例如: 1.2345 -> 1.235
function cRound( value, decplaces )
{
exponential = exp( log( 10 ) * decplaces );
rounded = int( value * exponential + 0.5 ) / exponential;
return rounded;
}
function cPrec( value, decplaces )
{
return Prec( value + 5*10^-(decplaces+1), decplaces );
}
printf( "round1: %g", cRound( 1.2345, 3 ) );
printf( "\nround2: %g", cPrec( 1.2345, 3 ) );
function cPrec( value, decplaces )
{
return Prec( value + 5*10^-(decplaces+1), decplaces );
} |