Class Arrays

Description:

Functions which operate on array-valued cells. The array parameters of these functions can only be used on values which are already arrays (usually, numeric arrays). In most cases that means on values in table columns which are declared as array-valued. FITS and VOTable tables can have columns which contain array values, but other formats such as CSV cannot.

The functions fall into a number of categories:

• Aggregating operations, which map an array value to a scalar, including size, count, maximum, minimum, sum, mean, median, quantile, stdev, variance, join.
• Operations on one or more arrays which produce array results, including add, subtract, multiply, divide, reciprocal, condition.
• A set of functions named array with various numbers of arguments, which let you assemble an array value from a list of scalar numbers. This can be used for instance to get the mean of a set of three magnitudes by using an expression like "mean(array(jmag, hmag, kmag))".