Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
1998
*January
*February
*March
*April
*May
*June
*July
*August
*September
*October
*November
*December
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 1998

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re:Speed of writing in Mathematica 3.01




In article <6fd5ag$6aq@smc.vnet.net>, bridges@en.com (James Bridges)
wrote:

> Am I doing something wrong or is it supposed to take orders of magnitude
> longer than is reasonable to write out a simple ASCII file from
> Mathematica? Consider this simple test:
>
> In[7]:=
> a=Table [i,{i,1,1001}];
>
> In[8]:=
> Timing[
> filename="Macintosh HD:test.ascii";
> output=OpenWrite[filename];
> Do[
>       Write[output,a[[i]]];
> ,{i,1,1001}];
> Close[output];
>    ]
>
> Out[8]=
> {23.4 Second,Null}
>
> 23 seconds to write 1001 integers?!  On a 233MHz G3! Everything else is
> whiff-bam fast, but writing is glacial. Now this is a simplified
> example of what I need to do but it contains one of the factors, namely
> that I have to individually write out elements of a list, hence the Do
> loop. Any hints?
> > James Bridges
>

Here is one fast way do this sort of thing:

In[3]:=
fast=OpenWrite["test"]
Out[3]=
OutputStream["test",8]
In[4]:=
Write[fast,Table[n,{n,1,1000}]]//Timing Out[4]=
{0.0833333 Second,Null}
In[5]:=
Close[fast]
Out[5]=
"test"
(PowerMac G3 266 MHz)

Andrzej Kozlowski




  • Prev by Date: How can I run Mathematica 2.1E on a PowerMac?
  • Next by Date: Re: WEIBULL DISTRIBUTION
  • Prev by thread: Speed of writing in Mathematica 3.01
  • Next by thread: Re:Speed of writing in Mathematica 3.01