extracting the median of a boxplot

hie. i have 6 boxplot figures like what i have attached to this post. all i want is to extract the median values of each box in the first subplot of each figure. can anybody help pls?

Answer 1

[Star Strider]

From the documentation:

• boxplot creates a visual representation of the data, but does not return numeric values. To calculate the relevant summary statistics for the sample data, use the following functions: {In the documentation, the function list follows}

So, to get the median of the first box in a particular plot, do something like this:

Data = randn(100, 10);
Median_1 = median(Data(:,1));

figure(1)
boxplot(Data);
grid

[zahra zol]

Thank u Strider. i was actually trying to find a way to determine the median by taking some handle or sth like that to the boxplots themselves. but i guess its is either really hard or impossible. i did as u said and it worked. thanks for caring.

[Star Strider]

My pleasure.

I did my best to use findobj to get the median (as the documentation for boxplot suggests), but I could not make it work. Apparently it is only possible to use findobj to change specific properties of boxplot.

[Songbai Ji]

Actually, boxplot returns a list of handles that you can ues to retreive the data:

t = rand(100,1);

hd = boxplot(t);

Now hd is a 7-by-1 array. You can check:

get(hd(1))

etc. to see what data it provides -- check the "tag" field. There should be one that gives median (use 'ydata').

I think boxplot will be able to remove outliers. Directly getting median from data does not.

You can also use findobj to retreive the handle:

hd = findobj('tag', 'Median');

then:

get(hd)