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Re: 32-bit Unsigned Integers, Was: Unsigned Integers - How? [message #8199 is a reply to message #8110]

Mon, 10 February 1997 00:00

Peter Berdeklis
Messages: 3
Registered: February 1997

Junior Member

On Sat, 8 Feb 1997, David Fanning wrote:
> Somehow, Peter, I just *knew* you didn't have 16-bit integers! :-)

Hard to believe that's cutting edge on a PC, isn't it? :-}

Thank you for your suggestion. It works perfectly. In return, here's
how to do it for an array.

th = '8f7b91dd'x ; Unsigned this is 2407240157.
; Signed this is -1887727139.

th_arr = replicate(th, 10) ; make an array of 10 of them to test

tb_arr = byte(th_arr, 0, 4, 10) ; map the array to a 4x10 array of bytes
; if the initial array is not 1D just add
; dimensions (up to 6 more)

; make your array of 10 doubles

td_arr = double(tb_arr(0,*)) + double(tb_arr(1,*)*2.^8) $
+ double(tb_arr(2,*)*2.^16) + double(tb_arr(3,*)*2.^24)

Of course, as you said, the byte order is dependent on the endian of the
machine. However, there is no need to check if the unsigned has
overflowed since this will correctly map values that haven't. Of course
if you do want to check, just check if the number is <0. It shouldn't be
if it is unsigned. :)

Thanks again for the help.

---------------
Peter Berdeklis
Dept. of Physics, Univ. of Toronto

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[Message index]

		32-bit Unsigned Integers, Was: Unsigned Integers - How? By: davidf on Sat, 08 February 1997 00:00
		Re: 32-bit Unsigned Integers, Was: Unsigned Integers - How? By: plugge on Thu, 13 February 1997 00:00
		Re: 32-bit Unsigned Integers, Was: Unsigned Integers - How? By: James Tappin on Tue, 11 February 1997 00:00
		Re: 32-bit Unsigned Integers, Was: Unsigned Integers - How? By: James Tappin on Tue, 11 February 1997 00:00
		Re: 32-bit Unsigned Integers, Was: Unsigned Integers - How? By: Peter Berdeklis on Mon, 10 February 1997 00:00

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