Undocumented Profiler options part 2

Three years ago I published an article on undocumented profiler options. Since then, I’ve posted several articles about performance tuning and profiling (for example, memory profiling) but nothing specifically about the Profiler. There are several additional undocumented aspects of the Profiler that I’d like to expose. Today’s article will focus on benefits that require a bit of tweaking to Matlab files (fixing a font issue and increasing the reported time resolution). Next week’s article will explain undocumented switches of the profile function, which can be used to profile built-in functions, as well as to provide detailed history timeline of the function calls.

Fixing a Profiler font problem

On my system, starting in R2012a, the code lines in the detailed profiling report look awful. The reason is that they are rendered using a proportional font, rather than the monospaced (fixed-width) font that is specified in the Matlab Preferences and used everywhere else (the Editor, Command Window etc.):

PRE {
  font-size: 100%;
}

with this one:

pre, tt {
  font-family: monospace
  font-size: 100%;
}

Increasing the reported timing resolution

The Profiler records information at a system-dependent time resolution, typically 1 millisecond. However, the profiling report only displays information at a granularity of 10 ms. I often find it useful to increase the reported resolution to 1 ms, and in fact the screenshots above reflect this change. This can easily be done by editing the profview function (%matlabroot%/toolbox/matlab/codetools/profview.m. This function can be edited in the MATLAB editor via edit(‘profview’)).
The following is from lines 1410-1418 of profview.m in R2012a:

% Display the time
if timePerLine > 0.01,
    s{end+1} = sprintf('<span style="color: #FF0000"> %5.2f </span>',...
        timePerLine);
elseif timePerLine > 0
    s{end+1} = '<span style="color: #FF0000">&lt; 0.01 </span>';
else
    s{end+1} = '       ';
end

which could be replaced by the following (modified lines highlighted):

if timePerLine >= 0.005,    s{end+1} = sprintf('<span style="color: #FF0000"> %6.3f</span>',...        timePerLine);
elseif timePerLine > 0
    s{end+1} = '<span style="color: #FF0000">&lt; 0.005</span>';else
    s{end+1} = '       ';
end