Create a subtable from a larger table

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

Answer 1

[Steven Yeh]

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", :);

[Wendy Cameron]

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

Answer 2

[Steven Lord]

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.

[Peter Perkins]

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.