Re: Save produces large files

[David Bateman]

Mike Miller a écrit :

> On Tue, 14 Jun 2005, David Bateman wrote:
>
> > Søren Hauberg a écrit :
> >
> > > a = zeros(3); a(5) = NaN;
> > > octave:25> save -float-binary test.data a
> > >
> > > which gives me the following warning:
> > >
> > > warning: save: some values too large to save as floats --
> > > warning: save: saving as doubles instead
> > >
> > > Btw. I'm using 2.1.71 on linux
> >
> >
> > That's pretty stupid behaviour... Perhaps the test for whether data 
> > can be saved as float needs to be updated to allow that NaN can be 
> > saved as float.....
>
>
>
> How is NaN encoded?  The "too large to save as floats" seems to imply 
> that NaN is encoded as a large value.  Is that the case?
>
> Mike

No it implies that the > and < operators with NaN on the left-hand side 
always return true... Consider the attached patch (John do I commit it?)

D.


2005-06-14  David Bateman  <address@hidden>

   * dMatrix.cc (too_large_for_float): Special case NaN and NA values
   * CMatrix.cc (too_large_for_float): Ditto

*** liboctave/CMatrix.cc~       2005-04-28 23:42:46.000000000 +0200
--- liboctave/CMatrix.cc        2005-06-14 16:51:07.532501906 +0200
***************
*** 2607,2616 ****
        double r_val = std::real (val);
        double i_val = std::imag (val);
  
!       if (r_val > FLT_MAX
!           || i_val > FLT_MAX
!           || r_val < FLT_MIN
!           || i_val < FLT_MIN)
          return true;
        }
  
--- 2607,2616 ----
        double r_val = std::real (val);
        double i_val = std::imag (val);
  
!       if (((! octave_is_NaN_or_NA (r_val)) && 
!            (r_val > FLT_MAX || r_val < FLT_MIN)) ||
!           ((! octave_is_NaN_or_NA (i_val)) && 
!            (i_val > FLT_MAX || i_val < FLT_MIN)))          
          return true;
        }
  
*** liboctave/dMatrix.cc~       2005-04-26 21:28:16.000000000 +0200
--- liboctave/dMatrix.cc        2005-06-14 16:47:20.121487592 +0200
***************
*** 2114,2120 ****
      {
        double val = elem (i);
  
!       if (val > FLT_MAX || val < FLT_MIN)
        return true;
      }
  
--- 2114,2120 ----
      {
        double val = elem (i);
  
!       if ((! octave_is_NaN_or_NA (val)) && (val > FLT_MAX || val < FLT_MIN))
        return true;
      }