Version 5.0 The LEDA User Manual

ounding modes bigfloat :: get rounding mode( )
returns the currently active global rounding mode
output modes bigfloat :: set output mode(output modes o mode)
sets the output mode to o mode and returns the old
output mode
A bigfloat x can be rounded by the call round(x, prec, mode, is exact). The optional
boolean variable is exact is set to true if and only if the rounding operation did not
change the value of x.
integer to integer(rounding modes rmode = TO NEAREST ,
bool& is exact = bigfloat :: dbool)
returns the integer value next to x (in the given rounding
mode)
integer to integer(const bigfloat& x, rounding modes rmode = TO NEAREST ,
bool& is exact = bigfloat :: dbool)
returns x.to integer(...).
3. Operations
The arithmetical operators +, −, ∗, /, +=, −=, ∗=, /=, sqrt, the comparison operators
, ≥ , =, ≠ and the stream operators are available. Addition, subtraction, multiplication,
division, square root and power are implemented by the functions add, sub,
mul, div, sqrt and power respectively. For example, the call
add(x, y, prec, mode, is exact)
computes the sum of bigfloats x and y with prec binary digits, in rounding mode mode,
and returns it. The optional last parameter is exact is a boolean variable that is set
to true if and only if the returned bigfloat exactly equals the sum of x and y. The
parameters prec and mode are also optional and have the global default values global prec
and round mode respectively, that is, the three calls add(x, y, global prec, round mode),
add(x, y, global prec), and add(x, y) are all equivalent. The syntax for functions sub,
mul, div, and sqrt is analogous.
The operators +, −, ∗, and / are implemented by their counterparts among the functions
add, sub, mul and div. For example, the call x + y is equivalent to add(x, y).
bool isNaN(const bigfloat& x)
bool isnInf(const bigfloat& x)
returns true if and only if x is in special state NaN
returns true if and only if x is in special state nInf