    ProgressReporter
      Copyright (c)  2014 John Abbott
      GNU Free Documentation License, Version 1.2
%!includeconf: ../aux-txt2tags/config.t2t
      TeXTitle{ProgressReporter}{John Abbott}


== Examples ==[examples]
%----------------------------------------------------------------------
- [ex-ProgressReporter1.C ../../examples/index.html#ex-ProgressReporter1.C]
-

== User documentation ==
%======================================================================
``ProgressReporter`` is a simple utility to help keep track of progress
in a long iterative computation; it prints out a short "progress
report" at roughly the indicated time intervals.

``ProgressReporter`` assumes that successive iterations do not vary wildly
in computational cost.


=== Constructors and pseudo-constructors ===[constructors]
%----------------------------------------------------------------------

- ``ProgressReporter(t)``  -- create a reporter which prints at intervals of roughly ``t`` seconds




=== Operations ===[operations]
%----------------------------------------------------------------------
There is essentially one operation: let ``report`` be a ``ProgressReporter``

- ``report()``  -- print a progress report if enough time has elapsed
- ``report(arg1)``  -- print a progress report (incl. value of ``arg1``) if enough time has elapsed
- ``report(arg1, arg2)``  -- print a progress report (incl. values of ``arg1, arg2``)
    if enough time has elapsed


These calls are designed to be cheap when it is not time to produce a report.



== Maintainer documentation ==
%======================================================================

The only "tricky part" was trying to make reports appear at round values
of the internal counter.  It is a little messy, but not hard.

The mem fns ``operator()`` are inline so that most non-printing calls should
be very cheap.  It seems useful to let the user supply some extra values to
be printed.

``increase125`` increases its arg to next number of the form 10^n, 2*10^n or
5*10^n; ``decrease125`` decreases the arg to the next lowest number of that
form.


Initially I tried to make the printed times close to multiples of the
specified interval, but this led to "surprising" behaviour if some CPU
time had been used before starting the loop --  the first report could
be printed after much less than the chosen interval (and the corresponding
number of iterations would be much smaller than expected).  Now the code
simply says next print time is one interval from the previous print time
(so average print intervals will be slightly longer than desired).



== Bugs, shortcomings and other ideas ==
%======================================================================

Should ``increase125`` and ``decrease125`` be moved to utils?


== Main changes ==
%======================================================================

**2014**
- april (v0.99534): first release


