[analysis] fix derivative filter z factor handling (#5073)

nirvn · web-flow · commit 74306c7d50b1 · 2017-08-25T17:19:59.000+07:00
diff --git a/src/analysis/raster/qgsderivativefilter.cpp b/src/analysis/raster/qgsderivativefilter.cpp
@@ -92,7 +92,7 @@ float QgsDerivativeFilter::calcFirstDerX( float* x11, float* x21, float* x31, fl
     return mOutputNodataValue;
   }
 
-  return sum / ( weight * mCellSizeX * mZFactor );
+  return sum / ( weight * mCellSizeX ) * mZFactor;
 }
 
 float QgsDerivativeFilter::calcFirstDerY( float* x11, float* x21, float* x31, float* x12, float* x22, float* x32, float* x13, float* x23, float* x33 )
@@ -159,7 +159,7 @@ float QgsDerivativeFilter::calcFirstDerY( float* x11, float* x21, float* x31, fl
     return mOutputNodataValue;
   }
 
-  return sum / ( weight * mCellSizeY * mZFactor );
+  return sum / ( weight * mCellSizeY ) * mZFactor;
 }
 
 

Original file line number	Diff line number	Diff line change
`@@ -92,7 +92,7 @@ float QgsDerivativeFilter::calcFirstDerX( float* x11, float* x21, float* x31, fl`
`92`	`92`	`return mOutputNodataValue;`
`93`	`93`	`}`
`94`	`94`
`95`		`- return sum / ( weight * mCellSizeX * mZFactor );`
	`95`	`+ return sum / ( weight * mCellSizeX ) * mZFactor;`
`96`	`96`	`}`
`97`	`97`
`98`	`98`	`float QgsDerivativeFilter::calcFirstDerY( float* x11, float* x21, float* x31, float* x12, float* x22, float* x32, float* x13, float* x23, float* x33 )`
`@@ -159,7 +159,7 @@ float QgsDerivativeFilter::calcFirstDerY( float* x11, float* x21, float* x31, fl`
`159`	`159`	`return mOutputNodataValue;`
`160`	`160`	`}`
`161`	`161`
`162`		`- return sum / ( weight * mCellSizeY * mZFactor );`
	`162`	`+ return sum / ( weight * mCellSizeY ) * mZFactor;`
`163`	`163`	`}`
`164`	`164`
`165`	`165`