convert csv file and write to another .m file
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Arif Ahmed
on 5 Jul 2020
Commented: Walter Roberson
on 7 Jul 2020
Hello,
I am having problem reading in this file to matlab.
Data = readtable('100Cr6.csv','NumHeaderlines',0,'DecimalSeparator',',');
FID = fopen('kf100CR6.m', 'w');
fwrite(FID, Data, 'char');
fclose(FID);
i use the following code but it does not run successfully?
every time showing an error message:
"Error using fwrite
Cannot write value: unsupported class table
Error in convertCSV (line 15)
fwrite(FID, Data, 'char');"
i want every data in double notation (like 1231.2354) format in a .m file. so that i can use these as columns or rows of matrix.
Does anyone have a solution to this?
Many thanks.
2 Comments
Walter Roberson
on 6 Jul 2020
you have columns that have three parts separated by semi-colon. If those are acting as decimal points then you have too many of them. If they are acting as group separation then you appear to be missing a decimal separation.
jonas
on 6 Jul 2020
Accepted Answer
Walter Roberson
on 6 Jul 2020
filename = '100Cr6.csv';
S = fileread(filename);
S = regexprep(S, {',', ';'}, {'.', ','});
mdata = cell2mat( textscan(S, '', 'HeaderLines', 1) );
4 Comments
Walter Roberson
on 7 Jul 2020
No, it should not be. Your input data has 0,1 for the first column, but you take log() of that to create the new first column. The result is not going to be 0,1 .
Look at
exp(mdata(1:10,1))
after my suggested code, and you will see
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
If this is not acceptable, then you need to tell us how you want the input "0,1" to be interpreted. Is it a pair of numbers 0 and 1, and you want log() of the first column to be log of 0 giving you -infinity, and log of the second part (1) to give you 0 ? Is it to be interpreted as 0 times 1 plus 1 times 1/10 with the comma acting as the decimal separator ? Are we intended to somehow understand the input "0,1" as indicating a number such that the result of the log() you do gives 0.1 -- that is, is the comma in "0,1" intended to indicate that the input number is to be intepreted as exp(0.1) ?
Or is the issue that output lines such as mdata(1,:)
-2.30258509299405 -3.2188758248682 0.04 20 6.12844000213506
use decimal points, and that you need the output to instead be
-2,30258509299405 -3,2188758248682 0,04 20 6,12844000213506
?
More Answers (2)
jonas
on 6 Jul 2020
Error message says that table class is not supported. You can pass the content of the table or just read the data as a matrix directly. I would try
Data = readmatrix('100Cr6.csv','NumHeaderlines',1,'DecimalSeparator',',')
dlmwrite('filename.m', Data)
5 Comments
jonas
on 6 Jul 2020
I am getting the expected output.
Data = readmatrix('100Cr6.csv','NumHeaderlines',1,'DecimalSeparator',',')
dlmwrite('kf100CR6.m', Data)
clear all
mdata = load('kf100CR6.m');
size(mdata)
ans =
1248 4
mdata = [log(mdata(:,1)) log(mdata(:,2)) mdata(:,2) mdata(:,3) log(mdata(:,4))];
size(mdata)
ans =
1248 5
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