Re: fread and ubit1

[Jaroslav Hajek]

On Tue, Sep 14, 2010 at 11:56 PM, drumaliens <address@hidden> wrote:
>
> In MATLAB I can read in just 1 bit from a binary file using bit1. In octave I
> can't.
>
> The only way I can think of get round this is to read in an int8, say, see
> if it is greater than 127 which will give a 1 for the MSB and then make use
> of fseek to move back by 7 bits. (Must admit haven't tried this)
>
> Is there any more elegent way of doing this ?
>
> Thanks
>


AFAIK, the smallest unit of binary reading supported by all OSes I
know is a byte. To get bits, just read bytes and decompose them to
bits. In Octave 3.3.52+, this can be conveniently done by bitunpack:

octave:1> bitunpack (uint8(129))
ans =

   1   0   0   0   0   0   0   1

bitpack can be used to pack the logical array back into bytes/words/dwords.

hth

-- 
RNDr. Jaroslav Hajek, PhD
computing expert & GNU Octave developer
Aeronautical Research and Test Institute (VZLU)
Prague, Czech Republic
url: www.highegg.matfyz.cz