Rotation of Axis Labels

The angle parameter in element_text() function allows to rotate the text.

Note: currently this only works for axis labels, i.e. for axis_text, axis_text_x, axis_text_y parameters in theme().

import pandas as pd

from lets_plot import *

LetsPlot.setup_html()
LetsPlot.set_theme(theme_light())

df = pd.read_csv('https://raw.githubusercontent.com/JetBrains/lets-plot-docs/master/data/midwest.csv')
df["state"] = df["state"].map({
    "IL": "Illinois",
    "IN":" Indiana",
    "MI": "Michigan",
    "OH": "Ohio",
    "WI": "Wisconsin",
})
print(df.shape)
df.head()

(437, 29)

	Unnamed: 0	PID	county	state	area	poptotal	popdensity	popwhite	popblack	popamerindian	...	percollege	percprof	poppovertyknown	percpovertyknown	percbelowpoverty	percchildbelowpovert	percadultpoverty	percelderlypoverty	inmetro	category
0	1	561	ADAMS	Illinois	0.052	66090	1270.961540	63917	1702	98	...	19.631392	4.355859	63628	96.274777	13.151443	18.011717	11.009776	12.443812	0	AAR
1	2	562	ALEXANDER	Illinois	0.014	10626	759.000000	7054	3496	19	...	11.243308	2.870315	10529	99.087145	32.244278	45.826514	27.385647	25.228976	0	LHR
2	3	563	BOND	Illinois	0.022	14991	681.409091	14477	429	35	...	17.033819	4.488572	14235	94.956974	12.068844	14.036061	10.852090	12.697410	0	AAR
3	4	564	BOONE	Illinois	0.017	30806	1812.117650	29344	127	46	...	17.278954	4.197800	30337	98.477569	7.209019	11.179536	5.536013	6.217047	1	ALU
4	5	565	BROWN	Illinois	0.018	5836	324.222222	5264	547	14	...	14.475999	3.367680	4815	82.505140	13.520249	13.022889	11.143211	19.200000	0	AAR

5 rows × 29 columns

highlight_axis_labels = theme(
    text=element_text(color='gray', size=13), 
    axis_text=element_text(color='blue')
)

1. Default Axis Labels Layout

p = ggplot(df) + geom_jitter(aes("state", "poptotal"), color='gray75', seed=42)
p

2. Layout Labels for Discrete Axis

Let’s change rotation angle to check placement of labels on a discrete axis. Labels on y-axis are removed for this demo.

2.1. Horizontal Axis

p_x_both = p + theme(axis_text_y=element_blank()) + scale_x_discrete(position="both")

gggrid([
    p_x_both + theme(axis_text_x=element_text(angle=10)) + highlight_axis_labels + ggtitle("10°"),
    p_x_both + theme(axis_text_x=element_text(angle=90)) + highlight_axis_labels + ggtitle("90°")
])

2.2. Vertical Axis

When the rotation angle is set to 90°, some labels are not displayed to avoid overlapping.

gggrid([
    p_x_both + coord_flip() + theme(axis_text_x=element_text(angle=10)) + highlight_axis_labels + ggtitle("10°"),
    p_x_both + coord_flip() + theme(axis_text_x=element_text(angle=90)) + highlight_axis_labels + ggtitle("90°")
]) + ggsize(1000, 300)

3. Layout Labels for Continuous Axis

For continuous axis the number of labels varies depending on how many it can fit.

3.1. Horizontal Axis

Changing the angle of rotation changes the number of labels on the axis: 90° rotation allows to place more labels on the horizontal axis.

p_y_both = p + theme(exponent_format=['e', -8, 8], axis_text_x=element_blank()) + scale_y_continuous(position="both")

gggrid([
    p_y_both + coord_flip() + theme(axis_text=element_text(angle=10)) + highlight_axis_labels + ggtitle("10°"),
    p_y_both + coord_flip() + theme(axis_text=element_text(angle=90)) + highlight_axis_labels + ggtitle("90°")
])

3.2. Vertical Axis

By changing the angle of rotation, thereby increasing the label heights, we get a reduction in the total number of labels on the vertical axis.

gggrid([
    p_y_both + theme(axis_text=element_text(angle=10)) + highlight_axis_labels + ggtitle("10°"),
    p_y_both + theme(axis_text=element_text(angle=90)) + highlight_axis_labels + ggtitle("90°")
])