Greetings everyone, I'm a novice plpgsql user. For an application, I'm trying to write a user-defined function that takes a row of some table (let's say with k fields) and takes another row from another table (again with k fields); then calculate the Euclidean, Manhattan or generally Minkowski distance (with some p) and then return an integer. I've written this:
CREATE FUNCTION euclidean_distance(row1 table_train, row2 table_test, OUT distance DOUBLE PRECISION) AS $$ DECLARE tmp DOUBLE PRECISION; BEGIN FOR col IN SELECT column_name FROM information_schema.columns WHERE table_name=table_train LOOP tmp := (row1.col - row2.col); distance += tmp*tmp; END LOOP; distance := sqrt(distance); END; $$ LANGUAGE plpgsql; Could anyone please help me fix this function so that I can pass any two rows of two tables (with same number of columns) and have their distance returned. Best regards, Babak Alipour -- *Babak Alipour ,* *University of Florida*
