/**
* this method draws a sample of size endPercent-startPercent and returns the size of this sample
* which corresponds to the number of content items
*/
public static double drawSample(int forumID, int startPercent, int endPercent) {
if (!distributionsPerForumMap.containsKey(
String.valueOf(forumID) + String.valueOf(startPercent) + String.valueOf(endPercent))) {
ForumDistribution sampledForumDistribution = new ForumDistribution();
ArrayList<Integer> threadLengths = threadsPerForumMap.get(forumID);
Integer numberOfThreads = threadLengths.size();
Integer startIndex;
if (startPercent == 0.0) {
startIndex = 0;
} else {
startIndex = (int) Math.round((startPercent / (double) 100) * numberOfThreads) - 1;
}
Integer endIndex = (int) Math.round((endPercent / (double) 100) * numberOfThreads) - 1;
for (int i = startIndex; i <= endIndex; i++) {
sampledForumDistribution.addThread(threadLengths.get(i));
}
distributionsPerForumMap.put(
String.valueOf(forumID) + String.valueOf(startPercent) + String.valueOf(endPercent),
sampledForumDistribution);
dumpDistributionToFile(sampledForumDistribution, forumID, startPercent, endPercent);
return (double) sampledForumDistribution.getNumberOfContentItems();
} else {
return (double)
distributionsPerForumMap
.get(
String.valueOf(forumID)
+ String.valueOf(startPercent)
+ String.valueOf(endPercent))
.getNumberOfContentItems();
}
}
public static double getNewThreadProb(int forumID, int startPercent, int endPercent) {
ForumDistribution forumDistr =
distributionsPerForumMap.get(
String.valueOf(forumID) + String.valueOf(startPercent) + String.valueOf(endPercent));
return forumDistr.getNumberOfThreads() / (double) forumDistr.getNumberOfContentItems();
}
