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.
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).
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[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( int iplot, int x, int y ) → QDataSet