How I can plot 7 graphs on the same X,Y axes

I am trying to plot 7 graphs on the same axes. I am using hold on, hold off syntax, but every time it plots only 3 graphs, not the rest. (They all are same and the error line giving is, "Error in Flood_analyzer (line 146) plot(thour, Flood_Area_Tot4);").

I am using a student version, so I am curious whether it has certain datapoint limit in the graphs. (Each graph has 108 (x,y) points).

plot(thour, Flood_Area_Tot1);
hold on
plot(thour, Flood_Area_Tot2);
%hold on
plot(thour, Flood_Area_Tot3);
%hold on
plot(thour, Flood_Area_Tot4);
%hold on
plot(thour, Flood_Area_Tot5);
%hold on
plot(thour, Flood_Area_Tot6);
%hold on
plot(thour, Flood_Area_Tot7);
hold off

The output is...(Only 3 graphs..Why??? :( )

[dpb]

The Mathworks FAQ says there's no difference in functionality for the student version of MATLAB so the answer is undoubtedly in the data.

It would be easier if you hadn't made seven different variables of what should be one array of Flood_Area_Total; then if you orient by column you could just write

plot(thour, Flood_Area_Total)

and get all seven lines at once.

However, given the observation, try the following exercise at the command line --

sum(isfinite([Flood_Area_Tot1(:) Flood_Area_Tot2(:) Flood_Area_Tot3(:) Flood_Area_Tot4(:) ...
              Flood_Area_Tot5(:) Flood_Area_Tot6(:) Flood_Area_Tot7(:)])

which will return the number of elements in each column that are not NaN or Inf that the plot() command silently ignores.

Given the symptoms, it's likely you're going to find the last four columns are all NaN; something went wrong on the import from file or otherwise generating the values.

That's what the crystal is saying...and it's just back from the repair shop (yet again)...

[DGM]

It's only plotting 3 graphs because it's halting with an error once it tries to plot the fourth. Without knowing what the error actually says, I can only guess. Since we're all guessing at missing information, I'm going to put my money on Flood_Area_Tot4 not being the same length as thour -- or not existing at all.

[Tharindu Manamperi]

Thank you, @DGM and @dpb. I went through the files separately and strangely foundout that 4th file has 1 timestep less, as you both pointed out. I truely can't imagine why is that. Anyway, Is there any method That I can still plot all graphs in the same axes?

So in summary, what I have is, Flood Area Tot1-3 and Flood Area Tot5-7 has 108 time steps and Flood Area Tot4 only has 107 time steps.

Thank you?

(Without that file I was able to generate all plots successfully)

[DGM]

Not knowing why it's 1 sample shorter, it's hard to say how to correct it exactly. One can't know if they span the same interval with 1 fewer samples, or if it has the same resolution but is missing the first or last sample.

Regardless, if there are 19000 samples, I doubt it matters for the purpose of the plot. You could just plot it versus thour(1:end-1) and any offset would probably be visually imperceptible.

[dpb]

As DGM notes, the difference on a plot is probably imperceptible, but if one is doing an analysis, as my grandpa used to say, "If going to do it, might as well do it right!" :)

So, the question then is back to where did the data traces come from and how did you load them? If they came from separate files, it's likely one file didn't have as many points in it as another/the others--if the time is recorded in the file as well, then read it along with the data to keep the two in synch for each file; don't make the blanket assumption that all are the same length that your present code does.

If they are all zero-based and one is just short an observation at the beginning or end, then you can still put them altogether in a single array; just augment the shorter one with a NaN element at the proper place to retain alignment or all traces with each other. This, of course, does presume that the time sample rates are the same across all files as your code above assumes. From the plot you do have, that certainly does appear to be a fair assumption, but we can't know for sure without the data files.