Octave supports profiling of code execution on a per-function level. If profiling is enabled, each call to a function (supporting built-ins, operators, functions in oct- and mex-files, user-defined functions in Octave code and anonymous functions) is recorded while running Octave code. After that, this data can aid in analyzing the code behavior, and is in particular helpful for finding “hot spots” in the code which use up a lot of computation time and are the best targets to spend optimization efforts on.
The main command for profiling is
profile, which can be used to
start or stop the profiler and also to query collected data afterwards.
The data is returned in an Octave data structure which can then be
examined or further processed by other routines or tools.
Control the built-in profiler.
Start the profiler, clearing all previously collected data if there is any.
Stop profiling. The collected data can later be retrieved and examined
T = profile ("info").
Clear all collected profiler data.
Restart profiling without clearing the old data. All newly collected statistics are added to the existing ones.
S = profile ("status")
Return a structure with information about the current status of the profiler.
At the moment, the only field is
ProfilerStatus which is either
T = profile ("info")
Return the collected profiling statistics in the structure T. The
flat profile is returned in the field
FunctionTable which is an
array of structures, each entry corresponding to a function which was called
and for which profiling statistics are present. In addition, the field
Hierarchical contains the hierarchical call tree. Each node has an
index into the
FunctionTable identifying the function it corresponds
to as well as data fields for number of calls and time spent at this level
in the call tree.
See also: profshow, profexplore.
An easy way to get an overview over the collected data is
profshow. This function takes the profiler data returned by
profile as input and prints a flat profile, for instance:
Function Attr Time (s) Calls ---------------------------------------- >myfib R 2.195 13529 binary <= 0.061 13529 binary - 0.050 13528 binary + 0.026 6764
This shows that most of the run time was spent executing the function ‘myfib’, and some minor proportion evaluating the listed binary operators. Furthermore, it is shown how often the function was called and the profiler also records that it is recursive.
Display flat per-function profiler results.
Print out profiler data (execution time, number of calls) for the most critical n functions. The results are sorted in descending order by the total time spent in each function. If n is unspecified it defaults to 20.
The input data is the structure returned by
profshow will use the current profile dataset.
The attribute column displays ‘R’ for recursive functions, and is blank for all other function types.
See also: profexplore, profile.
Interactively explore hierarchical profiler output.
Assuming data is the structure with profile data returned by
profile (, this command opens an interactive prompt
that can be used to explore the call-tree. Type help to get a list
of possible commands. If data is omitted,
is called and used in its place.
See also: profile, profshow.