Previous: Keyword Commands, Up: Debugging [Contents][Index]
Default value: false
When debugmode is true, Maxima will start the Maxima debugger
when a Maxima error occurs. At this point the user may enter commands to
examine the call stack, set breakpoints, step through Maxima code, and so on.
See debugging for a list of Maxima debugger commands.
When debugmode is lisp, Maxima will start the Lisp debugger
when a Maxima error occurs.
In either case, enabling debugmode will not catch Lisp errors.
Default value: false
When refcheck is true, Maxima prints a message
each time a bound variable is used for the first time in a
computation.
Default value: false
If setcheck is set to a list of variables (which can
be subscripted),
Maxima prints a message whenever the variables, or
subscripted occurrences of them, are bound with the
ordinary assignment operator :, the :: assignment
operator, or function argument binding,
but not the function assignment := nor the macro assignment
::= operators.
The message comprises the name of the variable and the
value it is bound to.
setcheck may be set to all or true thereby
including all variables.
Each new assignment of setcheck establishes a new list of variables to
check, and any variables previously assigned to setcheck are forgotten.
The names assigned to setcheck must be quoted if they would otherwise
evaluate to something other than themselves.
For example, if x, y, and z are already bound, then enter
setcheck: ['x, 'y, 'z]$
to put them on the list of variables to check.
No printout is generated when a
variable on the setcheck list is assigned to itself, e.g., X: 'X.
Default value: false
When setcheckbreak is true,
Maxima will present a break prompt
whenever a variable on the setcheck list is assigned a new value.
The break occurs before the assignment is carried out.
At this point, setval holds the value to which the variable is
about to be assigned.
Hence, one may assign a different value by assigning to setval.
Holds the value to which a variable is about to be set when
a setcheckbreak occurs.
Hence, one may assign a different value by assigning to setval.
See also setcheck and setcheckbreak.
Given functions f_1, …, f_n, timer puts each one on the
list of functions for which timing statistics are collected.
timer(f)$ timer(g)$ puts f and then g onto the list;
the list accumulates from one call to the next.
timer(all) puts all user-defined functions (as named by the global
variable functions) on the list of timed functions.
With no arguments, timer returns the list of timed functions.
Maxima records how much time is spent executing each function
on the list of timed functions.
timer_info returns the timing statistics, including the
average time elapsed per function call, the number of calls, and the
total time elapsed.
untimer removes functions from the list of timed functions.
timer quotes its arguments.
f(x) := x^2$ g:f$ timer(g)$ does not put f on the timer list.
If trace(f) is in effect, then timer(f) has no effect;
trace and timer cannot both be in effect at the same time.
See also timer_devalue.
Given functions f_1, …, f_n,
untimer removes each function from the timer list.
With no arguments, untimer removes all functions currently on the timer
list.
After untimer (f) is executed, timer_info (f) still returns
previously collected timing statistics,
although timer_info() (with no arguments) does not
return information about any function not currently on the timer list.
timer (f) resets all timing statistics to zero
and puts f on the timer list again.
Default value: false
When timer_devalue is true, Maxima subtracts from each timed
function the time spent in other timed functions. Otherwise, the time reported
for each function includes the time spent in other functions.
Note that time spent in untimed functions is not subtracted from the
total time.
See also timer and timer_info.
Given functions f_1, ..., f_n, timer_info returns a matrix
containing timing information for each function.
With no arguments, timer_info returns timing information for
all functions currently on the timer list.
The matrix returned by timer_info contains the function name,
time per function call, number of function calls, total time,
and gctime, which meant "garbage collection time" in the original Macsyma
but is now always zero.
The data from which timer_info constructs its return value
can also be obtained by the get function:
get(f, 'calls); get(f, 'runtime); get(f, 'gctime);
See also timer.
Given functions f_1, …, f_n, trace instructs Maxima to
print out debugging information whenever those functions are called.
trace(f)$ trace(g)$ puts f and then g onto the list of
functions to be traced; the list accumulates from one call to the next.
trace(all) puts all user-defined functions (as named by the global
variable functions) on the list of functions to be traced.
With no arguments,
trace returns a list of all the functions currently being traced.
The untrace function disables tracing.
See also trace_options.
trace quotes its arguments. Thus,
f(x) := x^2$ g:f$ trace(g)$ does not put f on the trace list.
When a function is redefined, it is removed from the timer list.
Thus after timer(f)$ f(x) := x^2$,
function f is no longer on the timer list.
If timer (f) is in effect, then trace (f) has no effect;
trace and timer can’t both be in effect for the same function.
Sets the trace options for function f.
Any previous options are superseded.
trace_options (f, ...) has no effect unless trace (f)
is also called (either before or after trace_options).
trace_options (f) resets all options to their default values.
The option keywords are:
noprint
Do not print a message at function entry and exit.
break
Put a breakpoint before the function is entered,
and after the function is exited. See break.
lisp_print
Display arguments and return values as Lisp objects.
info
Print -> true at function entry and exit.
errorcatch
Catch errors, giving the option to signal an error,
retry the function call, or specify a return value.
Trace options are specified in two forms. The presence of the option
keyword alone puts the option into effect unconditionally.
(Note that option foo is not put into effect by specifying
foo: true or a similar form; note also that keywords need not
be quoted.) Specifying the option keyword with a predicate
function makes the option conditional on the predicate.
The argument list to the predicate function is always
[level, direction, function, item] where level is the recursion
level for the function, direction is either enter or exit,
function is the name of the function, and item is the argument
list (on entering) or the return value (on exiting).
Here is an example of unconditional trace options:
(%i1) ff(n) := if equal(n, 0) then 1 else n * ff(n - 1)$ (%i2) trace (ff)$ (%i3) trace_options (ff, lisp_print, break)$ (%i4) ff(3);
Here is the same function, with the break option conditional
on a predicate:
(%i5) trace_options (ff, break(pp))$
(%i6) pp (level, direction, function, item) := block (print (item),
return (function = 'ff and level = 3 and direction = exit))$
(%i7) ff(6);
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