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Diffstat (limited to 'manual/arith.texi')
| -rw-r--r-- | manual/arith.texi | 17 |
1 files changed, 9 insertions, 8 deletions
diff --git a/manual/arith.texi b/manual/arith.texi index 31d638c2a2..d0863f98df 100644 --- a/manual/arith.texi +++ b/manual/arith.texi @@ -41,15 +41,15 @@ these situations. There is a special value for infinity. @comment math.h @comment ISO @deftypevr Macro float_t INFINITY -A expression representing the infinite value. @code{INFINITY} values are -produce by mathematical operations like @code{1.0 / 0.0}. It is +An expression representing the infinite value. @code{INFINITY} values are +produced by mathematical operations like @code{1.0 / 0.0}. It is possible to continue the computations with this value since the basic operations as well as the mathematical library functions are prepared to handle values like this. Beside @code{INFINITY} also the value @code{-INFINITY} is representable and it is handled differently if needed. It is possible to test a -variables for infinite value using a simple comparison but the +value for infiniteness using a simple comparison but the recommended way is to use the the @code{isinf} function. This macro was introduced in the @w{ISO C 9X} standard. @@ -357,7 +357,8 @@ cut along the negative real axis. @deftypefunx {complex long double} cprojl (complex long double @var{z}) Return the projection of the complex value @var{z} on the Riemann sphere. Values with a infinite complex part (even if the real part -is NaN) are projected to positive infinite on the real axis. If the real part is infinite, the result is equivalent to +is NaN) are projected to positive infinite on the real axis. If the +real part is infinite, the result is equivalent to @smallexample INFINITY + I * copysign (0.0, cimag (z)) @@ -1060,13 +1061,13 @@ format supports this; and to the largest representable value otherwise. If the input string is @code{"nan"} or @code{"nan(@var{n-char-sequence})"} the return value of @code{strtod} is the representation of the NaN (not a number) value (if the -floating-point formats supports this. The form with the -@var{n-char-sequence} enables in an implementation specific way to -specify the form of the NaN value. When using the @w{IEEE 754} +floating-point format supports this). In the second form the part +@var{n-char-sequence} allows to specify the form of the NaN value in an +implementation specific way. When using the @w{IEEE 754} floating-point format, the NaN value can have a lot of forms since only at least one bit in the mantissa must be set. In the GNU C library implementation of @code{strtod} the @var{n-char-sequence} is interpreted -as a number (as recognized by @code{strtol}, @pxref{Parsing of Integers}) +as a number (as recognized by @code{strtol}, @pxref{Parsing of Integers}). The mantissa of the return value corresponds to this given number. Since the value zero which is returned in the error case is also a valid |