|
|
Sponsored Content
Top Forums
UNIX for Advanced & Expert Users
byte swapping 32-bit float and weird od results
Post 302317361 by GoDonkeys on Monday 18th of May 2009 08:57:09 PM
05-18-2009
byte swapping 32-bit float and weird od results
I'm attempting to read a file that is composed of complex 32-bit floating point values on Solaris 10 that came from a 64-bit Red Hat computer.
When I first tried reading the file, it looked like there was a byte-swapping problem and after running the od command on the file Solaris and Red Hat computers, I saw that they were indeed swapped (every other byte). So, I wrote a little Java program that would swap every other byte and the result was the at the byte-level, the files were the same on both computers. The following is the result of running 'od -x' on the file, showing the first 32-bits which represent the real portion of the first complex number:
f8a6 be03 cd76 bc99
What's weird is that when I run 'od -f' on both computers to see the 32-bit floating point value, I get different results! On the Red Hat computer I get: -1.288782e-01 and on the Solaris computer I get: -2.7055474e+34
. How can I have the same byte level file yet come up with completely different values when I try to print out the bytes as 32-bit floats?
This is really messing me up trying to write a C++ program to read this file on the Solaris computer. I'm getting the same value in my C++ code as what I see when I run 'od -f' on the Solaris computer. I've tried just about everything that I can think of and haven't been able to get past this.
Does anyone have any idea on what's going on with the od command between the Red Hat and Solaris computers? Any ideas on how to get my C++ code to give me the correct value for the 32-bit float?
When I first tried reading the file, it looked like there was a byte-swapping problem and after running the od command on the file Solaris and Red Hat computers, I saw that they were indeed swapped (every other byte). So, I wrote a little Java program that would swap every other byte and the result was the at the byte-level, the files were the same on both computers. The following is the result of running 'od -x' on the file, showing the first 32-bits which represent the real portion of the first complex number:
f8a6 be03 cd76 bc99
What's weird is that when I run 'od -f' on both computers to see the 32-bit floating point value, I get different results! On the Red Hat computer I get: -1.288782e-01 and on the Solaris computer I get: -2.7055474e+34
. How can I have the same byte level file yet come up with completely different values when I try to print out the bytes as 32-bit floats?This is really messing me up trying to write a C++ program to read this file on the Solaris computer. I'm getting the same value in my C++ code as what I see when I run 'od -f' on the Solaris computer. I've tried just about everything that I can think of and haven't been able to get past this.
Does anyone have any idea on what's going on with the od command between the Red Hat and Solaris computers? Any ideas on how to get my C++ code to give me the correct value for the 32-bit float?
|
|
8 More Discussions You Might Find Interesting
1. Programming
Good morning,
I'm testing the use of ceilf:
/*Filename: str.c*/
#include <stdio.h>
#include <math.h>
int main (void)
{
float ceilf(float x);
int dev=3, result=0;
float tmp = 3.444f;
printf("Result: %f\n",ceilf(tmp));
return 0;
} (1 Reply)
Discussion started by: jonas.gabriel
1 Replies
2. Shell Programming and Scripting
In my server migration requirement, I need to compare if one file on old server is exactly the same as the corresponding file on the new server.
For diff and comm, the inputs need to be sorted. But I do not want to disturb the content of the file and need to find byte-to-byte match.
Please... (4 Replies)
Discussion started by: krishmaths
4 Replies
3. Shell Programming and Scripting
Hi All
Can anyone please suggest me how to remove the last byte from a falt file .This is from the last line's last BYTE.
Please suggest me something.
Thank's and regards
Vinay (1 Reply)
Discussion started by: vinayrao
1 Replies
4. Programming
I was running some timings in my code to see which of several functions was the best and I've been getting some odd results. Here's the code I'm using:
static double time_loop(int (*foo)(int)) {
clock_t start, end;
int n = 0, i = 0;
start = clock();
for (; i <= MAXN; i++)
if... (6 Replies)
Discussion started by: CRGreathouse
6 Replies
5. UNIX for Dummies Questions & Answers
I have a varchar column which contains the data at ‘bit' level.the data needs to be extract / transform at bit level and this will contain a Boolean value - 0/1. How can we handle using shell scripts
At source level(DB2 Database) we have a column of length 250 char ie varchar(250) so each char... (2 Replies)
Discussion started by: Codesearcher
2 Replies
6. Shell Programming and Scripting
Hi guys,
I'm new here. I have a problem at work. One of our scripts was eventually having a bug and only detected recently. Here's the issue and background:
Bash Script which calls AWK script
Awk script returns a string as per below (example):var1='00000-123'So, when we convert it, the... (18 Replies)
Discussion started by: sekfarok
18 Replies
7. UNIX for Beginners Questions & Answers
Hello and thanks in advance for any help anyone can offer me
I'm trying to learn the find command and thought I was understanding it... Apparently I was wrong. I was doing compound searches and I started getting weird results with the -size test. I was trying to do a search on a 1G file owned by... (14 Replies)
Discussion started by: bodisha
14 Replies
8. Windows & DOS: Issues & Discussions
Hello everyone.
I bought a dell laptop (XPS M1330) online which came without a hard drive. There is a Windows Vista Ultimate OEMAct sticker with product key at the bottom case. I checked dell website (here) for this model and it says this model supports both 32 and 64-bit version of Windows... (4 Replies)
Discussion started by: milhan
4 Replies
LEARN ABOUT HPUX
encodedecimal32
_encodedecimal64(3M) _encodedecimal64(3M) NAME
_encodedecimal64(), _encodedecimal128(), _encodedecimal32() - encode decimal-encoded decimal data SYNOPSIS
DESCRIPTION
There are two standard bit-encodings for decimal floating-point data: binary and decimal. Both encoding provide exactly the same data (analogous to big endian and little endian encodings). The HP-UX decimal floating-point types use the binary encoding. The function encodes x as a decimal-encoded 64-bit decimal datum. is a version of it takes a argument and returns a result. is a version of it takes a argument and returns a result. These math functions are supported for HP-UX 11i Version 3 September 2008 Update and forward. USAGE
To use any of these functions, compile with the option. Make sure your program defines and then includes Link in the math library by specifying or on the linking command line. For more information, see the at the following site: RETURN VALUE
returns x in the decimal encoding. raises no exceptions. ERRORS
No errors are defined. SEE ALSO
_decodebinary64(3M), _decodedecimal64(3M), _encodebinary64(3M), math(5). STANDARDS CONFORMANCE
These functions are not specified in any standard. HP Integrity Server Only _encodedecimal64(3M)