sharpetronics/QGIS
1
0
Fork 0
mirror of https://github.com/qgis/QGIS.git synced 2025-03-03 00:02:25 -05:00
Code Issues Packages Projects Releases Wiki Activity

Raster quantile: increase sample size

Browse Source 
Fixes #35465 (part two)
This commit is contained in:
Alessandro Pasotti 2020-04-19 19:00:31 +02:00
parent 970149f13e
commit ebdb546c10
2 changed files with 9 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
src/core/raster/qgscolorrampshader.cpp
View File

@ -204,11 +204,12 @@ void QgsColorRampShader::classifyColorRamp( const int classes, const int band, c
{
// Quantile
if ( band < 0 || !input )
return; // quantile classificationr requires a valid band, minMaxOrigin, and input
return; // quantile classification requires a valid band, minMaxOrigin, and input
double cut1 = std::numeric_limits<double>::quiet_NaN();
double cut2 = std::numeric_limits<double>::quiet_NaN();
const int sampleSize = 250000;
// Note: the sample size in other parts of QGIS appears to be 25000, it is ten times here.
const int sampleSize = 250000 * 10;
// set min and max from histogram, used later to calculate number of decimals to display
input->cumulativeCut( band, 0.0, 1.0, min, max, extent, sampleSize );

9
src/core/raster/qgsrasterinterface.cpp
View File

@ -352,7 +352,6 @@ void QgsRasterInterface::initHistogram( QgsRasterHistogram &histogram,
// Because it is easier to define fixed lower value for the chart, we calc optimum binCount
// for higher resolution (to avoid calculating that where histogram() is used. In any any case,
// it does not make sense to use more than width*height;
myBinCount = std::min( 2000, histogram.width * histogram.height );
// for Int16/Int32 make sure bin count <= actual range, because there is no sense in having
// bins at fractional values
@ -360,8 +359,12 @@ void QgsRasterInterface::initHistogram( QgsRasterHistogram &histogram,
mySrcDataType == Qgis::Int16 || mySrcDataType == Qgis::Int32 ||
mySrcDataType == Qgis::UInt16 || mySrcDataType == Qgis::UInt32 ) )
{
if ( myBinCount > histogram.maximum - histogram.minimum + 1 )
myBinCount = int( std::ceil( histogram.maximum - histogram.minimum + 1 ) );
myBinCount = std::min( histogram.width * histogram.height, static_cast<int>( std::ceil( histogram.maximum - histogram.minimum + 1 ) ) );
}
else
{
// This is for not integer types:
myBinCount = std::min( 2000, histogram.width * histogram.height );
}
}
}