Plotting groups of different size separately, also error message: Vectors must be the same length

Hello!

I tried plotting some data and got the 'Error using plot. Vectors must be the same length.' error message.

I am trying to plot two sets of data:

G: 0.66, 0.05, 0.51, 0.4

B: 0.15, 0.03, 0.10, 0.62, 0.002, 0.10, 0.07, 0.2

using the following line of code: plot([1 2],[G; B], 'MarkerSize',15)

I know the error message is because the two groups are of different sizes, but is there a way to tell matlab that they are not paired, I just want them separate, but I want them plotted in that format?

Thanks!

Vyte

Answer 1

[Image Analyst]

You have 2 values for x (1 and 2) but you have 4 values in the G vector and 8 values in the B vector. Please give a complete list of all (x,y) coordinates that you'd like to plot.

G = [0.66, 0.05, 0.51, 0.4] % A 1 by 4 row vector.

G = 1×4

0.6600 0.0500 0.5100 0.4000

B = [0.15, 0.03, 0.10, 0.62, 0.002, 0.10, 0.07, 0.2]  % A 1 by 8 row vector.

B = 1×8

0.1500 0.0300 0.1000 0.6200 0.0020 0.1000 0.0700 0.2000

y = [G; B] % Concatenate B below G vertically. (Won't work because # columns is different in the two row vectors).

Error using vertcat
Dimensions of arrays being concatenated are not consistent.

plot([1 2],[G; B], 'MarkerSize',15)

[Vyte Jan]

@Image Analyst maybe this will help, this is an example of what I am trying to plot. Just data points in space, and in separate parts of the graph.

I will always have a different number of G vs B, because I have less good outcome patients.

Is there another way to plot this data?

[Image Analyst]

I thought I solved that for you in your related question:

https://www.mathworks.com/matlabcentral/answers/1795290-plotting-data-on-binary-axis-and-draw-lines-between-points#answer_1042270

[Vyte Jan]

@Image Analyst Yes exactly its very similar!

In the previous question that was paired regions, so both x and y had identical number of values, and they needed to be joined by a line.

This time, I will never have equal number of values (B will always be greater then G) and they are not paired. I cant seem to find a function that would allow me to plot them in that exact format as in: https://www.mathworks.com/matlabcentral/answers/1795290-plotting-data-on-binary-axis-and-draw-lines-between-points#answer_1042270

but of different size groups.

I came across this post: https://tex.stackexchange.com/questions/460722/how-to-make-a-categorical-grouped-scatterplot called Categorical Grouped Scatterplot, but again they seemed to be using an equal number of variables.

Is it only possible to plot groups with equal numbers?

[Vyte Jan]

This is what I get if I plot G and B separately using 'hold on' function, the problem is they cover each other so I cant see the overall distribution in the two groups. And the legend isnt working.

[Stephen23]

https://www.mathworks.com/help/matlab/ref/scatter.html

[Image Analyst]

markerSize = 40;
G = [0.66, 0.05, 0.51, 0.4]; % A 1 by 4 row vector.
B = [0.15, 0.03, 0.10, 0.62, 0.002, 0.10, 0.07, 0.2];  % A 1 by 8 row vector.
plot(ones(1, numel(G)), G, '.', 'MarkerSize', markerSize)
hold on
plot(2 * ones(1, numel(B)), B, '.', 'MarkerSize', markerSize)
xlim([0, 2.5])
grid on;
xticklabels({'', '', 'G', '', 'B'})

[Vyte Jan]

@Image Analyst Thats perfect!! exactly what I was looking for!

If its not too much can I ask how does plot(ones(1, numel(G)), G actually work?

I understand numel(G) extarcts the size of the variable G which is 7 and those values are plotted as '1' using G as a vector in space? so B is done in the same way but by multiplying the vector space by 2 it shifts the whole graph to the right.

Thank you very much for your help!

[Image Analyst]

For every y value you must have an x value so the ones just makes sure of that. It creates a vector of all 1's since all of the G's are to be plotted with the same x value, not different ones. Same for B -- I made it 2 so it's apart from the G dots.

[Vyte Jan]

Makes sense! Thank you for your help and the explanation :)