|
[Sponsors] |
Matlab:extract 10000 first lines from a file and write them in a new file |
|
LinkBack | Thread Tools | Search this Thread | Display Modes |
September 5, 2012, 22:20 |
Matlab:extract 10000 first lines from a file and write them in a new file
|
#1 |
New Member
ron leco
Join Date: Sep 2012
Posts: 3
Rep Power: 13 |
Hello,
I have a file "myfile.txt" containing 45000 lines (it is not a matrix). I would like to read the 10000 first lines of my file ( the 10000 first lines define a matrix 3 columns ) and write it in a new txt file name "b.txt". How can I do that ? Please find below the bits of program I have already. Thank you in advance. Ronald fid=fopen(' myfile.txt,'r'); N = 10000 for n = 1:N fgetl(fid); end fprintf(fid,'%d %d %d\n','b'); fclose(fid); |
|
September 6, 2012, 04:53 |
|
#2 |
Senior Member
Gerhard Holzinger
Join Date: Feb 2012
Location: Austria
Posts: 335
Rep Power: 28 |
I did no testing, but shouldn't it look rather like this:
fidRead = fopen('myfile.txt'); fidWrite = fopen('b.txt'); for i=1:N line = fgetl(fidRead); writeLine(fidWrite); end fclose(fidRead); fclose(fidWrite); The code above is some mix of pseudo-code and actual code, but in principle I would do it like this. Open both files; read a line and write it right away, repeat this until you are done Close both files |
|
September 6, 2012, 20:25 |
writeLine(fidWrite)
|
#3 |
New Member
ron leco
Join Date: Sep 2012
Posts: 3
Rep Power: 13 |
I wrote the program attached below and created a file b.txt with nothing in it in order to fill it with the help of the program ; it gives me the following error message :
"??? Attempted to access writeline(19); index out of bounds because numel(writeLine)=1 Error in ==>prog3 at 12 writeLine(fidWrite)" Why do I have this error ? Is it correct to create a file b.txt before launching the program. How can I declare b as a matrix 10000 X 3 in the program ? Thank you. Ron fidRead = fopen('myfile.txt','r'); fidWrite = fopen('b.txt','w'); N=10000 for i=1:N line = fgetl(fidRead); writeLine(fidWrite); end fclose(fidRead); fclose(fidWrite); |
|
September 7, 2012, 03:33 |
|
#4 |
Senior Member
Bernhard
Join Date: Sep 2009
Location: Delft
Posts: 790
Rep Power: 21 |
Supposing you are using Linux, you can easily do this. It seems a bit useless to do it with Matlab.
Code:
$ head a.txt -n 10000 > b.txt |
|
September 7, 2012, 03:34 |
|
#5 |
Senior Member
Gerhard Holzinger
Join Date: Feb 2012
Location: Austria
Posts: 335
Rep Power: 28 |
as I wrote in my posting, my code contains some pseudocode. There is no function in Matlab called writeLine. Check the matlab help to see how to read and write from files, especially what those function expect as argument.
Depending on how you call fopen() b.txt will be created, will be overwritten or any things you write will be appended if this file exists. |
|
September 24, 2013, 12:23 |
Scilab-colorbar
|
#6 |
New Member
ron leco
Join Date: Sep 2012
Posts: 3
Rep Power: 13 |
Hello,
I would like to plot 2 graphs with 1 colorbar. The colour bar wouldn't not vary but the graph would vary with respect to the colorbar. For instance the values vary from 0 to 1600 for the 1st plot, from 0 to 1200 in the second plot. The colorbar would vary from 0 to 1600, but the 2nd plot would have the colours corresponding to the maximum values being 1200 in the colorbar thus clearer than he maximum of the colorbar. Please find attached below my program in scilab. At the moment I am able to plot each graph but with a new colorbar each time varying from the min to the max of the values of the plot. If I put 1600 for the max of the colorbar, the corresponding colour (1600) is also displayed on the graph even if the max on the graph is 1200. Thank you for your help. aa1=gca();aa1.x_location="bottom"aa1.y_location="right"xset("colormap",jetcolormap(64))aa=min(y3)b=max(y3)colorbar(aa,b)Sgrayplot(x,y,y3)xtitle(" T distribution","x (meter)","y (meter)") |
|
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
mesh file for flow over a circular cylinder | Ardalan | Main CFD Forum | 7 | December 15, 2020 14:06 |
[Helyx OS] Helyx-OS (GUI for SnappyHexMesh | elvis | OpenFOAM Community Contributions | 210 | January 30, 2017 19:57 |
openfoam 1.6 on debian etch | romant | OpenFOAM Installation | 9 | May 6, 2010 03:26 |
Write .def file from command line | Alejandro | CFX | 3 | September 11, 2005 19:14 |
Results saving in CFD | hawk | Main CFD Forum | 16 | July 21, 2005 21:51 |