Altair 图表仅将数据保存到 html 这实际上是 plot 的一部分

Question

When creating a chart using altair , I like the fact that I can save it to .html containing all the data in the plot.使用altair创建图表时，我喜欢可以将其保存到包含.html中所有数据的 .html 的事实。 However, also the columns of a pd.DataFrame that are not plotted are stored in the .html file.但是， pd.DataFrame中未绘制的列也存储在.html文件中。

I am in a situation, where my data frame has roughly 100 columns but only ~5 of them are part of the plot.我的情况是，我的数据框大约有 100 列，但其中只有约 5 列是 plot 的一部分。 Thus I'd like to be able to only save those columns in the plot that are actually used, decreasing the file size of the .html by a factor 20.因此，我希望能够只保存实际使用的 plot 中的那些列，从而将.html的文件大小减小 20 倍。

Here's an MWE:这是一个MWE：

import numpy as np
import pandas as pd
import altair as alt

mwe_df = pd.DataFrame(
    {
        "x": np.arange(10),
        "y": np.random.randn(10),
        "z": np.random.randn(10),
    }
)

chart = alt.Chart(mwe_df).mark_line().encode(
    x="x",
    y="y"
)
chart.save("mwe.html")

The resulting file mwe.html looks like this生成的文件mwe.html看起来像这样

<!DOCTYPE html>
<html

// I cut a lot of code away to show the important part

<body>
  <div id="vis"></div>
  <script>
    (function (vegaEmbed) {
        
        // I cut a lot of code away to show the important part

        "datasets": {
          "data-f268207ac55fefac2d4e472cf850ebe3": [{
            "x": 0,
            "y": 0.5499788508261615,
            "z": -1.477946005772743 // Don't want this here
          }, {
            "x": 1,
            "y": 0.6200551442726329,
            "z": 0.857375723129614 // Don't want this here
          }, {
            "x": 2,
            "y": 2.162997199610359,
            "z": 0.8528682789795423 // Don't want this here
          }, 

        // I cut a lot of code away to show the important part

     
     
</body>

</html>

I could of course only hand a subset of the data frame to altair , ie by calling alt.Chart(mwe_df[["x","y"]]) but this seems a bit cumbersome.我当然只能将数据帧的一个子集交给altair ，即通过调用alt.Chart(mwe_df[["x","y"]])但这似乎有点麻烦。

Is there a way to tell altair to only save the relevant columns in the .html ?有没有办法告诉altair只保存.html中的相关列？

Answer 1

I also think this would be a useful feature to have in Altair, but there are some considerations with implementing it.我也认为这将是 Altair 中的一个有用功能，但在实施它时需要考虑一些事项。 You can follow preliminary work and discussion in this PR https://github.com/altair-viz/altair/pull/2586 .您可以在此 PR https://github.com/altair-viz/altair/pull/2586中关注初步工作和讨论。 In addition of what is mentioned there, it is possible that something might be offered via VegaFusion ( https://vegafusion.io/ ) in the future as it covers some of the same things as the altair_transform package.除了那里提到的内容之外，将来可能会通过 VegaFusion ( https://vegafusion.io/ ) 提供某些内容，因为它涵盖了与 altair_transform package 相同的内容。

Altair 图表仅将数据保存到 html 这实际上是 plot 的一部分

问题描述

1 个解决方案

解决方案1
0 2022-09-13 18:47:53

Altair 图表仅将数据保存到 html 这实际上是 plot 的一部分

问题描述

1 个解决方案

解决方案1 0 2022-09-13 18:47:53

解决方案1
0 2022-09-13 18:47:53