These functions are to help visualize integer and rational numbers in
a more comprehensible format (as a decimal
argument is optional; its default value is 5.
Nto a (decimal) string.
FloatStr(N, SigFig)convert the number
Ninto a string choosing between "decimal" format and "scientific" format. The default value for
ScientificStr(N, SigFig)convert the number
Ninto a string of the form mantissa times power-of-ten, with
SigFigdigits in the mantissa. Note that trailing zeroes are not removed from the mantissa.
DecimalStr(N, DecPlaces)convert the number
Ninto a decimal string with
DecPlacesdigits after the decimal point. The default value for
Note: for values with large numerator or denominator it is quicker to convert
the value to a
RingElem belonging to a
RingTwinFloat and then print
the result. This approach offers less control over the output, and no
guarantee of correct rounding.
ScientificStr gives the clearest guarantees about the
format used, but also produces the least humanly readable result. It
MantissaAndExponent10 to do the conversion.
FloatStr is supposed to be the best general choice.
It passes its args to
ScientificStr in two situations: if the
number is so large that padding would be needed before the decimal
point; if the number is so small that the
would be shorter (i.e. if the exponent is less than -8).
DecimalStr is Anna's preferred choice. It uses
ToString to convert to decimal.
These functions cannot be applied directly to a machine integer; to call
them you have to convert explicitly into a
The switch-over in
FloatStr to scientific notation for "large"
numbers is not ideal; in C the "g" format chooses the shorter between
float and scientific formats. Is it worth the doing the same here?
Anna says an older version of
DecimalStr would suppress trailing zeroes
if the result is exact (e.g.
DecimalStr(5/4,9) would produce
1.250000000. Is this a good idea?
These fns are too slow if
N is a very large integer (or if numerator
and/or denominator are very large). Converting to an
printing that would bemuch faster (except in delicate rounding cases).
ScientificStr, added new