Making an OTU table (otutab command)
Convert OTU table from frequencies to counts. The input file must be in QIIME classic format except that the table entries are floating point frequencies in the range 0 to 1.
The output file is specified by the -output option. It is written in QIIME classic format.
The desired total count for each sample is specified by the -sample_size option, default 10000.
A frequency is converted to a count using count = frequency * sample_size and rounding to the nearest integer. The total after conversion may be slightly different from sample_size due to rounding.
usearch -otutab_freqs2counts otutable_freqs.txt -output otutable_counts.txt