Databases
StackOverflow2013
Postsdbo
POFSharp runs my algorithm slower than Python
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POFSharp runs my algorithm slower than Python
    primarykey
    data
    text
    <p>Years ago, I solved a problem via dynamic programming:</p> <p><a href="https://www.thanassis.space/fillupDVD.html" rel="noreferrer">https://www.thanassis.space/fillupDVD.html</a></p> <p>The solution was coded in Python.</p> <p>As part of expanding my horizons, I recently started learning OCaml/F#. What better way to test the waters, than by doing a direct port of the imperative code I wrote in Python to F# - and start from there, moving in steps towards a functional programming solution.</p> <p>The results of this first, direct port... are disconcerting:</p> <p>Under Python:</p> <pre><code> bash$ time python fitToSize.py .... real 0m1.482s user 0m1.413s sys 0m0.067s </code></pre> <p>Under FSharp:</p> <pre><code> bash$ time mono ./fitToSize.exe .... real 0m2.235s user 0m2.427s sys 0m0.063s </code></pre> <p>(in case you noticed the "mono" above: I tested under Windows as well, with Visual Studio - same speed).</p> <p>I am... puzzled, to say the least. Python runs code faster than F# ? A compiled binary, using the .NET runtime, runs SLOWER than Python's interpreted code?!?!</p> <p>I know about startup costs of VMs (mono in this case) and how JITs improve things for languages like Python, but still... I expected a speedup, not a slowdown!</p> <p>Have I done something wrong, perhaps?</p> <p>I have uploaded the code here:</p> <p><a href="https://www.thanassis.space/fsharp.slower.than.python.tar.gz" rel="noreferrer">https://www.thanassis.space/fsharp.slower.than.python.tar.gz</a></p> <p>Note that the F# code is more or less a direct, line-by-line translation of the Python code.</p> <p>P.S. There are of course other gains, e.g. the static type safety offered by F# - but if the resulting speed of an imperative algorithm is worse under F# ... I am disappointed, to say the least.</p> <p><strong>EDIT</strong>: Direct access, as requested in the comments:</p> <p>the Python code: <a href="https://gist.github.com/950697" rel="noreferrer">https://gist.github.com/950697</a></p> <p>the FSharp code: <a href="https://gist.github.com/950699" rel="noreferrer">https://gist.github.com/950699</a></p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USttsiodras
    1. USttsiodras
    plurals
    1. PL
      singulars
      1. LTLinked
    1. PL
      singulars
      1. LTLinked
    2. PL
      singulars
      1. LTLinked
    3. PL
      singulars
      1. LTLinked
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    3. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POFSharp runs my algorithm slower than Python
      1. USunutbu
      1. VTFavorite
    2. VO
      singulars
      1. POFSharp runs my algorithm slower than Python
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. POFSharp runs my algorithm slower than Python
      1. This table or related slice is empty.
      1. VTUpMod
    1. COPlease use something like http://gist.github.com/ to upload your code... it really sucks having to download a tar.gz file to see your code
      singulars
      1. POFSharp runs my algorithm slower than Python
      1. USrazenha
    2. COIt's myths, all myths. It's not compiled that is faster, or interpreted that is faster, or native that is faster, or jitted that is faster. Only faster is faster. Live by that.
      singulars
      1. POFSharp runs my algorithm slower than Python
      1. USR. Martinho Fernandes
    3. CO@razenha: The tarball includes a Makefile, with the compilation flags I used. Maybe I missed something there and somebody will point it out - hence the tarball.
      singulars
      1. POFSharp runs my algorithm slower than Python
      1. USttsiodras
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload