Calculating and add the std error bar from the mean values

Hi everyone

I have data vector (named: Mean_data) representing the mean of 6 different treatments. I already plotted this Mean_data as a bar graph, but I would like to add the std error bar on the top of each bar. My question is, how can I calculate the std error bar from the mean that I have already got and plot it on the top of each bar.

here is my code and data.

Mean_data=[20.43 8.61 15.37 2.70 29.09 31.59];
% Create figure
figure('Color',[1 1 1]);

% Create axes
axes1 = axes;
hold(axes1,'on');

% Create bar
bar(Mean_data,'DisplayName','Photosynthesis','FaceColor',[0 0 1],...
    'BarWidth',0.4);

% Create ylabel
ylabel('µmol m⁻² s⁻¹','FontSize',15);

% Create title
title({'Average of response to each treatment'});

hold(axes1,'off');
% Set the remaining axes properties
set(axes1,'FontSize',12,'FontWeight','bold','XColor',[0 0 0],'XGrid','on',...
    'XTick',[1 2 3 4 5 6],'XTickLabel',...
    {'treatment1','treatment2','treatment3','treatment4','treatment5','treatment6'},...
    'YColor',[0 0 0],'YGrid','on','ZColor',[0 0 0]);

Thanks in advance

Answer 1

[Scott MacKenzie]

You can't calculate the standard error from the means. You need the raw data. If the raw data (used to calculate the means) are in a matrix M, then the standard error vector is

se = std(M) / sqrt(size(M,1));