Matlab won't plot a graph of my data?

I'm currently plotting a simple data table of excel data (a 12445 by 8 table where the first column is the x axis and the rest of the columns are multiple plots on the same graph (using the hold on function) Now I've had this issue before but this time I just can't seem to shake it - not sure if it's a glitch. I broke the code down from the more efficient script I wrote to see whether I could place breakpoints and see where the issue lay. So far I have:

    x = KAcConcentrationsat130K.WaveNumber(2:12445);
    y2 = KAcConcentrationsat130K.VarName2(2:12445);
    figure
    plot(x,y2)
    title('KCH_3COO Varying Concentrations at 130K')
    xlabel('Frequency (cm^-^1)')
    ylabel('Absorbance')
    hold on
    y3 = KAcConcentrationsat130K.VarName3(2:12445);
    plot(x,y3)

However, MATLAB does not plot the graph. No figure windows come up and instead it just prints every integer value of data (atleast 12000 values) out in the command window. Has anyone got an idea of how to stop it from printing the data out in the command window and plot it instead?

[Rik]

What is the output of which plot?

[Nicola Fairbairn]

I'm not sure what you mean?

[Rik]

I suspect that something overwrote the internal plot function, so by running the line of code below, you can find out if this is the case.

which plot

Answer 1

[Image Analyst]

In the command window, do this:

>> which -all plot

Tell us what you see. You might see this:

>> which -all plot
built-in (C:\Program Files\MATLAB\R2017b\toolbox\matlab\graph2d\plot)
C:\Program Files\MATLAB\R2017b\toolbox\matlab\polyfun\@polyshape\plot.m      % polyshape method
C:\Program Files\MATLAB\R2017b\toolbox\matlab\polyfun\@alphaShape\plot.m     % alphaShape method
C:\Program Files\MATLAB\R2017b\toolbox\matlab\bigdata\@tall\plot.m           % tall method
C:\Program Files\MATLAB\R2017b\toolbox\matlab\graphfun\@graph\plot.m         % graph method
C:\Program Files\MATLAB\R2017b\toolbox\matlab\graphfun\@digraph\plot.m       % digraph method
C:\Program Files\MATLAB\R2017b\toolbox\signal\signal\@dspdata\plot.m         % dspdata method
C:\Program Files\MATLAB\R2017b\toolbox\stats\classreg\@LinearModel\plot.m    % LinearModel method
C:\Program Files\MATLAB\R2017b\toolbox\matlab\timeseries\@timeseries\plot.m  % timeseries method

If you see anything that says plot is a variable, that's a problem because it means that you made a variable with the same name as a crucial built-in function and it's using that variable instead of the built-in function. And since you didn't put the semicolon at the end of the line, it's printing all the values to the command window.

Or you could put that line of code directly into your script, before you call plot(), and see what it prints out. From the sounds of it, chances are high that you defined a variable called plot. Search for everywhere in your code that you used plot by typing control-shift-f.

[Nicola Fairbairn]

>> which -all plot
built-in (C:\Program Files\MATLAB\R2017b\toolbox\matlab\graph2d\plot)
C:\Program Files\MATLAB\R2017b\toolbox\matlab\datatypes\@tabular\tabular.m   % tabular method
C:\Program Files\MATLAB\R2017b\toolbox\matlab\polyfun\@polyshape\plot.m      % polyshape method
C:\Program Files\MATLAB\R2017b\toolbox\matlab\polyfun\@alphaShape\plot.m     % alphaShape method
C:\Program Files\MATLAB\R2017b\toolbox\matlab\bigdata\@tall\plot.m           % tall method
C:\Program Files\MATLAB\R2017b\toolbox\matlab\graphfun\@graph\plot.m         % graph method
C:\Program Files\MATLAB\R2017b\toolbox\matlab\graphfun\@digraph\plot.m       % digraph method
C:\Program Files\MATLAB\R2017b\toolbox\signal\signal\@dspdata\plot.m         % dspdata method
C:\Program Files\MATLAB\R2017b\toolbox\stats\classreg\@LinearModel\plot.m    % LinearModel method
C:\Program Files\MATLAB\R2017b\toolbox\matlab\timeseries\@timeseries\plot.m  % timeseries method

is what I got

[Image Analyst]

OK, but since you said in your "Answer" that it no longer happens, my guess is that you had somehow created a variable called plot. Then, when you did it later, that variable was no longer in the workspace and so it used the built-in plot function instead of your variable and so it worked. The recommendation is to not name variables using names of built-in functions.

[Nicola Fairbairn]

The issue has come back again, my problem is I can't identify what variable it doesn't like. My code is only 5 or 6 lines:

plot(NaTFAcooling.WaveNumber(2:14933), NaTFAcooling{2:14933, 2:end});
set(gca, 'XDir','reverse');
title('NaTFA cooling Ramp')
xlabel('Frequency (cm^-^1)')
ylabel('Absorbance')

My thoughts are the that the thing it doesn't like is the fact that apart from WaveNumber, the other columns are called "VarName2","VarName3" etc. which were automatically assigned on importing the data. I'll change them and see what I get. Thanks in advance.

[Nicola Fairbairn]

So I've changed the column variables and nothing has fixed. It seemed to run fine on a different computer in the lab, not sure whether its a glitch. There is nothing in the Workspace with a generic name. Thoughts?

[Walter Roberson]

When you say the issue has come back, do you mean your code is displaying a bunch of data as indicated in your original post?

In order for the current code to be displaying a bunch of data, NaTFAcooling.WaveNumber would have to be a function that displayed data, or else title or xlabel or ylabel would have to be something different than their normal function. It would not be enough for plot to have become a variable as you have the semi-colon at the end of the line that would block output; the same for set

Answer 2

[Nicola Fairbairn]

I took out some unnecessary data that I didn't need (I only really cared about 4000 rows of the 12000) and it seemed to work yesterday, I will run it tomorrow and let you know what happens.

Answer 3

[Eddie Murray]

Why Do I Get This When I Try To Run A Graph In MATLAB

Warning: An error occurred while drawing the scene: Could not find node in peer tree during reparentChildren

Warning: An error occurred while drawing the scene: Could not find node in peer tree during replaceCamera

Warning: An error occurred while drawing the scene: Could not find node in peer tree during reparentChildren

Warning: An error occurred while drawing the scene: Could not find node in peer tree during replaceChild

Warning: An error occurred while drawing the scene: Could not find node in peer tree during replaceChild

Warning: An error occurred while drawing the scene: Could not find node in peer tree during reparentChildren

Warning: An error occurred while drawing the scene: Could not find node in peer tree during replaceChild

Warning: An error occurred while drawing the scene: Could not find node in peer tree during replaceChild

Warning: An error occurred while drawing the scene: Could not find node in peer tree during reparentChildren

Warning: An error occurred while drawing the scene: Could not find node in peer tree during replaceChild

Warning: An error occurred while drawing the scene: Could not find node in peer tree during replaceChild

Warning: An error occurred while drawing the scene: Could not find node in peer tree during reparentChildren

Warning: An error occurred while drawing the scene: Could not find node in peer tree during replaceChild

Warning: An error occurred while drawing the scene: Could not find node in peer tree during replaceChild

Warning: An error occurred while drawing the scene: Could not find node in peer tree during reparentChildren

Warning: An error occurred while drawing the scene: Could not find node in peer tree during replaceChild

Warning: An error occurred while drawing the scene: Could not find node in peer tree during replaceChild

Warning: An error occurred while drawing the scene: Could not find node in peer tree during reparentChildren

Warning: An error occurred while drawing the scene: Could not find node in peer tree during replaceChild

Warning: An error occurred while drawing the scene: Could not find node in peer tree during replaceChild

Warning: An error occurred while drawing the scene: Could not find node in peer tree during reparentChildren

Warning: An error occurred while drawing the scene: Could not find node in peer tree during replaceChild

Warning: An error occurred while drawing the scene: Could not find node in peer tree during replaceChild

Warning: An error occurred while drawing the scene: Could not find node in peer tree during reparentChildren

Warning: An error occurred while drawing the scene: Could not find node in peer tree during replaceChild

Warning: An error occurred while drawing the scene: Could not find node in peer tree during replaceChild

Warning: An error occurred while drawing the scene: Could not find node in peer tree during reparentChildren

Warning: An error occurred while drawing the scene: Could not find node in peer tree during replaceChild

Warning: An error occurred while drawing the scene: Could not find node in peer tree during replaceChild

Warning: An error occurred while drawing the scene: Error in json_scenetree: Could not find node in replaceChild

Warning: An error occurred while drawing the scene: Error in json_scenetree: Could not find node in replaceChild

[Image Analyst]

Probably an error in the program you wrote.

If you have any more questions, then attach your data and code to read it in with the paperclip icon after you read this:

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