Re: interactive dragrect over a raster image

*To*: mathgroup at smc.vnet.net*Subject*: [mg89629] Re: interactive dragrect over a raster image*From*: "David Park" <djmpark at comcast.net>*Date*: Sun, 15 Jun 2008 06:14:59 -0400 (EDT)*References*: <g3038u$mei$1@smc.vnet.net>

Here is one solution. I make the width and height of the rectangle dynamically adjustable. The red point is a locator to position the rectangle. You could add another plot in a row to give a histogram analysis, but since I don't know what that might be I simply output the number of points in the rectangle. data = RandomReal[{0, 10}, {100, 2}]; DynamicModule[ {pt = {0, 0}, width = 2., height = 1.}, Column[{ Item[Style["Analysis With Data Sampler", "Panel", Large, Background -> None], Alignment -> Center], Row[{"width: ", InputField[Dynamic[width], ImageSize -> {60, 20}], Spacer[10], "height: ", InputField[Dynamic[height], ImageSize -> {60, 20}], Spacer[10], "center: ", Dynamic@NumberForm[pt + {width, height}/2, {4, 2}]}], Row[{"Point count in sample: ", Dynamic@Length@ Select[data, First[pt] <= First[#] <= First[pt] + width \[And] Last[pt] <= Last[#] <= Last[pt] + height &]}], Graphics[ {Yellow, Dynamic@Rectangle[pt, pt + {width, height}], Black, AbsolutePointSize[3], Point /@ data, Locator[Dynamic[pt], Graphics[{Red, AbsolutePointSize[6], Point[{0, 0}]}]]}, Frame -> True, PlotRange -> {{0, 10}, {0, 10}}, PlotRangePadding -> 1, ImageSize -> 400](* Graphics *) }](* Column *) ] -- David Park djmpark at comcast.net http://home.comcast.net/~djmpark/ "rych" <rychphd at gmail.com> wrote in message news:g3038u$mei$1 at smc.vnet.net... >I would like to be able to drag a rectangle with mouse over a raster > image plot and dynamically update another plot, a histogram, for > example, for the corresponding region? Something like Slider2D on the > background of the image? Or is it better to program it using NETLink, > or something? > Igor >