Create a subtable from a larger table

Question

Wendy Cameron 2018-6-20

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/406511-create-a-subtable-from-a-larger-table

评论： Peter Perkins 2018-7-3

Matlab example extract table.xls

Hi Everyone, I'm hoping this specific question might be useful too in other more general situations.

I have some sample data attached and want to create some sub-tables from this. How can I look down the Woollybud column and where ever it says "Woolly bud" tabulate the data from the year column and the ACCUM GDD column that coincides with this and create a second table so I get a summary table: Year ACCUM GDD 1999 32 2000 11.75 2001 35.5 and so on

and likewise for the next column Budburst, create a summary table of Year and ACCUM GDD for Budburst?

Much appreciated, Wendy

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Steven Yeh 2018-6-20

2
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/406511-create-a-subtable-from-a-larger-table#answer_325431

在 MATLAB Online 中打开

You can use the readtable function to build a table first, then retrieve the subtable with conditional indexing.

For example:

A = readtable('Matlab example extract table.xls');
w_table = A(A.Woollybud == "Woolly bud", :);
b_table = A(A.Budburst == "Budburst", :);

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

Wendy Cameron 2018-6-20

Thanks very much Stephen that works. If it is a table with many more columns I can then just extract the columns I want. I am slowly learning! Much appreciated.

Kind regards, Wendy

请先登录，再进行评论。

Answer 2

Steven Lord 2018-6-20

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/406511-create-a-subtable-from-a-larger-table#answer_325457

Depending on what you mean by "summary" (compute the average of each table column for each value of your grouping variable, or put all the rows with the same value of your grouping variable together) either groupsummary or sortrows may be of use to you.

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

Peter Perkins 2018-7-3

As Steve says, it's often possible to do "groupwise" calculations without actually splitting up your data. If you have a lot of different groups, it's much easier that way.

请先登录，再进行评论。