Plotting data from text file

Question

Cagas Akalin 2016-10-13

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/307079-plotting-data-from-text-file

评论： Cagas Akalin 2016-10-13

Dear All,

The problem that I am dealing with is to obtain a plot from a text file has 5615917 lines of data. The shorthaned content of the data file that I am dealing with looks like as follows.

channel names:
09/07/2016 06:20:09 PM - Thermocouple - SC1Mod2_ai2
start times:
9/7/2016 18:20:13.504689
dt:
010000
data:
857533E+1
857165E+1
856430E+1
857165E+1
856798E+1
857165E+1
856798E+1
857900E+1
856430E+1
857165E+1
857165E+1
856798E+1
856430E+1
856798E+1
.
.
.
635587E+1
635209E+1
635965E+1
635587E+1
635209E+1
635965E+1
635965E+1
635209E+1
635587E+1
635965E+1
634832E+1

and the code that I use is

             clear all
             close all
             clc
    fileID = fopen('ThermocoupleCombined.txt','r');
Crude_Data = textscan(fileID,'%f','HeaderLines','2');
             fclose(fileID);
         C = transpose(0:0.01:0.01*(length(Crude_Data{1})-1));
             plot(C,Crude_Data{1})

The code above draws the data up to 76757 and the rest is not included inside "Crude_Data" and not plotted.

Can you please give me your suggestions regarding the problem I have?

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Cagas Akalin 2016-10-13

class of B is cell while class of C is double. Also you can find the file in the link below.

https://www.dropbox.com/s/08mpjcc542cx0de/ThermocoupleCombined.txt?dl=0

KSSV 2016-10-13

That's why error popped out. What are respective sizes? Mean while I will check your data.

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Answer 1

KSSV 2016-10-13

2
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/307079-plotting-data-from-text-file#answer_238781

Dear friend

Check the line 76807..there is change in the format.....So MATLAB is plotting fine from line 8 to 76807. You have to change the pattern of reading the file using textscan().

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KSSV 2016-10-13

在 MATLAB Online 中打开

fileID = fopen('ThermocoupleCombined.txt','r');
% Crude_Data = textscan(fileID,'%f','HeaderLines','2');
% Crude_Data = textscan(fileID,'%f','HeaderLines',7);
Crude_Data = textscan(fileID,'%s','delimiter','\n');
C = Crude_Data{1} ;
fclose(fileID);
IdxC = strfind(C, 'data');
Idx = find(not(cellfun('isempty', IdxC)));
% split the data
data1 = C(Idx(1)+1:Idx(2)-9) ;
data1 = data1(~cellfun('isempty',data1)) ; % remove empty cells if any   
data2 = C(Idx(2)+1:end) ;
% convert to double 
data1 = sprintf('%s*', data1{:});
data1 = sscanf(data1, '%f*');
t1 = 0:0.01:0.01*(length(data1)-1);
data2 = sprintf('%s*', data2{:});
data2 = sscanf(data2, '%f*');
t2 = 0:0.01:0.01*(length(data2)-1);
plot(t1,data1,'r') ;
hold on
plot(t2,data2,'b') ;

Cagas Akalin 2016-10-13

Dear Kolukula,

Thanks for your help and suggestions. Actually, the .txt file read by Matlab is the combination of two with their individual headers. I copied one and pasted it end of the other however, fortunately I forgot deleting the header part of subsequent data. After your warning, recreating merged file without header part in between allowed the code plot the figure without any error.

Thank you very much again for your time.

Best wishes.

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