]

y2 = minimums["pl_mass"]

# plotting the line 2 points

plt.plot(x2, y2, label = "Minimum")

# naming the x axis

plt.xlabel('Discovery Year')

# naming the y axis

plt.ylabel('PLT_MASS')

# giving a title to my graph

plt.title('Comparison Curve')

# show a legend on the plot

plt.legend()

# function to show the plot

plt.show()

To use data directly form excel sheet you can try the following piece of code :

Import pandas as pd

Df = pd.real_excel("name_of_file.xlsx")

Or directly create a data frame as shown in the above code.