mlpack Timers

Introduction

mlpack provides a simple timer interface for the timing of machine learning methods. The results of any timers used during the program are displayed at output by any command-line binding, when –verbose is given:

$ mlpack_knn -r dataset.csv -n neighbors_out.csv -d distances_out.csv -k 5 -v
<...>
[INFO ] Program timers:
[INFO ]   computing_neighbors: 0.010650s
[INFO ]   loading_data: 0.002567s
[INFO ]   saving_data: 0.001115s
[INFO ]   total_time: 0.149816s
[INFO ]   tree_building: 0.000534s

Timer API

The mlpack::Timer class provides three simple methods:

void Timer::Start(const char* name);
void Timer::Stop(const char* name);
timeval Timer::Get(const char* name);

Each timer is given a name, and is referenced by that name. You can call Timer::Start() and Timer::Stop() multiple times for a particular timer name, and the result will be the sum of the runs of the timer. Note that Timer::Stop() must be called before Timer::Start() is called again, otherwise a std::runtime_error exception will be thrown.

A "total_time" timer is run by default for each mlpack program.

Timer Example

Below is a very simple example of timer usage in code.

#include <mlpack/core.hpp>
#include <mlpack/core/util/io.hpp>
#define BINDING_TYPE BINDING_TYPE_CLI
#include <mlpack/core/util/mlpack_main.hpp>
 
using namespace mlpack;
 
void mlpackMain()
{
  // Start a timer.
  Timer::Start("some_timer");
 
  // Do some things.
  DoSomeStuff();
 
  // Stop the timer.
  Timer::Stop("some_timer");
}

If the –verbose flag was given to this executable, the time that "some_timer" ran for would be printed at the end of the program's output.