My heatmap is blank

还没有人认领这个 Issue。

I am trying to create a heatmap with the follow data: It is a lot of data points, this is just a preview. Any ideas on why it is blank?
```
TF target importance
0 ZIC5 ZIC2 244.284998
1 DLX6 DLX5 146.211550
2 FOXD4L6 FOXD4L3 139.951544
3 DDX43 OOEP 133.502314
4 FOXD4L3 FOXD4L6 132.367859
5 DLX5 DLX6 131.638314
6 FOXD4 FOXD4L1 128.395748
7 HOXA11 HOXA10 112.056258
8 HOXA2 HOXA3 110.962698
9 ZIC2 ZIC5 109.077028
```

CODE BELOW:
```python
import os
import glob
import pickle
import pandas as pd
import numpy as np
import scanpy as sc
import loompy as lp

from dask.diagnostics import ProgressBar

from MulticoreTSNE import MulticoreTSNE as TSNE

import seaborn as sns
import matplotlib.pyplot as plt

df = pd.read_csv("adj.tsv", sep='\t')
print(df.head(10))
df = df.pivot("TF", "target", "importance")
hm = sns.heatmap(df, linewidth = 0.5, cmap = 'coolwarm')
```

从 Python 代码片段开始，重点检查 adj.tsv 的读取、DataFrame 透视以及 seaborn heatmap 调用，并在报告中所述的 Jupyter 设置中重现该问题。输入文件和环境详细信息尚未提供，因此首先确定空白输出是否特定于 ipympl。完成的标准是得到可复现的诊断，或得到一份补充了缺失设置和数据详细信息的明确报告。

由索引模型根据 Issue 内容生成。