Mathematica 9 is now available
Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
1997
*January
*February
*March
*April
*May
*June
*July
*August
*September
*October
*November
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 1997

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

Search the Archive

Float32 from a file

  • To: mathgroup at smc.vnet.net
  • Subject: [mg5826] Float32 from a file
  • From: rudy at msunews.cl.msu.edu (Rudolf B. Blazek)
  • Date: Thu, 23 Jan 1997 03:19:30 -0500
  • Organization: Michigan State University
  • Sender: owner-wri-mathgroup at wolfram.com

Hi Mma group.

I have to read a binary file with float32 numbers in it. The file was most 
likely created with a C program.

1) I am about to write a Mathematica function that will read 4 bytes at a 
time and compute what the real number was. 

2) I am also considering writing a little C program to read the dataset and 
return the real numbers as ASCII. Then I would call the utility from 
Mathematica. 

Could someone tell me if they've done something like that?

I like the solution 1) for being written completely in Mma. But it will be 
slow.

I like the solution 2) for being fast and using some C built in mechanism for 
writing/reading such files with automatic conversion of the 4 bytes into a 
real number. But one needs to compile the C program for each platform, put it 
into some reasonable place, call it from Mma... :-(((

Questions:

a) Would you know how the conversion of the 4 bytes into the real number 
should look like? I found some reference to a booklet with an ANSI standard 
for the float32 real numbers, but I don't have the booklet.

b) If you wrote a utility similar to what I described. Would you share it?

c) Could you possibly give me a short example how float32 type is read from 
and external file in C, C++, or Objective C ? 

Thank you, a nice day to all.

Rudy

--
Rudy Blazek                        Michigan State University
blazek at stt.msu.edu                 Department of Statistics & Probability



  • Prev by Date: Re: extracting elements from a list of lists
  • Next by Date: Mathematica Courses Amsterdam
  • Previous by thread: Re: extracting elements from a list of lists
  • Next by thread: Mathematica Courses Amsterdam