## org.autoplot.pngwalk.ClickDigitizer

Quick-n-dirty class for picking off points from images. The ClickDigitizer knows how to grab JSON metadata from the image (http://autoplot.org/richPng) and invTransform the pixel location to a dataset.

## ClickDigitizer( org.autoplot.pngwalk.PngWalkView view )

## dataToPixelTransform

dataToPixelTransform( int iplot, QDataSet p ) → int[]

return the pixel coordinates for a given data coordinates.

### Parameters

iplot - the plot number
p - bundle of x and y data coordinates.

### Returns:

int[2] for the x and y pixel coordinates (0,0 is upper left).
[search for examples] [view on GitHub] [view on old javadoc]

## pixelToDataTransform

pixelToDataTransform( int x, int y ) → QDataSet

return the coordinates for the click in data coordinates if the JSON Rich PNG metadata is available, or just the pixel coordinates if it is not, with the property "PlotNumber" indicating which plot number in the JSON is used. The property "PlotNumber" will be an integer equal -1 if the rich png metadata is not found, or zero or positive int for valid clicks. If the x and y are not within a plot, then -1 is returned for the plot number.

### Parameters

x - the horizontal pixel coordinate
y - the vertical pixel coordinate, with 0 at the top.

### Returns:

two-element bundle QDataSet with PlotNumber property. -1 indicates no plot found at the location, and -99 means no rich png data.
[search for examples] [view on GitHub] [view on old javadoc]

## pixelToDataTransform

pixelToDataTransform( int iplot, int x, int y ) → QDataSet

return the coordinates for the click in data coordinates if the JSON Rich PNG metadata is available, or just the pixel coordinates if it is not, with the property "PlotNumber" indicating which plot number in the JSON is used. The property "PlotNumber" will be an integer equal -1 if the rich png metadata is not found, or zero or positive int for valid clicks. If the x and y are not within a plot, then null (None) is returned.

### Parameters

iplot - the plot number, or -1 to indicate whichever plot x and y are within.
x - the horizontal position
y - the vertical position, with 0 being the top of the plot.

### Returns:

two-element bundle QDataSet with PlotNumber property. -1 indicates no plot found at the location, and -99 means no rich png data.
[search for examples] [view on GitHub] [view on old javadoc]