Re: BinaryIO
- To: mathgroup at smc.vnet.net
- Subject: [mg57826] Re: BinaryIO
- From: dh <dh at metrohm.ch>
- Date: Thu, 9 Jun 2005 05:18:39 -0400 (EDT)
- References: <d86b4j$dgs$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Hi Marko,
First,
FromDate[{2000, 1, 1, 0, 0, 0}] + i
is an integer and you need the format: Integer64 instead of Real64
Second, "BinaryReadList" used without specifying the numbers of elements
does not always work properly and returns a superfloues last element.
Further, if the file is not close before calling "BinaryReadList"
without numbers of elements, it returns subsequently more elements.
"BinaryReadList" is not properly implemented! Mayby Wolfram takes a not.
Best is always to specify the number of elements in "BinaryReadList".
sincerely, Daniel
Marko Kastens wrote:
> Hi,
>
> I have just updated to Mathematica 5.1.1.0 and trying the new BinaryIO-Commands to
> increase the IO speed. But ... here is something strange:
>
>
> n = 1000000;
> TSout = Table[{FromDate[{2000, 1, 1, 0, 0, 0}] + i, Random[]}, {i, n}];
> BinaryWrite["binTS.dat", TSout, {"Real64", "Real64"}]; // Timing
> TSin = BinaryReadList["binTS.dat", {"Real64", "Real64"}]; // Timing
> TSout == TSin
>
>
> Evaluating these lines with a fresh kernel: everything is ok. Evaluate them a
> second time and TSout==TSin produce a _False_. Restarting the kernel:
> everything is ok.
> Every time I (try to) overwrite the file _binTS.dat_ I got a False. It seems to
> me that the routine is not able to overwrite files.
>
> Hmmm, any suggestions?
>
> marko
>