accessing table data in different forms

Question

Ege 2014-10-25

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https://ww2.mathworks.cn/matlabcentral/answers/160081-accessing-table-data-in-different-forms

回答： Ege 2014-10-26

Hi I have T table as follows.

LastName = {'Smith';'Johnson';'Williams';'Jones';'Brown'};
Age = [38;43;38;40;49];
FirstName = {'Amanda' ;'Brenda';'Carl'; 'Denis'; 'Ethan'};
Something = {'String1' ;'String2';'String2'; 'String1'; 'String5'};
Weight = [176;163;131;133;119];
FavoriteColor = {'blue' ;'red' ;'yellow'; 'orange' ;'colorblind' };
T = table(Age,FirstName,Weight,FavoriteColor,Something,'RowNames',LastName)
T.FavoriteColor= categorical(T.FavoriteColor);
T.Something= categorical(T.Something);

when I use

A=T(:,5);

I get a variable A which is a table as well. But when I use

A=T.Something;

I get a variable A which is a categorical value like the ones is column Something. I want to use loops so I need to use the first one with indices but I want the result in the second one. What should I do?

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Geoff Hayes 2014-10-25

Ege - what are you trying to achieve? You mention that you want to use loops, but what do you want to use the loops for?

Ege 2014-10-25

在 MATLAB Online 中打开

Well I just started the project I will use it for many things but for now, I have divided my dataset into 2 tables which holds categorical and non categorical data. I'm currently using the categorical one and try to implement a histogram on that since usual histogram function does not work on categorical data. My dataset is huge so at first I will use the categorical column of the T table I mentioned in the question. When I use it like below, it works fine.

a=T.Something;
hist=zeros(size(a,1),1);
u=unique(a);
for i=1: size(a,1)
    for j=1: size(u,1)
        if isequal(a(i),u(j))
            hist(j)=hist(j)+1;
        end
    end
end
for i=1:numel(hist,1)
    if isequal(hist(i),0)
        hist(i)=[];
    end
end
histogram = table(u(:),hist(:));