how to solve this error index?

i Have five files i have to plot 50 percentile plot column 3 data with respect to 120:0.1:150.5 in one single plot

Files = dir('*.csv');
Filesc = struct2cell(Files);
NrFiles = size(Filesc,2);
for k = 1:NrFiles
    filename = Filesc{1,k};
    T{k,:} = readtable(filename);
    end
Final_T = cat(1,T{:});
i=reshape(Final_T.r,5,24)   

i = 5×24

1.0e+65 * 0.0000 0.0000 0.0000 -0.0000 0.0000 0.0000 0.0000 -0.0000 -0.0000 -0.0000 0.0000 0.0000 0.0000 0.0001 1.0400 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 -0.0000 0.0000 -0.0000 0.0000 -0.0000 0.0000 -0.0000 0.0000 0.0000 0.0000 -0.0000 -0.0000 -0.0000 0.0000 0.0000 0.0000 0.6970 1.1500 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 -0.0000 0.0000 -0.0000 0.0000 -0.0000 -0.0000 -0.0000 0.0000 0.0000 0.0000 -0.0000 -0.0000 -0.0000 0.0000 0.0000 0.0000 0.7700 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 -0.0000 -0.0000 0.0000 -0.0000 0.0000 -0.0000 -0.0000 0.0000 0.0000 0.0000 0.0000 -0.0000 -0.0000 0.0000 0.0000 0.0000 0.0000 0.8510 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 -0.0000 0.0000 0.0000 -0.0000 0.0000 -0.0000 -0.0000 0.0000 0.0000 0.0000 -0.0000 -0.0000 -0.0000 0.0000 0.0000 0.0000 0.0000 0.9410 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 -0.0000 0.0000 -0.0000 -0.0000

i(:)'

ans = 1×120

0.8142 0.7521 0.6826 0.6062 0.5238 0.4362 -0.3673 -0.2726 -0.1752 -0.0760 0.0239 0.1236 -0.1978 -0.2947 -0.3886 -0.4787 -0.5639 -0.6435 0.6993 0.7671 0.8273 0.8793 0.9224 0.9564 0.7131 0.8761 1.0706 1.3118 1.6262 2.0632

size(i)

ans = 1×2

5 24

x=120:0.2:124.6;
size(x)

ans = 1×2

1 24

per=prctile(i,50) % i hv to take 50 percentile of column 3 data from all the files and plot against 120:0.1:120.5

per = 1×24

1.0e+64 * 0.0000 -0.0000 -0.0000 -0.0000 0.0000 0.0000 0.0000 -0.0000 -0.0000 -0.0000 0.0000 0.0000 0.0004 7.7000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 -0.0000 -0.0000 0.0000 -0.0000

figure
plot(x, per)                         
grid
xlabel('b')
ylabel('r')

i am not able to plot properly 50 percentile plot for column 3 data which is present in all data files wrt 120:0.1:124.6 in one single plot . i want all the files data in one plot

[Star Strider]

This looks strikingly similar to how to import file? and I still do not understand the objective.

[ramya]

this time data s changed i have to plot 50 percentile column 3 data of all files wrt 120:0.1:124.6

Answer 1

[Rahul]

Hi ramya,,

I understand that you’re trying to plot 50 percentile plots of 3rd column data of five .csv files, onto a single plot.

Given your current code snippet, you can generate 50-percentile plot vectors of column data from each file using ‘prctile’ function and then plot against the desired x-axis limits onto a single figure using ‘hold’ command, as shown below:

% Reshape final table to get column data vectors 
Final_T=reshape(Final_T.r,24,5); 
% Desired x-axis limits 
xRange = 120:0.1:150.5; 
percentiles = zeros(length(xRange), 5); 

for i = 1:length(NrFiles) 
    
    % Extract the third column 
    column3Data = Final_T(:, i); 
    
    % Calculate the 50th percentile for the current dataset 
    percentiles(:, i) = prctile(column3Data, 50) 
end 

figure; 
for i = 1:size(percentiles, 2) 
    % Plot individual column percentiles
    plot(xRange, percentiles(:, i), 'DisplayName', ['File ', num2str(i)]); 
    hold on;
end 

Here is the resultant figure with five 50-percentile plots, indicated using legends:

For more information regarding custom n-percentile plots of datasets, refer to the documentation link mentioned below:

https://in.mathworks.com/help/matlab/ref/prctile.html