Find the answer to your Linux question:
Results 1 to 3 of 3
I don't know if this is the correct place for this, but I wanted to graph in gnuplot one column of a data file using the formula y=mx+b... where m ...
Enjoy an ad free experience by logging in. Not a member yet? Register.
  1. #1
    LRG
    LRG is offline
    Just Joined!
    Join Date
    Jun 2009
    Location
    New York
    Posts
    12

    plotting a data file in ginuplot in linux


    I don't know if this is the correct place for this, but I wanted to graph in gnuplot one column of a data file using the formula y=mx+b... where m is a constant and b is a constant...x is the data and y is unknown. I known how to move that one column of data to its own file and that's what I have done. I need a code for the mx+b graph though...I obviously know how to apply that formula but I don't know how to make gnuplot do it for a very large number of data point (x). Please help

    Because I did not know how to make a line like that with many x values in gnuplot, I just found 2 points by solving for two specifc x's...this did work but once I graphed the line I could not figure out how to extend the line further than those two points...

    ~So if it is possible to extend the line of thosetwo points then what is the code? ... would doing a best fit line for those two points give me the line for all of those data points? If so...how do I do that?
    ~If not, then what is the code to just graph all of those data points for x?

    Any suggestions are appreciated.

    Thanks

  2. #2
    Linux Guru Cabhan's Avatar
    Join Date
    Jan 2005
    Location
    Seattle, WA, USA
    Posts
    3,252
    So you basically have a column of data (which we will call x) and you want to plot coordinates by using that x and a y which is a formula?

    I suspect this will work:
    Code:
    plot "datafile.dat" using 1:(m * $1 + b)
    You will obviously need to fill in m and b.

    This works by telling plot which columns to use. Here we say that the first column will be used for the x value, and the expression that we have given will be used for the y value. In that expression, $1 refers to the first column of the datafile.

    I hope this helps! You can learn more at:
    Using

  3. #3
    LRG
    LRG is offline
    Just Joined!
    Join Date
    Jun 2009
    Location
    New York
    Posts
    12
    Thankyou SO much, it did work, I've been trying to figure it out forever..

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •