MATLAB: Trying to create a loop for for opening data files and plotting them

dataloopwhile loop

this is the code I have so far. The part in the loop is from code I wrote for just one of the files. I want to change it so that a different file is opened with each loop but i'm not sure how. Thanks for any help
maxit=42;
i=1;
while i < maxit
  A = textscan(fopen('7633_Flux_AmeriFluxFormat_3.dat'),'%f %f %f %f %f %f %f %f %f %f %f %f %f %f %s %s %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %s %s %f %f %f %f %f %f %f %f', 'Delimiter',',','Headerlines',1);
  A_time = A{1,1};
  B_time = num2str(A_time);
  x = datenum(B_time,'yyyymmddHHMM');
  CO2 = A{1,3};
  H2O = A{1,5};
  FC = A{1,7};
  LE = A{1,9};
  ET = A{1,11};
  H = A{1,13};
  G = A{1,15};
  SG = A{1,16};
  WD = A{1,21};
  WS = A{1,22};
  ZL = A{1,25};
  TA1 = A{1,36};
  TA2 = A{1,39};
  RH1 = A{1,37};
  RH2 = A{1,40};
  VPD = A{1,42};
  SWin = A{1,52};
  SWout = -A{1,53};
  LWin = A{1,54};
  LWout = -A{1,55};
  ALB = A{1,50};
    figure()
    plot(x,CO2)
    legend('CO2')
    datetick('x','dd-mmm-yyyy HH:MM:SS','keeplimits','keepticks')
    figure()
    plot(x,H2O)
    legend('H2O')
    datetick('x','dd-mmm-yyyy HH:MM:SS','keeplimits','keepticks')
    figure()
    plot(x,FC)
    legend('FC')
    datetick('x','dd-mmm-yyyy HH:MM:SS','keeplimits','keepticks')
    figure()
    hold on
    plot(x,LE)
    plot(x,H)
    legend('LE','H')
    datetick('x','dd-mmm-yyyy HH:MM:SS','keeplimits','keepticks')
    hold off
    figure()
    hold on
    plot(x,G)
    plot(x,SG)
    legend('G','SG')
    hold off
    figure()
    plot(x,WS)
    legend('WS')
    datetick('x','dd-mmm-yyyy HH:MM:SS','keeplimits','keepticks')
    figure()
    plot(x,ZL)
    legend('ZL')
    datetick('x','dd-mmm-yyyy HH:MM:SS','keeplimits','keepticks')
    figure()
    hold on
    plot(x,TA1)
    plot(x,TA2)
    legend('TA1','TA2')
    datetick('x','dd-mmm-yyyy HH:MM:SS','keeplimits','keepticks')
    hold off
    figure()
    hold on
    plot(x,RH1)
    plot(x,RH2)
    legend('RH1','RH2')
    datetick('x','dd-mmm-yyyy HH:MM:SS','keeplimits','keepticks')
    hold off
    figure()
    plot(x,VPD)
    legend('VPD')
    datetick('x','dd-mmm-yyyy HH:MM:SS','keeplimits','keepticks')
    figure()
    plot(x,ALB)
    legend('ALB')
    datetick('x','dd-mmm-yyyy HH:MM:SS','keeplimits','keepticks')
    figure()
    hold on
    plot(x,SWin)
    plot(x,SWout)
    plot(x,LWin)
    plot(x,LWout)
    legend('SWin','SWout','LWin','LWout')
    datetick('x','dd-mmm-yyyy HH:MM:SS','keeplimits','keepticks')
    hold off
    i=i+1;
end

Best Answer

"I want to change it so that a different file is opened with each loop but i'm not sure how"
By following the guidelines in the MATLAB documentation:
https://www.mathworks.com/help/matlab/import_export/process-a-sequence-of-files.html
So you could either use dir to read the names from a folder, or generate the names using sprintf. Pick whichever works best for you. Here is an example with sprintf:
opt = {'Delimiter',',', 'Headerlines',1};
fmt = ['%s',repmat('%f',1,13),'%s%s',repmat('%f',1,29),'%s%s',repmat('%f',1,8)];
for k = 1:41
    fnm = sprintf('7633_Flux_AmeriFluxFormat_%d.dat',k); % I had to guess the name format
    [fid,msg] = fopen(fnm,'rt');
    assert(fid>=3,msg) 
    A = textscan(fid,fmt,opt{:});
    x = datenum(A{1,1},'yyyymmddHHMM'); % simpler
    ...
end
Note that you did not give any information on how the files names change, so I just guessed that the numbered suffix increments each time: if the names have some other pattern, you will have to specify that yourself, or give us a precise specification, or use dir.
Calling fopen directly inside textscan is an inspired move, but is not recommended: MATLAB does not automatically close those files, so you will end up with a large number of open files, which is not a good idea (it can even crash MATLAB if there are too many). So you should always use fclose if you fopen any file.
Note that your code could be significantly simplified by using readtable.
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