Changing the rotation of tick labels in Seaborn heatmap

Question

I'm plotting a heatmap in Seaborn. The problem is that I have too many squares in my plot so the x and y labels are too close to each other to be useful. So I'm creating a list of xticks and yticks to use. However passing this list to the function rotates the labels in the plot. It would be really nice to have seaborn automatically drop some of the ticks, but barring that I would like to be able to have the yticks upright. ``` import pandas as pd import numpy as np import seaborn as sns data = pd.DataFrame(np.random.normal(size=40*40).reshape(40,40)) yticks = data.index keptticks = yticks[::int(len(yticks)/10)] yticks = ['' for y in yticks] yticks[::int(len(yticks)/10)] = keptticks xticks = data.columns keptticks = xticks[::int(len(xticks)/10)] xticks = ['' for y in xticks] xticks[::int(len(xticks)/10)] = keptticks sns.heatmap(data,linewidth=0,yticklabels=yticks,xticklabels=xticks) ```

Accepted Answer

`seaborn` uses `matplotlib` internally, as such you can use `matplotlib` functions to modify your plots. I've modified the code below to use the `plt.yticks` function to set `rotation=0` which fixes the issue.

```
import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
import seaborn as sns

data = pd.DataFrame(np.random.normal(size=40*40).reshape(40,40))

yticks = data.index
keptticks = yticks[::int(len(yticks)/10)]
yticks = ['' for y in yticks]
yticks[::int(len(yticks)/10)] = keptticks

xticks = data.columns
keptticks = xticks[::int(len(xticks)/10)]
xticks = ['' for y in xticks]
xticks[::int(len(xticks)/10)] = keptticks

sns.heatmap(data,linewidth=0,yticklabels=yticks,xticklabels=xticks)

# This sets the yticks "upright" with 0, as opposed to sideways with 90.
plt.yticks(rotation=0)

plt.show()
```

Changing the rotation of tick labels in Seaborn heatmap

Solution

Problem