Positioning annotations with plotnine¶

Drawing annotations with aes(label='colname') and geom_text() can be simple, but positioning them well can be more difficult!

In [24]:

import pandas as pd
from plotnine import *

df = pd.DataFrame([
    { 'name': 'seashells', 'amount': 65, 'price': 14 },
    { 'name': 'sand', 'amount': 40, 'price': 34 },
    { 'name': 'barnacles', 'amount': 23, 'price': 77 }
])
df

import pandas as pd from plotnine import * df = pd.DataFrame([ { 'name': 'seashells', 'amount': 65, 'price': 14 }, { 'name': 'sand', 'amount': 40, 'price': 34 }, { 'name': 'barnacles', 'amount': 23, 'price': 77 } ]) df

Out[24]:

	name	amount	price
0	seashells	65	14
1	sand	40	34
2	barnacles	23	77

The problem¶

By default, your text annotations are centered on the same points that they are annotating

In [25]:

(
    ggplot(df)
    + aes(x='amount', y='price', label='name')
    + geom_point()
    + geom_text()
    + ylim(0, 80)
    + xlim(0, 80)
)

( ggplot(df) + aes(x='amount', y='price', label='name') + geom_point() + geom_text() + ylim(0, 80) + xlim(0, 80) )

Out[25]:

<ggplot: (312216784)>

Moving labels above the points they're annotating¶

To push a label up, use nudge_y. Note that the numbers aren't pixels, but relative to your axis. So if you're plotting large numbers – zero to a million for example – your nudge values will probably be very high.

In [26]:

(
    ggplot(df)
    + aes(x='amount', y='price', label='name')
    + geom_point()
    + geom_text(nudge_y=3)
    + ylim(0, 80)
    + xlim(0, 80)
)

( ggplot(df) + aes(x='amount', y='price', label='name') + geom_point() + geom_text(nudge_y=3) + ylim(0, 80) + xlim(0, 80) )

Out[26]:

<ggplot: (312254016)>

Moving labels next to the points they're annotating¶

To move a label to the left or right, you need to do two things: change the alignment, and then nudge to prevent overlap. This means passing ha='left' or ha='right' to your geom_text, along with a nudge_x that moves your text away from your point.

In [27]:

(
    ggplot(df)
    + aes(x='amount', y='price', label='name')
    + geom_point()
    + geom_text(ha='left', nudge_x=1)
    + ylim(0, 80)
    + xlim(0, 80)
)

( ggplot(df) + aes(x='amount', y='price', label='name') + geom_point() + geom_text(ha='left', nudge_x=1) + ylim(0, 80) + xlim(0, 80) )

Out[27]:

<ggplot: (312291250)>

In [ ]: