Arrangement of pie charts using matplotlib subplot

Question

I have 7 pi-charts (4 are listed below). I am trying to create a dashboard with 4 pie charts in first row and 3 pie charts in second row. Not sure where I am going wrong with the below code. Are there any other alternatives to achieve this? Any help would be appreciated.

from matplotlib import pyplot as PLT
fig = PLT.figure()
ax1 = fig.add_subplot(221)
line1 = plt.pie(df_14,colors=("g","r"))
plt.title('EventLogs')
ax1 = fig.add_subplot(223)
line2 = plt.pie(df_24,colors=("g","r"))
plt.title('InstalledApp')
ax1 = fig.add_subplot(222)
line3 = plt.pie(df_34,colors=("g","r"))
plt.title('Drive')
ax1 = fig.add_subplot(224)
line4 = plt.pie(df_44,colors=("g","r"))
plt.title('SQL Job')
ax1 = fig.add_subplot(321)
line5 = plt.pie(df_54,colors=("g","r"))
plt.title('Administrators')
ax2 = fig.add_subplot(212)
PLT.show()

Solution

A better method which I always use and is more intuitive, at-least for me, is to use subplot2grid....

fig = plt.figure(figsize=(18,10), dpi=1600)
#this line will produce a figure which has 2 row 
#and 4 columns 
#(0, 0) specifies the left upper coordinate of your plot
ax1 = plt.subplot2grid((2,4),(0,0))
plt.pie(df_14,colors=("g","r"))
plt.title('EventLogs')
#next one
ax1 = plt.subplot2grid((2, 4), (0, 1))
plt.pie(df_24,colors=("g","r"))
plt.title('InstalledApp')

And you can go on like this, and when you want to switch the row just write the coordinate as (1, 0)... which is second row-first column.

An example with 2 rows and 2 cols -

fig = plt.figure(figsize=(18,10), dpi=1600)
#2 rows 2 columns

#first row, first column
ax1 = plt.subplot2grid((2,2),(0,0))
plt.pie(df.a,colors=("g","r"))
plt.title('EventLogs')

#first row sec column
ax1 = plt.subplot2grid((2,2), (0, 1))
plt.pie(df.a,colors=("g","r"))
plt.title('EventLog_2')

#Second row first column
ax1 = plt.subplot2grid((2,2), (1, 0))
plt.pie(df.a,colors=("g","r"))
plt.title('InstalledApp')

#second row second column
ax1 = plt.subplot2grid((2,2), (1, 1))
plt.pie(df.a,colors=("g","r"))
plt.title('InstalledApp_2')

Hope this helps!

Comments

[user3447653]

Thanks, it works perfectly. Is there a way to set a common legend for all the 7 plots? For example, red as "Not healthy", green as "Healthy"?

[hashcode55]

You are looking for figlegend, but as each of the plots have their own axes, its not possible to do it with legend directly. Or why not just position your legend for one plot?

[user3447653]

I tried this but not working as expected: lgd = plt.legend((line1), ('Helathy','Not Healthy'), loc='upper right')

[Josh Friedlander]

This answer, and subplot2grid, deserve much more attention. For such a basic task, subplots in Matplotlib are one of the most frustrating things I have to deal with. Bookmarking for future use!