title: Plotly: How to round display text in annotated heatmap but keep full format on hover?
body: <p>I am drawing a correlation matrix of the Titanic dataset.</p>
  <pre><code>df_corr = df.corr()
  </code></pre>
  <p>Originally, the matrix looks like this:</p>
  <pre><code>fig = ff.create_annotated_heatmap(
              z=df_corr.to_numpy(),
              x=df_corr.columns.tolist(),
              y=df_corr.index.tolist(),
              zmax=1, zmin=-1,
              showscale=True,
              hoverongaps=True
              )
  # add title
  fig.update_layout(title_text='&lt;i&gt;&lt;b&gt;Correlation not round&lt;/b&gt;&lt;/i&gt;')
  </code></pre>
  <p><a href="https://i.stack.imgur.com/ohB5C.png" rel="noreferrer"><img src="https://i.stack.imgur.com/ohB5C.png" alt="not_round" /></a></p>
  <p>I want to round the float number, so they display less digits after the <code>.</code> dot.</p>
  <p>The current workaround is actually round the pandas dataframe before input.</p>
  <pre><code>df_corr_round = df_corr.round(3)
  fig = ff.create_annotated_heatmap(
              z=df_corr_round.to_numpy(),
              x=df_corr.columns.tolist(),
              y=df_corr.index.tolist(),
              zmax=1, zmin=-1,
              showscale=True,
              hoverongaps=True
              )
  # add title
  fig.update_layout(title_text='&lt;i&gt;&lt;b&gt;Correlation round&lt;/b&gt;&lt;/i&gt;')
  </code></pre>
  <p><a href="https://i.stack.imgur.com/UB0Wn.png" rel="noreferrer"><img src="https://i.stack.imgur.com/UB0Wn.png" alt="round" /></a></p>
  <p>But the workaround also rounds the text when I hover mouse over. I want hover text in full detail while display text are round.</p>
  <p>Can I display less digits on each cell without changing the input dataframe ?</p>