How to reorder a categorical axis?

I am ploting a set of values aginst an categorical array, however the the categorical axis always appears in the alphabetical order, how can I control the order it appears?

here's an example

x = categorical({'a','b','c','d','e'});

y = [1:5];

scatter(x,y);

how do I plot y aginst x so the x-axis appears in a non-alphabetical order, like b-e-d-a-c.

thanks!

Answer 1

[Dave B]

Three options to change the order, depending on where you want to change it:

Option 1: You can use reordercats to re-order the categories:

x = categorical({'a','b','c','d','e'});
y = 1:5;
orderedx = reordercats(x,{'b' 'e' 'd' 'a' 'c'});
scatter(orderedx ,y);

Or you can pass in the order as an input to categorical:

x = categorical({'a','b','c','d','e'}, {'b' 'e' 'd' 'a' 'c'});
y = 1:5;
scatter(x,y);

Or you can change the order on the axes using the Categories property of the CategoricalRuler:

x = categorical({'a','b','c','d','e'});
y = 1:5;
scatter(x,y);
xaxis=get(gca,'XAxis');
xaxis.Categories={'b' 'e' 'd' 'a' 'c'};

[VBBV]

% Fourth option is you can use find to get indices for array and pass it to
% xticklabels
x = categorical({'a','b','c','d','e'});
new_x = {'b','e','d','a','c'};
for k = 1:length(x)
    idx(k) = find(new_x(k) == x);
end
y = 1:5;
scatter(x,y(idx));
xticklabels(x(idx))

% strange output using scatter
x(idx)  

ans = 1×5 categorical array
     b      e      d      a      c 

%  even though idx values are substituted, when i use it scatter function
%  it still retains old order
scatter(x(idx),y(idx))

[Zhe Dong]

Many thanks, it helps!