\\% Expansion in radix r
\\ Author: Joerg Arndt
\\ License: GPL version 3 or later
\\ online at http://www.jjj.de/pari/
\\ version: 2011-January-19 (12:49)



n2rad(n,r)=
{ /* convert n into radix r (as vector) */
    local(len, v);
    if ( n==0, return( [0] ) );
    len = valuation(n,r);
    if ( n == (r^len), return( vector(len+1,n,if(n==1,1,0)) ) );

    len = ceil( log(n)/log(r) );
    v = vector(len);
    forstep (k=len, 1, -1,  v[k] = n%r;  n \= r;  );
    return( v );
} /* ----- */


rad2n(v,r)=
{ /* inverse of n2rad() */
    local(len, t, p);
    t = 0;  p = 1;  len = length(v);
    forstep (k=len, 1, -1,  t += v[k]*p;  p *= r;  );
    return( t );
} /* ----- */


\\ ==== end of file ====