Contour correction

[jwxiang]

When I check "Spectrogram, Contour Plot" example, I found that some contour lines close to the center of circle are not continues. There must be some wrong.

After go through "qwt_raster_data.cpp", I found 2 bugs:

1. intersect function:
case 6:
// e(-1,1,0), e(1,0,-1)
line[0] = vertex[1].toPoint();
line[1] = intersection( vertex[0], vertex[1] );
break;
should be:
case 6:
// e(-1,1,0), e(1,0,-1)
line[0] = vertex[2].toPoint();
line[1] = intersection( vertex[0], vertex[1] );
break;

2. contourLines function:
if ( ignoreOutOfRange )
{
if ( !range.contains( zMin ) || !range.contains( zMax ) )
continue;
}
this is not correct. How about rang.max>zMax and rang.min<zMin?
should be:
if ( ignoreOutOfRange )
{
if ( range.maxValue()<Min ) || range.minValue()> zMax ) )
continue;
}


After correcting, example works perfect.
before:
t1.png
After:
t2.png

[Uwe]

I have added a bug report see: https://sourceforge.net/tracker/?fun...93&atid=113693

Thanks for reporting,
Uwe

[Uwe]

should be: line[0] = vertex[2].toPoint();

Indeed, fixed in SVN: trunk and the 6.0 and 5.2 branches.

if ( ignoreOutOfRange )
{
if ( !range.contains( zMin ) || !range.contains( zMax ) )
continue;
}
this is not correct.

AFAIR IgnoreOutOfRange is a flag to filter out invalid values of raster data with gaps, that are indicated by some special value outside the valid range. Of course this is somehow mysterious and I couldn't hardly remember the use case myself ( I will add note to the docs ). So the code above is correct - even if being the reason for the missing lines in the example.

I modified the default setting of IgnoreOutOfRange ( to off ) in SVN trunk. For earlier versions I recommend to disable this flag in application code:

spectrogram->setConrecFlag( QwtRasterData::IgnoreOutOfRange, false );

spectrogram->setConrecFlag( QwtRasterData::IgnoreOutOfRange, false );

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Uwe