Re: How to byte swap an IEEE Float?


On 28 Jun 2005, at 21:43, Björn wrote:

Sure. You know, I meant representation = bits and bytes, implying same
length. It seems the OP already has the float type (IEEE_Float_32),
32-bit = 4-byte long, and the data are floats of this length, only
different in byte order.

OP, if the data are of a different length, then you have to unchecked
convert first to a float type of that length, and then normal convert
to the final type (risking Constraint_Error).


All the data in the file are of 32 bits float so that should be ok.
The target for the values is at the moment x86 (although I do expect it
to work on PowerPC as well so I check System.Default_Bit_Order before
doing any byte swapping). My dirty workaround for the moment was to
read the data as a string. I was merly wondering which is the
normal/"best" way to deal with this, since I expect it to be a
fairly common task. A packed byte array does however seem like a much
better idea than handling it as a string.

It is better. Because it's portable. Probably you got away with a String because on your system a String happens to be a packed array of bytes, but this is not guaranteed for all systems by the standard.

.

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