How do I assign a value to a particular column in a subsection of a table?

Question

Karen 2017-5-9

1
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/339549-how-do-i-assign-a-value-to-a-particular-column-in-a-subsection-of-a-table

评论： Peter Perkins 2017-5-10

Using the example testing data on https://www.mathworks.com/help/matlab/matlab_prog/calculations-on-tables.html, I would like to write something like

T(T.Gender=='female',:).Test2 = 100

I can do something similar with array data, but get an error with table data. Is there a simple way to make this work without having to create a dummy array of the appropriate length for my constant value?

    T = readtable(fullfile(matlabroot,'examples','matlab','testScores.csv'),...
                  'ReadRowNames',true)
    T.Gender = categorical(T.Gender)
    % select a subset of the rows
    rows = T.Gender=='female'
    % this works, and is my usual way of working with array data
    A = table2array(T(:,2:4))
    A(rows,2) = 100
    % This works, but is ugly
    T(rows,:).Test2 = 100 * ones(size(T(rows,:).Test2))
    % This does not work  
    T(rows,:).Test2 = 100