| IDLgrPlot and Widget event [message #54140] |
Fri, 25 May 2007 08:16  |
Laurens
Messages: 41
Registered: May 2006
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Member |
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Hi All,
After much irritation from not being able to write a universal class for
drawing every kind of curve, (as usual) David's suggestion to me a few
months ago did the trick;
All measures are normalized to 0->1 so Axis, Curve/Plot and Symbols, all
are scaled to that 0-> scale; the curve draws fine.
Now, I am catching the MOTION event from the mouse cursor; I want to
have something like a crosshair to accentuate the position of the mouse
cursor (see link for example img).
Catching the event and drawing the polylines almost goed well, except
for the fact that I don't seem to be able to position the lines at the
right place. I guess this has to do since the event.x delivers me the
pixel-position on the widget, say 98. But 98 is a bit tough to fit onto
a scale of 0->1.
So the actual question: how do I get from an event.x or event.y to a
position in my normalized plot?
Code I now have:
============================================================ ==
*xAxis->GetProperty, CRange=xrange
*yAxis->GetProperty, CRange=yrange
self.View->GetProperty, VIEWPLANE_RECT = viewplane
position = [0.20, 0.15, 0.925, 0.925]
xs = Normalize(xrange, Position=[position[0], position[2]])
ys = Normalize(yrange, Position=[position[1], position[3]])
; Scale the plot data and axes into 0->1.
*(xLine)->SetProperty, XCoord_Conv=xs
*(yLine)->SetProperty, YCoord_Conv=ys
fraction = 1 ; ??? <-- how to get something useful here...
scaledX = mean( event.x )
scaledY = mean( fraction * event.y )
; Plot lines
*(xLine)->SetProperty, Color=self->Get("Ccrosshair"), Thick=1,
DATA=[[scaledX, yrange[0], 0], [scaledX, yrange[1], 0]]
*(yLine)->SetProperty, Color=self->Get("Ccrosshair"), Thick=1,
DATA=[[xrange[0], scaledY, 0], [xrange[1], scaledY, 0]]
============================================================ ====
Look at the img to get my point:
http://sophorus.mine.nu/idlgrplot_cursorpos.jpg
If someone with a fresh mind has any suggestions: please...
Thanks a bunch..
Laurens
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| Re: IDLgrPlot and Widget event [message #54212 is a reply to message #54140] |
Sat, 26 May 2007 07:12  |
Laurens
Messages: 41
Registered: May 2006
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Member |
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David Fanning wrote:
> Laurens writes:
>
>> After much irritation from not being able to write a universal class for
>> drawing every kind of curve, (as usual) David's suggestion to me a few
>> months ago did the trick;
>>
>> All measures are normalized to 0->1 so Axis, Curve/Plot and Symbols, all
>> are scaled to that 0-> scale; the curve draws fine.
>>
>> Now, I am catching the MOTION event from the mouse cursor; I want to
>> have something like a crosshair to accentuate the position of the mouse
>> cursor (see link for example img).
>> Catching the event and drawing the polylines almost goed well, except
>> for the fact that I don't seem to be able to position the lines at the
>> right place. I guess this has to do since the event.x delivers me the
>> pixel-position on the widget, say 98. But 98 is a bit tough to fit onto
>> a scale of 0->1.
>>
>> So the actual question: how do I get from an event.x or event.y to a
>> position in my normalized plot?
>
> Unless I am missing something terribly obvious, don't you
> just divide the point by the size of the window in pixels
> to get the normalized location?
>
> dims = oWindow -> GetDimensions()
> xNormal = event.x / Float(dims[0])
> yNormal = event.y / Float(dims[1])
>
> Cheers,
>
> David
grrrr, You're not the one who is missing the obvious :) Though it's not
an exact match to what I need (there seems to be some difference in
y-direction, but I guess that's because the curve is smaller than the
viewplane...
Anyhow; thanks mate ;)
Cheers, Laurens
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| Re: IDLgrPlot and Widget event [message #54237 is a reply to message #54140] |
Fri, 25 May 2007 09:03 |
David Fanning
Messages: 11724
Registered: August 2001
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Senior Member |
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Laurens writes:
> After much irritation from not being able to write a universal class for
> drawing every kind of curve, (as usual) David's suggestion to me a few
> months ago did the trick;
>
> All measures are normalized to 0->1 so Axis, Curve/Plot and Symbols, all
> are scaled to that 0-> scale; the curve draws fine.
>
> Now, I am catching the MOTION event from the mouse cursor; I want to
> have something like a crosshair to accentuate the position of the mouse
> cursor (see link for example img).
> Catching the event and drawing the polylines almost goed well, except
> for the fact that I don't seem to be able to position the lines at the
> right place. I guess this has to do since the event.x delivers me the
> pixel-position on the widget, say 98. But 98 is a bit tough to fit onto
> a scale of 0->1.
>
> So the actual question: how do I get from an event.x or event.y to a
> position in my normalized plot?
Unless I am missing something terribly obvious, don't you
just divide the point by the size of the window in pixels
to get the normalized location?
dims = oWindow -> GetDimensions()
xNormal = event.x / Float(dims[0])
yNormal = event.y / Float(dims[1])
Cheers,
David
--
David Fanning, Ph.D.
Fanning Software Consulting, Inc.
Coyote's Guide to IDL Programming: http://www.dfanning.com/
Sepore ma de ni thui. ("Perhaps thou speakest truth.")
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