public void map(
LongWritable key,
Star value,
OutputCollector<BlockIDWritable, PairWritable> output,
Reporter reporter)
throws IOException {
loc.set(value.ra, value.dec);
int zoneNum = loc.zoneNum;
int raNum = loc.raNum;
p.set(value, null);
/*
* When the block size increases (> theta), only part of a block
* needs to be copied to its neighbor.
*/
output.collect(loc, p);
/*
* only replicate objects in the border of a block. I expect most of
* objects don't need to be copied.
*/
if (value.dec > zoneRanges[zoneNum][0] + theta
&& value.dec < zoneRanges[zoneNum][1] - theta
&& value.ra > blockRanges[raNum][0] + maxAlphas[zoneNum]
&& value.ra < blockRanges[raNum][1] - maxAlphas[zoneNum]) return;
/*
* the code below is to copy the star to some neighbors. We only
* need to copy an object to the bottom, left, left bottom, left top
* neighbors
*/
value.margin = true;
/*
* we should treat the entire zone 0 as a block, so we only needs to
* copy some objects at the corner to their neighbors
*/
if (loc.zoneNum == 0) {
/* copy the object to the right top neighbor */
if (value.ra >= blockRanges[raNum][1] - maxAlphas[zoneNum]
&& value.ra <= blockRanges[raNum][1]
&& value.dec >= zoneRanges[zoneNum][1] - theta
&& value.dec <= zoneRanges[zoneNum][1]) {
// BlockIDWritable loc1 = new BlockIDWritable();
/* raNum of objects in zone 0 is always 0,
* we need to recalculate it. */
// loc1.raNum = BlockIDWritable.ra2Num(value.ra) + 1;
// if (loc1.raNum == numBlocks) {
// loc1.raNum = 0;
// value.ra -= 360;
// }
// loc1.zoneNum = loc.zoneNum + 1;
/// output.collect(loc1, p);
}
return;
} else if (loc.zoneNum == numZones - 1) {
/* copy the object to the bottom neighbor */
if (value.dec >= zoneRanges[zoneNum][0] && value.dec <= zoneRanges[zoneNum][0] + theta) {
/* raNum of objects in zone zoneNum - 1 is always 0,
* we need to recalculate it. */
loc1.raNum = BlockIDWritable.ra2Num(value.ra);
loc1.zoneNum = loc.zoneNum - 1;
output.collect(loc1, p);
/* copy the object to the right bottom neighbor */
while (value.ra >= blockRanges[loc1.raNum][1] - maxAlphas[zoneNum]
&& value.ra <= blockRanges[loc1.raNum][1]) {
loc1.raNum++;
if (loc1.raNum == numBlocks) {
loc1.raNum = 0;
value.ra -= 360;
}
loc1.zoneNum = loc.zoneNum - 1;
output.collect(loc1, p);
}
}
return;
}
boolean wrap = false;
loc1.raNum = loc.raNum;
/* copy the object to the right neighbor */
while (value.ra >= blockRanges[loc1.raNum][1] - maxAlphas[zoneNum]
&& value.ra <= blockRanges[loc1.raNum][1]) {
loc1.raNum++;
loc1.zoneNum = loc.zoneNum;
/*
* when the object is copied to the right neighbor, we need to
* be careful. we need to convert ra and raNum if ra is close to
* 360.
*/
if (loc1.raNum == numBlocks) {
loc1.raNum = 0;
value.ra -= 360;
wrap = true;
}
output.collect(loc1, p);
/* copy the object to the right bottom neighbor */
if (value.dec >= zoneRanges[zoneNum][0] && value.dec <= zoneRanges[zoneNum][0] + theta) {
loc1.zoneNum = loc.zoneNum - 1;
output.collect(loc1, p);
}
/* copy the object to the right top neighbor */
if (value.dec >= zoneRanges[zoneNum][1] - theta && value.dec <= zoneRanges[zoneNum][1]) {
loc1.zoneNum = loc.zoneNum + 1;
output.collect(loc1, p);
}
}
if (wrap) {
value.ra += 360;
}
/* copy the object to the bottom neighbor */
if (value.dec >= zoneRanges[zoneNum][0] && value.dec <= zoneRanges[zoneNum][0] + theta) {
loc1.raNum = loc.raNum;
loc1.zoneNum = loc.zoneNum - 1;
if (loc1.zoneNum == 0) loc1.raNum = 0;
output.collect(loc1, p);
}
}
