LiveGraph displaying erronius data in graph?

2012-03-12
2013-05-28
  • audiobahn1000
    audiobahn1000
    2012-03-12

    I have a .csv file that gets updated 100 times a second. It captures very fast peak transits from a load cell. Anyway, LiveGraph is not displaying the peaks appropriately, its just averaging the values and piloting that. I need to see the peak values, I dont care about the average. How can I get the program to chart out the exact numbers from the .csv datasets, and not averages?

     
  • Greg Paperin
    Greg Paperin
    2012-03-12

    LiveGraph dies not average the data, but it does interpolate between data points. Remember that if your plot Window is only X pixels wide, you cannot possibly see more than X points at a time, so once your data file has more than a certain number of points, LiveGraph will begin leaving some data points out.
    You can select "Show tail data" in the Data File Settings window. Then LiveGraph will never skip data points. If your data grows too large, it will only show the most recent data points.

     
  • audiobahn1000
    audiobahn1000
    2012-03-14

    Well what is the best way to view a very large dataset? My dataset contains hundreds of thousands of values, but more than 99% of the value sets are useless data to me, mostly zeros. How can I view the entire dataset but than zoom or scroll into a specific region?

     
  • min_hero
    min_hero
    2012-03-14

    I wish to reply instead of the developper and correct me if i am wrong.
    I ve used vere large datasets.
    To display the whole datasetsof N datapoints, you need the same amount of pixels, either in X or Y axis depending on your display of N points.
    So you cannot display more points than your screen analysis.
    There are solutions to that, one is to interpolate like the developper does, whenever the dataset exceeds the plotting canvas, though i can say the interpolation he does is missing half the points in every iteration of the points, which is though statistically correct in large data points!.
    Another is, like i have studied, to choose to display extrema per region of points. So you can choose the biggest in absolute value to display.

    In any case, the way to display your dataset, depends on your dataset's statistical values.