How do I get multiple boxplots onto one figure, with NaNs in the mix?

Hi,

I've been trying to get 3 plots on one figure and have mostly gotten there, but my code keeps throwing the error: "G must be the same length as X or the same length as the number of columns in X," even though these 2 variables are the same lengths. I can't help but think it's the NaNs, even though I've read that boxplot treats them correctly. Code to follow:

First, I created these vectors as I am compiling group data and generating a mean. With that mean, I want to plot in terms of the scalae (which is the ST, SM, and SV variables).

meanampST = [meanampST peakmeanST]; meanampSM = [meanampSM peakmeanSM]; meanampSV = [meanampSV peakmeanSV];

After those are filled:

group = [ones(size(meanampST));2*ones(size(meanampSM)); 3*ones(size(meanampSV))]; x = cat(1,meanampST,meanampSM,meanampSV); boxplot(x,group);

..and then I get the error. For reference:

x =

    0.1043    0.1488       NaN    0.0628    0.1959    0.2604    0.0674    0.0477
    0.2905    0.2177    0.0814    0.0793    0.3609    0.1885       NaN    0.0478
       NaN       NaN    0.0671    0.1126       NaN       NaN       NaN    0.1584

group =

     1     1     1     1     1     1     1     1
     2     2     2     2     2     2     2     2
     3     3     3     3     3     3     3     3

UGGH! Thank you so much!

Answer 1

[Kelly Kearney]

Just a small change needed:

boxplot(x(:), group(:))

[Lindsay]

Ah, that worked!

Can I ask why this fixes it? I'm trying to learn as much as I can and would love to have a better understanding.

Also, how do I add things like colors? Is it the same as with the regular plot function? Thanks!

Thank you so much Kelly! You made my day!

[Kelly Kearney]

From the help:

boxplot(X,G) specifies one or more grouping variables G, producing a separate box for each set of X values sharing the same G value or values. Grouping variables must have one row per element of X, or one row per column of X. Specify a single grouping variable in G by using a vector, a character array, a cell array of strings, or a vector categorical array; specify multiple grouping variables in G by using a cell array of these variable types, such as {G1 G2 G3}, or by using a matrix. If multiple grouping variables are used, they must all be the same length. Groups that contain a NaN or an empty string ('') in a grouping variable are omitted, and are not counted in the number of groups considered by other parameters.

so you can get your desired plot via a few syntaxes:

boxplot(x')
boxplot(x(:), group(:))
boxplot(x', group(:,1))

(Though that last one would only be useful if you wanted to rearrange the order the boxes were displayed).

As for colors, you can set them via the 'colors' input parameter:

h = boxplot(x', 'colors', 'rgb')

or you can alter all the line properties by returning the handles, as I did above (you can see which handle corresponds to which part of the boxplot by looking at their Tag properties).

[daniel sand]

Thank you Kelly, great answer.

Answer 2

[Haijun Deng]

boxplot(x','ori','horizontal')