Report  pgrandomness released on pgFoundry
Today I released the project pgrandomness on pgFoundry. This project provides C language functions to PostgreSQL that support some statistical calculations to determine the randomness of data (in the bytea format), such as:
Any feedback is welcome! By the way: There is a quick solution in case you need to concatenate many bytea values using an aggregate function. For example, suppose you would like to calculate the entropy of a all bytea values in your table concatenated. Note that this cannot be done by simply calculating the entropy valuewise and using the average entropy as total entropy. What you'd like to do is something like the following: SELECT byte_entropy(bytea_concat(my_data)) GROUP BY xyz; Since there is no bytea_concat aggregate function per se, define it first using the following statement: bytea x := bytea_concat(bytea) aggregation function
CREATE AGGREGATE bytea_concat (bytea) ( sfunc = byteacat, stype = bytea, initcond = '' );
Yours
