Transferring datasheet curves to Excel?

Discussion in 'General Electronics Chat' started by umphrey, Jun 16, 2014.

  1. umphrey

    Thread Starter Member

    Dec 1, 2012
    I end up doing this a lot where I have a datasheet with a curve and I want to transfer the data points over to Excel. Does anyone know a program that does this more efficiently than manually reading the datapoints? Something graphical perhaps?

    See attached,
  2. shteii01

    AAC Fanatic!

    Feb 19, 2010
    It is called spreadsheet because it is all about numbers. Pretty pictures are an extra.
  3. tshuck

    Well-Known Member

    Oct 18, 2012
    I've seen something that allows one to import a screenshot of a graph, select axis ranges & units, and trace over the graph so as to replicate the data captured by the graph and interpolate along the trace.

    I'm not sure if something exists in the wild, though...

    Edit: It seems there is a number of software that can do this.

    Blueleaf software make something that seems to do this.

    plotdigitizer may also be up for the task...
    Last edited: Jun 16, 2014
  4. wayneh


    Sep 9, 2010
    I've digitized charts a number of ways. Quick and dirty brute force is to use the copy machine to blow it up, and then pick points manually. It's easier to choose points where the curve crosses over a grid line. If you don't have gridlines, I've used a ruler to draw my own.

    Or you can import a scan or screen capture of a graph into Excel, and then create a transparent Excel chart on top of it. You makes the axes to line up nicely and sometimes you can fit the curve with an equation.

    I never had the benefit of an automated digitizer. Sounds like a great tool if it works.
  5. KMoffett

    AAC Fanatic!

    Dec 19, 2007
    Going to be tough to get accurate numbers off of a log-log graph like that.

  6. Gdrumm

    Distinguished Member

    Aug 29, 2008
  7. wayneh


    Sep 9, 2010
    There an expression we always used in the lab: "Anything is a straight line on a log-log plot." Not exactly true, but the point is you can often make rough data look like good, smooth data by using a log-log plot.