Dynamic usage of APL primitive functions

Dynamic measurements of APL primitive functions and operators applied to shaped data objects (arrays) are routinely collected by the Burroughs APL/700 system. Actual usage of these primitives by all APL users is counted. Data collected from two sites is contrasted. The mixed functions (that apply to the structure of shaped data objects) were used about twice as frequently as the scalar functions (that apply to the values of shaped data objects). The scalar functions were used about twice as frequently as indexing. The combined data from the two sites is found to closely match independent static data previously obtained from analysis of defined functions in workspaces.