Plotting data from text file

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:
0.010000
data:
8.857533E+1
8.857165E+1
8.856430E+1
8.857165E+1
8.856798E+1
8.857165E+1
8.856798E+1
8.857900E+1
8.856430E+1
8.857165E+1
8.857165E+1
8.856798E+1
8.856430E+1
8.856798E+1
.
.
.
2.635587E+1
2.635209E+1
2.635965E+1
2.635587E+1
2.635209E+1
2.635965E+1
2.635965E+1
2.635209E+1
2.635587E+1
2.635965E+1
2.634832E+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?

[Adam]

Does the format change at line 76757?

[KSSV]

Are you sure that after the word 'data' all are numbers and no text exits? Go to the line 76757 and see what is the data there.

[Cagas Akalin]

I checked the line 76757 but there is no format change where Matlab stops reading.

The screen shot of row data is below.

[KSSV]

What is length of Crude_Data?

Try with importdata....

data = imortdata('yourfile') ;

then data will be a structure with your matrix of numbers and text. Take matrix from the data (data.data) and see it's size.

[Cagas Akalin]

Dear Kolukula,

Upon your advise what I tried is to implement "importdata" function in my code. The new coding idea implies that

            clear all
            close all
            clc

        A = importdata('ThermocoupleCombined.txt');
        B = A.textdata(8:length(A.textdata),1);
        C = transpose(0:0.01:0.01*(length(B)-1));

            plot(C,B)

However, Matlab gives the error below.

---------------------------------------------------
Error using plot
Conversion to double from cell is not possible.

Error in CFRPCuringTempAnalysisII (line 9)
            plot(C,B)
---------------------------------------------------

Actually, this is what I tried before but I could not get rid of this error.

[KSSV]

That case there is a problem in plot. check class(B) and class(C)..tell me there classes. If possible try to attach the txt file here.

[Cagas Akalin]

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]

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

Answer 1

[KSSV]

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().

[KSSV]

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]

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.