August 2022
Beginner to intermediate
463 pages
9h 22m
Chinese
Content preview from Tableau Prep即学即用
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166
｜
第
18
章
18.6
详细程度和排名计算
2020.1.3
版本的
Prep Builder
的出现，带来了生成详细程度计算的能力，并将排名
功能引入数据清理步骤中。此前，你必须使用一些变通方法来计算特定级别的数据
汇总，并根据数据集中的度量对类别进行排名。
Level of Detail
（
LOD
，详细程度）计算用于获取某个度量、某个分类字段中的每
个值或整个数据集的汇总数据。这些计算的概念起源于
Tableau Desktop
。通常在
Tableau Desktop
中，度量值会被汇总到视图中最细的维度级别，但经常有用户希望
能自由地指定与自动生成的度量值不同的汇总级别。和
Tableau Desktop
中一样，在
Prep Builder
中，
LOD
计算用于设置度量的汇总级别。这与
Prep Builder
中的汇总步
骤不同，因为它不会改变整个数据集的粒度，而只是改变一个度量。
LOD
计算在第
33
章有更深入的介绍。
Ranking
（排名）计算允许用户根据数据集中的度量标准对数据字段进行排名。该功
能在
Tableau Desktop
中也可使用（作为表计算），并同样由视图中的维度驱动。由
于
Prep Builder
中没有视图，你可能需要将数据集汇总到所要进行排名的粒度。排
名计算在第
34
章有更详细的描述。
LOD
和排名计算都可以通过
Custom Calculation Editor
（自定义计算编辑器）或
Visual Calculation Editor
（可视化计算编辑器）来创建。图
18-13
展示了如何使用可
视化计算编辑器创建 ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.