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desruisseaux pushed a commit to branch geoapi-4.0
in repository https://gitbox.apache.org/repos/asf/sis.git
The following commit(s) were added to refs/heads/geoapi-4.0 by this push:
new f0f7cc4 Replace the algorithm for default NTv2 accuracy by a
hard-coded value for 1 cm on Earth. The rational is that it is very difficult
to guess what is the accuracy. Statistics like the average difference between
values can give very different values. With hard-coded default value, at least
we know what it means.
f0f7cc4 is described below
commit f0f7cc4ff620b9fd66786611fd3e956b5a1b50cf
Author: Martin Desruisseaux <[email protected]>
AuthorDate: Sun Oct 14 19:41:00 2018 +0200
Replace the algorithm for default NTv2 accuracy by a hard-coded value for 1
cm on Earth.
The rational is that it is very difficult to guess what is the accuracy.
Statistics like the average difference between values can give very
different values.
With hard-coded default value, at least we know what it means.
---
.../provider/DatumShiftGridCompressed.java | 4 ++--
.../referencing/provider/DatumShiftGridFile.java | 6 ++++--
.../sis/internal/referencing/provider/NTv2.java | 19 ++++---------------
3 files changed, 10 insertions(+), 19 deletions(-)
diff --git
a/core/sis-referencing/src/main/java/org/apache/sis/internal/referencing/provider/DatumShiftGridCompressed.java
b/core/sis-referencing/src/main/java/org/apache/sis/internal/referencing/provider/DatumShiftGridCompressed.java
index 2fb393a..ee1e644 100644
---
a/core/sis-referencing/src/main/java/org/apache/sis/internal/referencing/provider/DatumShiftGridCompressed.java
+++
b/core/sis-referencing/src/main/java/org/apache/sis/internal/referencing/provider/DatumShiftGridCompressed.java
@@ -112,7 +112,7 @@ final class DatumShiftGridCompressed<C extends Quantity<C>,
T extends Quantity<T
c -= average;
c -= (compressed[i] = (short) Math.round(c));
if (!(Math.abs(c) < tolerance)) { // Use
'!' for catching NaN values.
- return grid; // Can not compress.
+ return grid; // Can
not compress.
}
}
data[dim] = compressed;
@@ -196,7 +196,7 @@ final class DatumShiftGridCompressed<C extends Quantity<C>,
T extends Quantity<T
if (iy < 0) {
iy = 0;
gridY = -1;
- } else if (iy > ymax) { // Subtraction of 2 already done by the
constructor.
+ } else if (iy > ymax) { // Subtraction of 2 already done
by the constructor.
iy = ymax;
gridY = +1;
}
diff --git
a/core/sis-referencing/src/main/java/org/apache/sis/internal/referencing/provider/DatumShiftGridFile.java
b/core/sis-referencing/src/main/java/org/apache/sis/internal/referencing/provider/DatumShiftGridFile.java
index cf1439d..0e11997 100644
---
a/core/sis-referencing/src/main/java/org/apache/sis/internal/referencing/provider/DatumShiftGridFile.java
+++
b/core/sis-referencing/src/main/java/org/apache/sis/internal/referencing/provider/DatumShiftGridFile.java
@@ -345,7 +345,9 @@ public abstract class DatumShiftGridFile<C extends
Quantity<C>, T extends Quanti
private static final long serialVersionUID = -9221609983475286496L;
/**
- * The translation values.
+ * The translation values. {@code offsets.length} is the number of
dimensions, and {@code offsets[dim].length}
+ * shall be the same for all {@code dim} value. Component {@code dim}
of the translation vector at coordinate
+ * {@code gridX}, {@code gridY} is {@code offsets[dim][gridX +
gridY*nx]}.
*/
final float[][] offsets;
@@ -399,7 +401,7 @@ public abstract class DatumShiftGridFile<C extends
Quantity<C>, T extends Quanti
}
/**
- * Returns the number of shift dimension.
+ * Returns the number of shift dimensions.
*/
@Override
public final int getTranslationDimensions() {
diff --git
a/core/sis-referencing/src/main/java/org/apache/sis/internal/referencing/provider/NTv2.java
b/core/sis-referencing/src/main/java/org/apache/sis/internal/referencing/provider/NTv2.java
index baf0c4c..d4a6767 100644
---
a/core/sis-referencing/src/main/java/org/apache/sis/internal/referencing/provider/NTv2.java
+++
b/core/sis-referencing/src/main/java/org/apache/sis/internal/referencing/provider/NTv2.java
@@ -45,6 +45,7 @@ import
org.opengis.referencing.operation.NoninvertibleTransformException;
import org.apache.sis.referencing.operation.transform.InterpolatedTransform;
import org.apache.sis.internal.system.Loggers;
import org.apache.sis.internal.system.DataDirectory;
+import org.apache.sis.internal.referencing.Formulas;
import org.apache.sis.parameter.ParameterBuilder;
import org.apache.sis.parameter.Parameters;
import org.apache.sis.util.collection.Cache;
@@ -167,7 +168,7 @@ public final class NTv2 extends AbstractProvider {
*
* @author Simon Reynard (Geomatys)
* @author Martin Desruisseaux (Geomatys)
- * @version 0.7
+ * @version 1.0
* @since 0.7
* @module
*/
@@ -345,22 +346,10 @@ public final class NTv2 extends AbstractProvider {
/*
* We need an estimation of translation accuracy, in order to
decide when to stop iterations
* during inverse transformations. If we did not found that
information in the file, compute
- * an arbitrary default accuracy derived from the variations found
in actual values.
+ * an arbitrary default accuracy.
*/
if (Double.isNaN(grid.accuracy)) {
- double txmin = Double.POSITIVE_INFINITY;
- double txmax = Double.NEGATIVE_INFINITY;
- double tymin = Double.POSITIVE_INFINITY;
- double tymax = Double.NEGATIVE_INFINITY;
- for (int i=Math.min(tx.length, ty.length); --i >= 0;) {
- double x = tx[i];
- double y = ty[i];
- if (x < txmin) txmin = x;
- if (x > txmax) txmax = x;
- if (y < tymin) tymin = y;
- if (y > tymax) tymax = y;
- }
- grid.accuracy = Math.min(txmax - txmin, tymax - tymin) / 1000;
+ grid.accuracy =
Units.DEGREE.getConverterTo(unit).convert(Formulas.ANGULAR_TOLERANCE);
}
header.keySet().retainAll(Arrays.asList(overviewKeys)); // Keep
only overview records.
return DatumShiftGridCompressed.compress(grid, null, precision /
Math.max(dx, dy));
