Plot only specific categorical values / scatterplot

Using idexing. But with categories you also need to set which categories should appear on the axes (last line in demo). Otherwise, even with indexing, all categories will display in the plot, even if they do not contain y-values due to indexing.

Demo 1

T = table(repelem(categorical(num2cell(char(65:70))),1,2)', randi(10,12,1),'VariableNames',{'Shop','Sales'})

T = 12×2 table

Shop Sales ____ _____ A 5 A 5 B 4 B 6 C 7 C 10 D 3 D 3 E 5 E 2 F 8 F 7

selection = categorical({'A','B','D'});

idx = ismember(T.Shop, selection);

scatter(T.Shop(idx), T.Sales(idx),90,'filled')

ax = gca();

ax.XAxis.Categories = selection; % Set which categories appear

Demo 2

After adding the answer, I realized that indexing isn't really required but if you have many data points, indexing might help to speed up the process and reduce the size of the figure in memory since it only plots the data you want rather than plotting all of the data and then making only some of it visible like this approach does below.

T = table(repelem(categorical(num2cell(char(65:70))),1,2)', randi(10,12,1),'VariableNames',{'Shop','Sales'})
scatter(T.Shop, T.Sales,90,'filled')
ax = gca();
ax.XAxis.Categories = categorical({'A','B','D'});

If you want to change the visible categories you don't need to reproduce the plot, you just need to call this last line again with the selected categories.