I'm running CreateSequenceDictionary on a Windows 10 machine with 4 gigabytes of ram and more than 50 gigabytes of free disk space, while my human dna reference file is nearly 3 gigabytes. The same problem does not appear whenever I use a very small fasta file made for demonstration purposes and the dict is normally created. Here's the error I keep getting
Runtime.totalMemory()=259522560
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Exception in thread "main" java.lang.OutOfMemoryError: Java heap space
at htsjdk.samtools.reference.IndexedFastaSequenceFile.getSubsequenceAt(IndexedFastaSequenceFile.java:185)
at htsjdk.samtools.reference.IndexedFastaSequenceFile.getSequence(IndexedFastaSequenceFile.java:164)
at htsjdk.samtools.reference.IndexedFastaSequenceFile.nextSequence(IndexedFastaSequenceFile.java:241)
at picard.sam.CreateSequenceDictionary.makeSequenceDictionary(CreateSequenceDictionary.java:141)
at picard.sam.CreateSequenceDictionary.doWork(CreateSequenceDictionary.java:121)
at picard.cmdline.CommandLineProgram.instanceMain(CommandLineProgram.java:183)
at picard.sam.CreateSequenceDictionary.main(CreateSequenceDictionary.java:97)