001 package edu.nrao.sss.astronomy;
002
003 import java.math.BigDecimal;
004 import java.math.RoundingMode;
005 import java.util.Calendar;
006 import java.util.Date;
007
008 import edu.nrao.sss.measure.ArcUnits;
009 import edu.nrao.sss.measure.Latitude;
010 import edu.nrao.sss.measure.Distance;
011 import edu.nrao.sss.measure.DistanceUnits;
012 import edu.nrao.sss.measure.LinearVelocity;
013 import edu.nrao.sss.measure.LinearVelocityUnits;
014 import edu.nrao.sss.measure.Longitude;
015
016 /**
017 * Helper for test classes; builds an ephemeris table.
018 * <p>
019 * <b>Version Info:</b>
020 * <table style="margin-left:2em">
021 * <tr><td>$Revision: 1314 $</td></tr>
022 * <tr><td>$Date: 2008-05-30 11:31:14 -0600 (Fri, 30 May 2008) $</td></tr>
023 * <tr><td>$Author: dharland $</td></tr>
024 * </table></p>
025 *
026 * @since 2006-10-02
027 */
028 public class EphemerisTableBuilder
029 {
030 private Latitude decStart, decEnd;
031 private Longitude raStart, raEnd;
032 private Distance distStart, distEnd;
033 private LinearVelocity velocityStart, velocityEnd;
034 private Date dateStart, dateEnd;
035
036 private int tableSize;
037
038 public void setDeclinationRange(Latitude first, Latitude last)
039 {
040 decStart = first;
041 decEnd = last;
042 }
043
044 public void setRightAscensionRange(Longitude first, Longitude last)
045 {
046 raStart = first;
047 raEnd = last;
048 }
049
050 public void setDistanceRange(Distance first, Distance last)
051 {
052 distStart = first;
053 distEnd = last;
054 }
055
056 public void setVelocityRange(LinearVelocity first, LinearVelocity last)
057 {
058 velocityStart = first;
059 velocityEnd = last;
060 }
061
062 public void setDateRange(Date first, Date last)
063 {
064 dateStart = first;
065 dateEnd = last;
066 }
067
068 public void setTableSize(int numberOfEntries)
069 {
070 tableSize = numberOfEntries;
071 }
072
073 public EphemerisTable makeTable()
074 {
075 EphemerisTable table = new EphemerisTable();
076
077 table.setOriginOfInformation("EphemerisTableBuilder.java");
078
079 int count = (tableSize > 0) ? tableSize : 10 + (int)(10.0 * Math.random());
080
081 BigDecimal divisor = new BigDecimal(count - (count > 1 ? 1 : 0));
082
083 Calendar cal = Calendar.getInstance();
084 Date[] dates = getDates();
085 long date = dates[0].getTime();
086 long dateIncr = (dates[1].getTime() - date) / divisor.longValue();
087
088 Latitude[] decs = getDeclinations();
089 BigDecimal decDegrees = decs[0].toUnits(ArcUnits.DEGREE);
090 BigDecimal decIncr = decs[1].toUnits(ArcUnits.DEGREE)
091 .subtract(decDegrees).divide(divisor, RoundingMode.HALF_UP);
092
093 Longitude[] ras = getRightAscensions();
094 BigDecimal raDegrees = ras[0].toUnits(ArcUnits.DEGREE);
095 BigDecimal raIncr = ras[1].toUnits(ArcUnits.DEGREE)
096 .subtract(raDegrees).divide(divisor, RoundingMode.HALF_UP);
097
098 Distance[] dists = getDistances();
099 BigDecimal au = dists[0].toUnits(DistanceUnits.ASTRONOMICAL_UNIT);
100 BigDecimal auIncr = dists[1].toUnits(DistanceUnits.ASTRONOMICAL_UNIT)
101 .subtract(au).divide(divisor, RoundingMode.HALF_UP);
102
103 LinearVelocity[] speeds = getVelocities();
104 BigDecimal kms = speeds[0].toUnits(LinearVelocityUnits.KILOMETERS_PER_SECOND);
105 BigDecimal kmsIncr = speeds[1].toUnits(LinearVelocityUnits.KILOMETERS_PER_SECOND)
106 .subtract(kms).divide(divisor, RoundingMode.HALF_UP);
107
108 for (int e=0; e < count; e++)
109 {
110 EphemerisTableEntry entry = new EphemerisTableEntry();
111
112 cal.setTimeInMillis(date);
113 entry.setTime(cal.getTime());
114 date += dateIncr;
115
116 entry.setLatitude(new Latitude(decDegrees));
117 decDegrees = decDegrees.add(decIncr);
118
119 entry.setLongitude(new Longitude(raDegrees));
120 raDegrees = raDegrees.add(raIncr);
121
122 entry.setDistance(new Distance(au, DistanceUnits.ASTRONOMICAL_UNIT));
123 au = au.add(auIncr);
124
125 entry.setVelocity(new LinearVelocity(kms));
126 kms.add(kmsIncr);
127
128 table.add(entry);
129 }
130
131 return table;
132 }
133
134 private Latitude[] getDeclinations()
135 {
136 Latitude[] decs = new Latitude[2];
137
138 decs[0] = (decStart == null) ?
139 new Latitude(Double.toString(-90.0 + 180.0 * Math.random())) : decStart;
140
141 decs[1] = (decEnd == null) ?
142 new Latitude(Double.toString(-90.0 + 180.0 * Math.random())) : decEnd;
143
144 return decs;
145 }
146
147 private Longitude[] getRightAscensions()
148 {
149 Longitude[] ras = new Longitude[2];
150
151 ras[0] = (raStart == null) ?
152 new Longitude(Double.toString(360.0 * Math.random())) : raStart;
153
154 ras[1] = (raEnd == null) ?
155 new Longitude(Double.toString(360.0 * Math.random())) : raEnd;
156
157 return ras;
158 }
159
160 private Distance[] getDistances()
161 {
162 Distance[] dists = new Distance[2];
163
164 dists[0] = (distStart == null) ?
165 new Distance(Double.toString(3.0 + 47.0 * Math.random()),
166 DistanceUnits.ASTRONOMICAL_UNIT) : distStart;
167
168 dists[1] = (distEnd == null) ?
169 new Distance(Double.toString(3.0 + 47.0 * Math.random()),
170 DistanceUnits.ASTRONOMICAL_UNIT) : distEnd;
171
172 return dists;
173 }
174
175 private LinearVelocity[] getVelocities()
176 {
177 LinearVelocity[] speeds = new LinearVelocity[2];
178
179 speeds[0] = (velocityStart == null) ?
180 new LinearVelocity(Double.toString(-100.0 + 200.0 * Math.random())) : velocityStart;
181
182 speeds[1] = (velocityEnd == null) ?
183 new LinearVelocity(Double.toString(-100.0 + 200.0 * Math.random())) : velocityEnd;
184
185 return speeds;
186 }
187
188 private Date[] getDates()
189 {
190 Date[] dates = new Date[2];
191
192 Calendar cal = Calendar.getInstance();
193
194 if ((dateStart != null) && (dateEnd != null))
195 {
196 dates[0] = dateStart;
197 dates[1] = dateEnd;
198 }
199 else if ((dateStart != null) && (dateEnd == null))
200 {
201 cal.setTime(dateStart);
202 cal.add(Calendar.MONTH, 3);
203 dates[0] = dateStart;
204 dates[1] = cal.getTime();
205 }
206 else if ((dateStart == null) && (dateEnd != null))
207 {
208 cal.setTime(dateEnd);
209 cal.add(Calendar.MONTH, -3);
210 dates[0] = cal.getTime();
211 dates[1] = dateEnd;
212 }
213 else //if ((dateStart == null) && (dateEnd == null))
214 {
215 dates[0] = cal.getTime();
216 cal.add(Calendar.MONTH, 3);
217 dates[1] = cal.getTime();
218 }
219
220 return dates;
221 }
222 /*
223 public static void main(String[] args)
224 {
225 EphemerisTableBuilder etb = new EphemerisTableBuilder();
226 System.out.println(etb.makeTable());
227 }
228 */
229 }