//
// SphericalCoordinateSystem.java
//
/*
VisAD system for interactive analysis and visualization of numerical
data. Copyright (C) 1996 - 2017 Bill Hibbard, Curtis Rueden, Tom
Rink, Dave Glowacki, Steve Emmerson, Tom Whittaker, Don Murray, and
Tommy Jasmin.
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
MA 02111-1307, USA
*/
package visad;
/**
SphericalCoordinateSystem is the VisAD CoordinateSystem class
for (Latitude, Longitude, Radius) with a Cartesian Reference,
and with Latitude and Longitude in degrees.<P>
*/
public class SphericalCoordinateSystem extends CoordinateSystem {
private static Unit[] coordinate_system_units =
{CommonUnit.degree, CommonUnit.degree, null};
/** construct a CoordinateSystem for (latitude, longitude,
radius) relative to a 3-D Cartesian reference;
this constructor supplies units =
{CommonUnit.Degree, CommonUnit.Degree, null} to the super
constructor, in order to ensure Unit compatibility with its
use of trigonometric functions */
public SphericalCoordinateSystem(RealTupleType reference)
throws VisADException {
super(reference, coordinate_system_units);
}
/** trusted constructor for initializers */
SphericalCoordinateSystem(RealTupleType reference, boolean b) {
super(reference, coordinate_system_units, b);
}
public double[][] toReference(double[][] tuples) throws VisADException {
if (tuples == null || tuples.length != 3) {
throw new CoordinateSystemException("SphericalCoordinateSystem." +
"toReference: tuples wrong dimension");
}
int len = tuples[0].length;
double[][] value = new double[3][len];
for (int i=0; i<len ;i++) {
if (tuples[2][i] < 0.0) {
value[0][i] = Double.NaN;
value[1][i] = Double.NaN;
value[2][i] = Double.NaN;
}
else {
double coslat = Math.cos(Data.DEGREES_TO_RADIANS * tuples[0][i]);
double sinlat = Math.sin(Data.DEGREES_TO_RADIANS * tuples[0][i]);
double coslon = Math.cos(Data.DEGREES_TO_RADIANS * tuples[1][i]);
double sinlon = Math.sin(Data.DEGREES_TO_RADIANS * tuples[1][i]);
value[0][i] = tuples[2][i] * coslon * coslat;
value[1][i] = tuples[2][i] * sinlon * coslat;
value[2][i] = tuples[2][i] * sinlat;
}
}
return value;
}
public double[][] fromReference(double[][] tuples) throws VisADException {
if (tuples == null || tuples.length != 3) {
throw new CoordinateSystemException("SphericalCoordinateSystem." +
"fromReference: tuples wrong dimension");
}
int len = tuples[0].length;
double[][] value = new double[3][len];
for (int i=0; i<len ;i++) {
value[2][i] = Math.sqrt(tuples[0][i] * tuples[0][i] +
tuples[1][i] * tuples[1][i] +
tuples[2][i] * tuples[2][i]);
value[0][i] =
Data.RADIANS_TO_DEGREES * Math.asin(tuples[2][i] / value[2][i]);
value[1][i] =
Data.RADIANS_TO_DEGREES * Math.atan2(tuples[1][i], tuples[0][i]);
if (value[1][i] < 0.0) value[1][i] += 360.0;
}
return value;
}
public float[][] toReference(float[][] tuples) throws VisADException {
if (tuples == null || tuples.length != 3) {
throw new CoordinateSystemException("SphericalCoordinateSystem." +
"toReference: tuples wrong dimension");
}
int len = tuples[0].length;
float[][] value = new float[3][len];
for (int i=0; i<len ;i++) {
if (tuples[2][i] < 0.0) {
value[0][i] = Float.NaN;
value[1][i] = Float.NaN;
value[2][i] = Float.NaN;
}
else {
float coslat = (float) Math.cos(Data.DEGREES_TO_RADIANS * tuples[0][i]);
float sinlat = (float) Math.sin(Data.DEGREES_TO_RADIANS * tuples[0][i]);
float coslon = (float) Math.cos(Data.DEGREES_TO_RADIANS * tuples[1][i]);
float sinlon = (float) Math.sin(Data.DEGREES_TO_RADIANS * tuples[1][i]);
value[0][i] = tuples[2][i] * coslon * coslat;
value[1][i] = tuples[2][i] * sinlon * coslat;
value[2][i] = tuples[2][i] * sinlat;
}
}
return value;
}
public float[][] fromReference(float[][] tuples) throws VisADException {
if (tuples == null || tuples.length != 3) {
throw new CoordinateSystemException("SphericalCoordinateSystem." +
"fromReference: tuples wrong dimension");
}
int len = tuples[0].length;
float[][] value = new float[3][len];
for (int i=0; i<len ;i++) {
value[2][i] = (float) Math.sqrt(tuples[0][i] * tuples[0][i] +
tuples[1][i] * tuples[1][i] +
tuples[2][i] * tuples[2][i]);
value[0][i] = (float)
(Data.RADIANS_TO_DEGREES * Math.asin(tuples[2][i] / value[2][i]));
value[1][i] = (float)
(Data.RADIANS_TO_DEGREES * Math.atan2(tuples[1][i], tuples[0][i]));
if (value[1][i] < 0.0f) value[1][i] += 360.0f;
}
return value;
}
public static float[] getNormal(float[] xyz) throws VisADException {
CoordinateSystem cs = Display.DisplaySphericalCoordSys;
float[][] llrA = cs.fromReference(new float[][] {{xyz[0]}, {xyz[1]}, {xyz[2]}});
float[][] llrB = new float[][] {{llrA[0][0]}, {llrA[1][0]}, {llrA[2][0] + 1f}};
float[][] xyzB = cs.toReference(llrB);
float delX = xyzB[0][0] - xyz[0];
float delY = xyzB[1][0] - xyz[1];
float delZ = xyzB[2][0] - xyz[2];
float mag = (float) Math.sqrt(delX*delX+delY*delY+delZ*delZ);
return new float[] {delX/mag, delY/mag, delZ/mag};
}
public static float[] getUnitI(float[] xyz) throws VisADException {
CoordinateSystem cs = Display.DisplaySphericalCoordSys;
float[][] llrA = cs.fromReference(new float[][] {{xyz[0]}, {xyz[1]}, {xyz[2]}});
float[][] llrB = new float[][] {{llrA[0][0]}, {llrA[1][0] + 0.05f}, {llrA[2][0]}};
float[][] xyzB = cs.toReference(llrB);
float delX = xyzB[0][0] - xyz[0];
float delY = xyzB[1][0] - xyz[1];
float delZ = xyzB[2][0] - xyz[2];
float mag = (float) Math.sqrt(delX*delX+delY*delY+delZ*delZ);
return new float[] {delX/mag, delY/mag, delZ/mag};
}
public boolean equals(Object cs) {
return (cs instanceof SphericalCoordinateSystem);
}
}