Difference between revisions of "Timing computations"
Jump to navigation
Jump to search
DonStewart (talk | contribs) (categeorise) |
DonStewart (talk | contribs) |
||
Line 31: | Line 31: | ||
See also [[Timing out computations]]. |
See also [[Timing out computations]]. |
||
+ | |||
+ | Timing a pure computation: |
||
+ | |||
+ | <haskell> |
||
+ | import Text.Printf |
||
+ | import Control.Exception |
||
+ | import System.CPUTime |
||
+ | import Control.Parallel.Strategies |
||
+ | import Control.Monad |
||
+ | import System.Environment |
||
+ | |||
+ | lim :: Int |
||
+ | lim = 10^6 |
||
+ | |||
+ | time :: (Num t, NFData t) => t -> IO () |
||
+ | time y = do |
||
+ | start <- getCPUTime |
||
+ | replicateM_ lim $ do |
||
+ | x <- evaluate $ 1 + y |
||
+ | rnf x `seq` return () |
||
+ | end <- getCPUTime |
||
+ | let diff = (fromIntegral (end - start)) / (10^12) |
||
+ | printf "Computation time: %0.9f sec\n" (diff :: Double) |
||
+ | printf "Individual time: %0.9f sec\n" (diff / fromIntegral lim :: Double) |
||
+ | return () |
||
+ | |||
+ | main = do |
||
+ | [n] <- getArgs |
||
+ | let y = read n |
||
+ | putStrLn "Starting..." |
||
+ | time (y :: Int) |
||
+ | putStrLn "Done." |
||
+ | </haskell> |
||
[[Category:Code]] |
[[Category:Code]] |
Revision as of 19:13, 27 February 2009
Timing an IO computation.
import Text.Printf
import Control.Exception
import System.CPUTime
time :: IO t -> IO t
time a = do
start <- getCPUTime
v <- a
end <- getCPUTime
let diff = (fromIntegral (end - start)) / (10^12)
printf "Computation time: %0.3f sec\n" (diff :: Double)
return v
main = do
putStrLn "Starting..."
time $ product [1..10000] `seq` return ()
putStrLn "Done."
And running this.
$ runhaskell A.hs
Starting...
Computation time: 1.141 sec
Done.
See also Timing out computations.
Timing a pure computation:
import Text.Printf
import Control.Exception
import System.CPUTime
import Control.Parallel.Strategies
import Control.Monad
import System.Environment
lim :: Int
lim = 10^6
time :: (Num t, NFData t) => t -> IO ()
time y = do
start <- getCPUTime
replicateM_ lim $ do
x <- evaluate $ 1 + y
rnf x `seq` return ()
end <- getCPUTime
let diff = (fromIntegral (end - start)) / (10^12)
printf "Computation time: %0.9f sec\n" (diff :: Double)
printf "Individual time: %0.9f sec\n" (diff / fromIntegral lim :: Double)
return ()
main = do
[n] <- getArgs
let y = read n
putStrLn "Starting..."
time (y :: Int)
putStrLn "Done."