in reply to Re: Graph a file without using arrays
in thread Graph a file without using arrays

In response to Grandfather and BrowserUK…

I have files that contain ping travel times between nodes. I want to be able to graph this data using scatter graphs. (I would also like to create histograms with logarithmic scales. I have not found out how to do this in perl, so any advice you can give would be appreciated) The files contain over 8600 lines of data. Each line contains a timestamp and the time too and from the test site. I am not concerned about being able to see each single point. Most of the data will be grouped together and will form a line. This is just to be able to see a visual distribution of travel time in relation to time of day.
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Re^3: Graph a file without using arrays
by BrowserUk (Patriarch) on Sep 22, 2008 at 20:33 UTC
    The files contain over 8600 lines of data.

    8640 data points (I'm assuming that you are pinging once every 10 seconds over each 24 hr period?), is not a lot of data. There really is no need to do you own thing. I just generated a 8640 timestamps/random times and plotted them on a 1024x768 points graph, and the total memory usage was well under 10 MB for the program, data and graph.


    Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
    "Science is about questioning the status quo. Questioning authority".
    In the absence of evidence, opinion is indistinguishable from prejudice.
      Thanks, but when I originally ran my program the system slowed down and became sluggish. That is why I was trying to graph the file directly and not from an array. Do you know if this is possible? If not, then I'll just stick to using an array. Who knows, maybe its just the computer....
        when I originally ran my program the system slowed down and became sluggish.

        Then I think you are attributing the slowdown to the wrong cause. Perhaps if you posted the code, we could suggest an alternative reason for it.

        That is why I was trying to graph the file directly and not from an array. Do you know if this is possible?

        It is certainly possible. GD::Graph just does some math on the arrays and then calls the graphic primitives in GD to do the drawing. You could do this yourself, perhaps picking apart GD::Graph as your starting point. It would require two passes of the data.

        But, as I pointed out above, 8640 data points is a trivial amount of data, and cannot be the reason for the "slow down and sluggishness", so it's unlikely that just making this change would achieve the result you are looking for. One has to suspect that there is some other aspect of your code that is responsible for the problem you are seeking to fix. And if you fixed that problem, there would be no need to role your own graphing solution to avoid the use of arrays.

        Who knows, maybe its just the computer....

        Computers are amazingly consistant. It is much more likely to be your unshown code...


        Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
        "Science is about questioning the status quo. Questioning authority".
        In the absence of evidence, opinion is indistinguishable from prejudice.