3.11.2 Recursion Depth

Calc uses recursion in many of its calculations. Emacs Lisp keeps a variable max-lisp-eval-depth which limits the amount of recursion possible in an attempt to recover from program bugs. If a calculation ever halts incorrectly with the message “Computation got stuck or ran too long,” use the M command (calc-more-recursion-depth) to increase this limit. (Of course, this will not help if the calculation really did get stuck due to some problem inside Calc.)

The limit is always increased (multiplied) by a factor of two. There is also an I M (calc-less-recursion-depth) command which decreases this limit by a factor of two, down to a minimum value of 200. The default value is 1000.

These commands also double or halve max-specpdl-size, another internal Lisp recursion limit. The minimum value for this limit is 600.