Re: Digitizing plots with Mathematica (i.e. extracting data points
- To: mathgroup at smc.vnet.net
- Subject: [mg107685] Re: Digitizing plots with Mathematica (i.e. extracting data points
- From: "Kevin J. McCann" <Kevin.McCann at umbc.edu>
- Date: Mon, 22 Feb 2010 19:05:25 -0500 (EST)
- References: <hlte0v$s7c$1@smc.vnet.net>
You should probably also consider the possibility that your image is not
exactly horizontal/vertical. This will likely be the case if you scan an
image from a book or journal.
Kcvin
Will DeBeest wrote:
> I've just written a blog post showing how to make a plot digitizer
> using Mathematica. It may be of interest to other Mathematica users
> particularly anyone who wants to extract some data out of plots.
>
> barChartDigitizer[g_Image] :=
> DynamicModule[{min = {0, 0}, max = {0, 0}, xmin = -1., xmax = 1.,
> pt = {0, 0}, data = {}, img = ImageDimensions[g], output},
>
> Deploy@Column[{
> Row[{
> Column[{Button["Y Axis Min", min = pt],
> InputField[Dynamic[xmin], Number, ImageSize -> 70]}],
> Column[{Button["Y Axis Max", max = pt],
> InputField[Dynamic[xmax], Number, ImageSize -> 70]}],
> Column[{Button["Add point", AppendTo[data, pt]],
> Button["Remove Last", data = Quiet@Check[Most@data, {}]]}],
> Column[{Button["Start Over", data = {}],
> Button["Print Output",
> Print@Column[{BarChart[
> output =
> Rescale[#, {Last@min, Last@max}, {xmin, xmax}] & /@
> data[[All, 2]],
> PlotRange -> {Automatic, {xmin, xmax}},
> ImageSize -> 400], output}],
> Enabled -> Dynamic[data =!= {}]]}]
> }],
> Row[{
> Graphics[{Inset[
> Image[g, ImageSize -> img]], {Tooltip[Locator[Dynamic[pt]],
> Dynamic[pt]]}},
> ImageSize -> img, PlotRange -> 1,
> AspectRatio -> img[[2]]/img[[1]]]}]
> }]
> ]
>
> A full description will a worked example can be found here:
>
> http://www.wildebeests.net/2010/02/21/digitizing-plots-with-mathematica/
>