Function: nfnewprec
Section: number_fields
C-Name: nfnewprec
Prototype: Gp
Help: nfnewprec(nf): transform the number field data nf into new data using
 the current (usually larger) precision.
Doc: transforms the number field $\var{nf}$
 into the corresponding data using current (usually larger) precision. This
 function works as expected if \var{nf} is in fact a \var{bnf} or a \var{bnr}
 (update structure to current precision) but may be quite slow: many
 generators of principal ideals have to be computed; note that in this latter
 case, the \var{bnf} must contain fundamental units.
Variant: See also \fun{GEN}{bnfnewprec}{GEN bnf, long prec} and
 \fun{GEN}{bnrnewprec}{GEN bnr, long prec}.
