benchmarking

This is a follow-up to this question where I posted this program: #include <algorithm> #include <cstdlib> #include <cstdio> #include <cstring> #include <ctime> #include <iomanip> #include <iostream> #include <vector> #include <chrono> class Stopwatch { public: typedef std::chrono::high_resolution_clock Clock; //! Constructor starts the stopwatch Stopwatch() : mStart(Clock::now()) { } //! Returns elapsed number of seconds in decimal form. double elapsed() { return 1.0 * (Clock::now() - mStart).count() / Clock::period::den; } Clock::time_point mStart; }; struct test_cast { int operator()(const

In perlfaq5 , there's an answer for How do I count the number of lines in a file? . The current answer suggests a sysread and a tr/\n// . I wanted to try a few other things to see how much faster tr/\n// would be, and also try it against files with different average line lengths. I created a benchmark to try various ways to do it. I'm running this on Mac OS X 10.5.8 and Perl 5.10.1 on a MacBook Air: Shelling out to wc (fastest except for short lines) tr/\n// (next fastest, except for long average line lengths) s/\n//g (usually speedy) while( <$fh> ) { $count++ } (almost always a slow poke,

I am starting to study algorithms and data structures seriously, and interested in learning how to compare the performance of the different ways I can implement A&DTs. For simple tests, I can get the time before/after something runs, run that thing 10^5 times, and average the running times. I can parametrize input by size, or sample random input, and get a list of running times vs. input size. I can output that as a csv file, and feed it into pandas. I am not sure there are no caveats. I am also not sure what to do about measuring space complexity. I am learning to program in C++. Are there

How can I get the number of milliseconds since epoch? Note that I want the actual milliseconds, not seconds multiplied by 1000. I am comparing times for stuff that takes less than a second and need millisecond accuracy. (I have looked at lots of answers and they all seem to have a *1000) I am comparing a time that I get in a POST request to the end time on the server. I just need the two times to be in the same format, whatever that is. I figured unix time would work since Javascript has a function to get that time.time() * 1000 will give you millisecond accuracy if possible. int(time.time() *