I have 8 columns in my result.csv, and need to add legend to the line graph I have. My code is:
per_data=genfromtxt('result.csv',delimiter=',')
plt.plot(per_data)
plt.xlabel ('x stuff')
plt.ylabel ('y stuff')
plt.title('my test result')
plt.grid()
plt.show()
it gives me:
how can I add a legend which happened to be the title row in my csv file?
If you use the names=True option to np.genfromtxt, it will read in the first line of the .csv as the column names.
For example:
import matplotlib.pyplot as plt
import numpy as np
# Make dummy csv file for this example
from io import StringIO
result_csv = StringIO(u"""
xstuff, data1, data2, data3
0, 1, 2, 3
1, 1, 3, 4
2, 2, 1, 3
3, 1, 2, 5
""")
# Read in csv. Use names=True to also store column headers
per_data=np.genfromtxt(result_csv,delimiter=',',names=True)
# Loop over columns. Here I assume you have the x-data in the first column, so skip that one
for name in per_data.dtype.names[1:]:
# Set the line's label to the column name
plt.plot(per_data['xstuff'],per_data[name],label=name)
# Add a legend
plt.legend(loc=0)
plt.xlabel ('x stuff')
plt.ylabel ('y stuff')
plt.title('my test result')
plt.grid()
plt.show()
