librelist archives

Numbers and the like

From:

Paolo Redaelli

Date:

2011-09-23 @ 12:34

I was starting to wrap Eigen library the king of the hill in linear 
algebra (http://eigen.tuxfamily.org/index.php?title=Main_Page yes, 
better than atlas and most of the times on par with Intel proprietary 
library) discovering that we are a little weak on numeric side:

    * COMPLEX is still missing
    * rational numbers are now "buried" under
      FRACTION_WITH_BIG_INTEGER_NUMBER, we may want to give it a status
      almost on par with integers;
    * the semantic of NUMBER is not what most people would expect, i.e.
      I would turn it into an expanded type, holding a reference to its
      actual content, more or less like Ginac (http://www.ginac.de/)
      does with its Ex type.
    * people working for banks needs DECIMAL_[32|64|128] and fixed-point
      arithmetic; see
      http://en.wikipedia.org/wiki/Decimal32_floating-point_format
      http://en.wikipedia.org/wiki/Fixed-point_arithmetic. Perhaps
      wrapping http://en.wikipedia.org/wiki/Libfixmath may be a possibility.