merge and displace the data and save into txt file

Hi all,

I have a file full of ascii data with 6 columns (col1 is day, col2 is month, col3 is year and col4 to col6 are data). I would like to create the txt.file as below format by using matlab. Each column was separated by tab. (please see attached file for data)

ABCDEFGH
Date name1 name2 name3
19800101  0.5249 11.1333 1.0302
19800102  0.0460 10.8523 1.0302
19800103  0.0692 12.0476 1.0302
...
20071231  0.0649 13.4099 1.0491

Could someone please help and code this in Matlab? Thanks so much.

NAM

Answer 1

[Geoff Hayes]

Nam - try importing the data into a matrix using importdata as

 inputData=importdata('data.txt');

You can then build the output matrix as

 outputData = [ inputData(:,3)*10000+inputData(:,2)*100+inputData(:,1) inputData(:,4:6)];

The above just "builds" the first column of outputData by summing the year, month, and day columns from inputData, and then concatenates that result with the final three columns.

To save this to file, just do something like

 dlmwrite('myOutput.txt',outputData,'precision','%d','delimiter','\t');

You can adjust the precision as you see fit. The above will write the following to your text file

 ...
 20071229  3.113964e-02  1.274519e+01  1.049144e+00
 20071230  6.487198e-02  1.340989e+01  1.049144e+00
 20071231  6.487198e-02  1.340989e+01  1.049144e+00

[Geoff Hayes]

Nam's answer moved here

Thanks Geoff Hayer for your helping.

There are very useful scripts. But I have 2 questions such as:

1. I did as you suggest about adjustment the precision by use the script:

   dlmwrite('myoutput.txt',outputData,'precision',5, 'delimiter','\t');

It should be adjusted all the value. How do I only adjust last 3 values?

2. How do I add the 2 text lines above these data into text file?

 THIS IS DATA FOR ANALYSIS

 Date value1[kg/m3/s] value2[kg/m3/s] value3[kg/m3/s]

Thanks

NAM

[Geoff Hayes]

Nam - if you want to add the additional text and set the formatting for each column, then you will have to use fopen and fprintf to write the data to file. Try the following

 % open the file for writing
 fid = fopen('myoutput.txt','wt');
 if fid>0
     fprintf(fid,'THIS IS DATA FOR ANALYSIS\n');
     fprintf(fid,'Date\tvalue1[kg/m3/s]\tvalue2[kg/m3/s]\tvalue3[kg/m3/s]\n');

     fprintf(fid,'%d\t%.5f\t%.5f\t%.5f\n',outputData');

     % close the file
     fclose(fid);
 end

Answer 2

[Nam]

Thanks Geoff Hayer for your helping.

There are very useful scripts. But I have 2 questions such as:

1. I did as you suggest about adjustment the precision by use the script:

    dlmwrite('myoutput.txt',outputData,'precision',5, 'delimiter','\t');

It should be adjusted all the value. How do I only adjust last 3 values?

2. How do I add the 2 text lines above these data into text file?

THIS IS DATA FOR ANALYSIS

Date value1[kg/m3/s] value2[kg/m3/s] value3[kg/m3/s]

Thanks

NAM