Reorder x-axis bar graph categorical

Hi all,

I have viewed some of the other suggestions on here, but none have worked for me and I'm unsure where I am going wrong. I am trying to reorder a bar graph to be in the order I have specified in my variable cats.

errlow_ERP =  [young_mid_parietal_PMconcept_stderr_ERP old_mid_parietal_PMconcept_stderr_ERP MCI_mid_parietal_PMconcept_stderr_ERP];
ERP_mean = [young_mid_parietal_PMconcept_mean_ERP old_mid_parietal_PMconcept_mean_ERP MCI_mid_parietal_PMconcept_mean_ERP];
errhigh_ERP =  [young_mid_parietal_PMconcept_stderr_ERP old_mid_parietal_PMconcept_stderr_ERP MCI_mid_parietal_PMconcept_stderr_ERP];
cats = categorical({'Young','Older adult','MCI'});
subplot(3,4,12)
hold on;
p = bar(cats,ERP_mean,...
    'FaceColor',[0.75,0.75,0.75],...
    'EdgeColor','k',...
    'LineWidth',1.5,...
    'BaseValue',0);
baseline = p.BaseLine;
er = errorbar(cats,ERP_mean,errlow_ERP,errhigh_ERP,'.','vertical');
set(gca,'LineWidth',1,'FontSize',14)
ylim([0 8.5])
er.LineWidth = 1.5;
er.Color = 'k';
er.MarkerSize = 1;
xlabel('Group','FontSize',16)
ylabel('Amplitude in \muV','FontSize',16)

Any advice is greatly appreciated!

Answer 1

[Adam Danz]

Starting in MATLAB R2023b, bar accepts string arrays in addition to categoricals in the x-argument. The bar order will maintain the string order.

str = ["Young","Older adult","MCI"];
y = 1:3;
bar(str, y)

For releases prior to R2023b, you can reorder the categories using reordercats().

I know it doesn't look intuitive because the order specified by reordercats is the same as the original order but this sets that order in stone.

figure
cats = categorical({'Young','Older adult','MCI'});
cats = reordercats(cats,{'Young','Older adult','MCI'}); 
p = bar(cats, y);