[pilx] Exception when running the diffmap

[kif]

ERROR:silx.gui.plot.tools.PositionInfo:Error while converting coordinates (81.000000, 57.000000)with converter 'Data'
ERROR:silx.gui.plot.tools.PositionInfo:Traceback (most recent call last):
  File "/users/kieffer/.venv/py312/lib/python3.12/site-packages/silx/gui/plot/tools/PositionInfo.py", line 299, in _updateStatusBar
    value = func(xData, yData)
            ^^^^^^^^^^^^^^^^^^
  File "/users/kieffer/.venv/py312/lib/python3.12/site-packages/pyFAI/gui/pilx/widgets/MapPlotWidget.py", line 94, in _dataConverter
    index = self.getScatterIndex(x, y)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/users/kieffer/.venv/py312/lib/python3.12/site-packages/pyFAI/gui/pilx/widgets/MapPlotWidget.py", line 168, in getScatterIndex
    pixel_x, pixel_y = self.dataToPixel(x_data, y_data)
    ^^^^^^^^^^^^^^^^
TypeError: cannot unpack non-iterable NoneType object

Should at least be silenced out.

[loichuder]

How to reproduce this ?

[kif]

This is when moving the mouse around.

[EdgarGF93]

It happens sometimes when the mouse is right at the edge of the map widget. Due to numeric precision, sometimes the position of the cursor goes out of the edges.

I put these debugging lines at datatoPixel method

        if check:
            isOutside = numpy.logical_or(
                numpy.logical_or(x > xmax, x < xmin),
                numpy.logical_or(y > ymax, y < ymin),
            )
            print(f"{isOutside=}")
            print(f"{x=}, {y=}")
            print(f"{xmin=}, {xmax=}")
            print(f"{ymin=}, {ymax=}")

isOutside=False
x=-0.41312354735751144, y=1.201234995383195
xmin=-0.42311233885819544, xmax=0.7227849396357682
ymin=1.128654970760234, ymax=1.6915204678362574
isOutside=False
x=-0.41593729144221114, y=1.201234995383195
xmin=-0.42311233885819544, xmax=0.7227849396357682
ymin=1.128654970760234, ymax=1.6915204678362574
isOutside=False
x=-0.41875103552691084, y=1.201234995383195
xmin=-0.42311233885819544, xmax=0.7227849396357682
ymin=1.128654970760234, ymax=1.6915204678362574
isOutside=False
x=-0.4215647796116106, y=1.201234995383195
xmin=-0.42311233885819544, xmax=0.7227849396357682
ymin=1.128654970760234, ymax=1.6915204678362574
isOutside=True
x=-0.42437852369631035, y=1.2061724120242125
xmin=-0.42311233885819544, xmax=0.7227849396357682
ymin=1.128654970760234, ymax=1.6915204678362574
ERROR:silx.gui.plot.tools.PositionInfo:Error while converting coordinates (81.000000, 227.000000)with converter 'Data'
ERROR:silx.gui.plot.tools.PositionInfo:Traceback (most recent call last):
  File "/users/edgar1993a/anaconda3/envs/ewoks/lib/python3.9/site-packages/silx/gui/plot/tools/PositionInfo.py", line 299, in _updateStatusBar
    value = func(xData, yData)
  File "/home/edgar1993a/work/pyFAI/build/lib/python3.9/site-packages/pyFAI/gui/pilx/widgets/MapPlotWidget.py", line 104, in _dataConverter
    index = self.getScatterIndex(x, y)
  File "/home/edgar1993a/work/pyFAI/build/lib/python3.9/site-packages/pyFAI/gui/pilx/widgets/MapPlotWidget.py", line 181, in getScatterIndex
    pixel_x, pixel_y = self.dataToPixel(x_data, y_data)
TypeError: cannot unpack non-iterable NoneType object

In the last interaction, the mouse x is at -0.42437852369631035 while the minus limit is at -0.42311233885819544

[EdgarGF93]

fixed in #2235

[EdgarGF93]

It happens only when the cursor is moving around the left and top axis (x-minimum and y-maximum). In this patch, I catch the error and continue.