Creating multiple plots from a data file using a for loop

Hi all,

I am very new to Matlab, and I am trying to plot multiple figures from a dataset using a for loop.

However, it's not working and I don't how to solve it.

The idea is that the loop plots 42 different figures (one for each participant), and that the first figure contains the data from the 1:14 row from columns 3 (x-axis) and column 5 (reaction times), figure 2 should contain the data from the 15:28 row from columns 3 (x-axis) and column 5 (y-axis), etc..

Below is the code that I have used:

Thai_UniversalPictures_Categorization = readtable('Thai_UniversalPictures_Categorization.xlsx'); % This is the table with the data

figure;
hold on;
 
for i = 1 : 14 : 588(Thai_UniversalPictures_Categorization); % I would like 42 figures
    x = Thai_UniversalPictures_Categorization(i:1+13, 3); % The x-axis should contain the picture's names, which are located in the third column of the data file. The i:1+13 was written as an attempt to tell the code it's a loop and that it should take the first 14 pictures' names for the first figure, the next 14 pictures for the second figure etc. 
    y = Thai_UniversalPictures_Categorization(1:1+13, 5); % The y-axis should contain reaction times , which are located in the fifth column of the data file. The i:1+13 was written as an attempt to tell the code it's a loop and that it should take the first 14 reaction times for the first figure, the next 14 reaction times for the second figure etc. 
    plot(x,y);
end

I get an error which says:

Error using tabular/plot

Too many input arguments.

Error in outlierplots (line 11)

plot(x,y);

I hope you can follow my explanation and help me.

Best regards, Anne

[KSSV]

Tell us what does

whos x y 

shows up?

[Anne Reuten]

It says this:

Name Size Bytes Class Attributes

x 14x1 3196 table

y 14x1 1272 table

[KSSV]

YOu cannot input table to plot.....you can access the data data using:

x.(1) 
y.(1)

But note that, your tables are of different size......to plot, the data should be of same size.

[Anne Reuten]

Thank you for your help, but I don't really understand what you mean.

If I just type this:

plot(Thai_UniversalPictures_Categorization{1:14, 5})

The figure shows up and I get no error message.

That data is still accessed from a table, but no error message?

Also, the tables' size are both 14x1 right?

[Anne Reuten]

I have adapted the code to this:

Thai_UniversalPictures_Categorization = readtable('Thai_UniversalPictures_Categorization.xlsx');
 
%% Reaction time
 
for i = 1 : 14 : 588(Thai_UniversalPictures_Categorization);
    figure; 
    hold on;
    plot(Thai_UniversalPictures_Categorization{i:1+13, 5}); title('Reactiontime');
end

It is now creating 42 figures, but only the first one contains data (from the first 14 rows) and the others are empty.

[Anne Reuten]

I think I managed to get it working correctly.

In case someone else is trying to do a similar thing and is struggling, I used this code:

Thai_UniversalPictures_Categorization = readtable('Thai_UniversalPictures_Categorization.xlsx');
 
%% Reaction time
 
for i = 1 : 14 : 588(Thai_UniversalPictures_Categorization);
    figure; 
    hold on;
    plot(Thai_UniversalPictures_Categorization{i:i+13, 5}); title('Reactiontime');
end

Answer 1

[Guillaume]

I see you've solved your problem, but for future reference the problem had nothing to do with plot. The problem was with your incorrect use of indexing.

() indexing on a table returns a portion of a table as a table

{} indexing on a table returns a portion of the content of the table as whatever type that content is.

Alternatively, you can use . indexing to get a particular variable of the table, so

plot(sometable(:, somecolumn), sometable(:, someothercolumn))

is never going to work as you are passing tables to plot

plot(sometable{:, somecolumn}, sometable{:, someothercolumn})
or
plot(sometable.nameofsomecolumn, sometable.nameofsomeothercolumn)

is the correct syntax.

[Anne Reuten]

Thank you very much for your explanation!

Answer 2

[KALYAN ACHARJYA]

plot(x',y');

Answer 3

[Shubham Sangle]

You can use this,

() indexing on a table returns a portion of a table as a table

plot(table(:, column1), table(:, column2))