Measure time of execution in F#

Question

Please post code for displaying time in F#. I noticed that you can measure it from F# interactive with #time directive, but I don't know how to execute program from FSI

Thanks

Answer 1

I would just use the .NET Stopwatch class.

let stopWatch = System.Diagnostics.Stopwatch.StartNew() ... stopWatch.Stop() printfn "%f" stopWatch.Elapsed.TotalMilliseconds 

Answer 2

From msdn:

By itself, #time toggles whether to display performance information. When it is enabled, F# Interactive measures real time, CPU time, and garbage collection information for each section of code that is interpreted and executed.

So to test you function you have to open F# interactive console and execute your function in it (one way to do it is to select your function, right click and chose Execute in Interactive) Then make a call to your function in Interactive like that for example:

// define your function first either in interactive console or in your document:

let square x = x * x  // in interactive #time square 10 #time 

You will see how much of real time and CPU time were spent on computation and a bit of information from garbage collector