August 2022
Beginner to intermediate
463 pages
9h 22m
Chinese
Content preview from Tableau Prep即学即用
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232
｜
第
26
章
26.2
为什么使用分组
分组是你需要学习的技术，原因是多方面的。
26.2.1
提高准确率
当听到
Data
（数据）这个词时，大多数人似乎想到的是系统生成的数据被输入数据库。
经过一年的数据分析，大多数数据工作者都会认为自己是幸运的，可以和这样的数
据打交道
!
人们使用的大部分数据源仍然是人工编制的。即使是领先的股票研究机
构，也是通过人工输入
PDF
中的企业业绩来建立所要分析的数据源。问题就在于此。
手工输入数据会增加打错字母或数字的风险。再加上现代社会任务期限驱动的文化
氛围，你看到的可能是一个非常混乱的数据集。如果你没有投资于自动生成的数据，
你可能也没有一个资源丰富的
IT
团队来清理这些错误。幸运的是，分组可以让你把
不正确和正确的值组合在一起，形成一个完全正确的数据集。
26.2.2
数据层次结构导向
在你从事的数据相关的工作中很可能听到过“钻研数据”这种说法。这是指从数据
的高层次（粒度较小）视图开始，逐渐关注低层次（粒度较大）的视图，通常是通
过过滤掉不感兴趣的内容，以保持数据集的可管理性。像
Tableau
这样的工具中的
层次结构允许你对数据这样“向下钻”，但层次结构并不总是存在于数据中。你可
以通过使用组来缓解这种情况，在你的数据集中的现有数据字段之间建立更高的或
中间的层次。常见的层次结构可能包括：
•
时间（年、月、周、日等）。
•
地理（国家、州、城市等）。
•
组织（办公室、部门、团队等）。
•
操作流程（呼叫中心、团队、产品）。
组可以用来将低级实体拉到一起，创建一个新的更高级别的实体 ...
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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.