Question :
I have a temperature file with many years temperature records, in a format as below:
2012-04-12,16:13:09,20.6
2012-04-12,17:13:09,20.9
2012-04-12,18:13:09,20.6
2007-05-12,19:13:09,5.4
2007-05-12,20:13:09,20.6
2007-05-12,20:13:09,20.6
2005-08-11,11:13:09,20.6
2005-08-11,11:13:09,17.5
2005-08-13,07:13:09,20.6
2006-04-13,01:13:09,20.6
Every year has different numbers, time of the records, so the pandas datetimeindices are all different.
I want to plot the different year’s data in the same figure for comparing . The X-axis is Jan to Dec, the Y-axis is temperature. How should I go about doing this?
Answer #1:
Although Chang’s answer explains how to plot multiple times on the same figure, in this case you might be better off in this case using a groupby and unstacking:
(Assuming you have this in dataframe, with datetime index already)
In [1]: df
Out[1]:
value
datetime
2010-01-01 1
2010-02-01 1
2009-01-01 1
# create additional month and year columns for convenience
df['Month'] = map(lambda x: x.month, df.index)
df['Year'] = map(lambda x: x.year, df.index)
In [5]: df.groupby(['Month','Year']).mean().unstack()
Out[5]:
value
Year 2009 2010
Month
1 1 1
2 NaN 1
Now it’s easy to plot (each year as a separate line):
df.groupby(['Month','Year']).mean().unstack().plot()
Answer #2:
Try:
ax = df1.plot()
df2.plot(ax=ax)
Answer #3:
If you a running Jupyter/Ipython notebook and having problems using;
ax = df1.plot()
df2.plot(ax=ax)
Run the command inside of the same cell!! It wont, for some reason, work when they are separated into sequential cells. For me at least.
Answer #4:
To do this for multiple dataframes, you can do a for loop over them:
fig = plt.figure(num=None, figsize=(10, 8))
ax = dict_of_dfs['FOO'].column.plot()
for BAR in dict_of_dfs.keys():
if BAR == 'FOO':
pass
else:
dict_of_dfs[BAR].column.plot(ax=ax)
Answer #5:
Just to enhance @adivis12 answer, you don’t need to do the if statement. Put it like this:
fig, ax = plt.subplots()
for BAR in dict_of_dfs.keys():
dict_of_dfs[BAR].plot(ax=ax)
