ilogb

 

C

Lingua

Tipo di supporto

Gestione della memoria dinamica

La gestione degli errori

Programma di utilità

Data e ora utilità

Stringhe libreria

Algoritmi

Numeri

Ingresso / uscita supporto

Localizzazione supporto

Thread di supporto(C11)

Operazioni atomiche(C11)

 

Numeri

Comuni funzioni matematiche

Virgola mobile ambiente

Complex number arithmetics

Generazione di numeri casuali

Tipo-generic matematica

 

Comuni funzioni matematiche

Funzioni Original: Functions The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
Operazioni di base Original: Basic operations The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
abs labs llabs imaxabs (C99) fabs div ldiv lldiv imaxdiv (C99) fmod	remainder (C99) remquo (C99) fma (C99) fmax (C99) fmin (C99) fdim (C99) nan nanf nanl (C99) (C99) (C99)
Funzioni esponenziali Original: Exponential functions The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
exp exp2 (C99) expm1 (C99)	log log10 log1p (C99) log2 (C99)
Funzioni di risparmio energia Original: Power functions The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
sqrt cbrt (C99)	hypot (C99) pow
Funzioni trigonometriche e iperboliche Original: Trigonometric and hyperbolic functions The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
sin cos tan asin acos atan atan2	sinh cosh tanh asinh (C99) acosh (C99) atanh (C99)
Errore e gamma funzioni Original: Error and gamma functions The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
erf (C99) erfc (C99)	lgamma (C99) tgamma (C99)
Più vicini operazioni di interi in virgola mobile Original: Nearest integer floating point operations The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
ceil floor round lround llround (C99) (C99) (C99)	trunc (C99) nearbyint (C99) rint lrint llrint (C99) (C99) (C99)
Floating funzioni di manipolazione di punti Original: Floating point manipulation functions The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
ldexp scalbn scalbln (C99) (C99) ilogb (C99) logb (C99)	frexp modf nextafter nexttoward (C99) (C99) copysign (C99)
Classificazione Original: Classification The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
fpclassify (C99)
isfinite (C99)
isinf (C99)
isnan (C99)
isnormal (C99)
signbit (C99)
Macro costanti Original: Macro constants The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
HUGE_VALF HUGE_VAL HUGE_VALL (C99) (C99)	FP_NORMAL FP_SUBNORMAL FP_ZERO FP_INFINITE FP_NAN (C99) (C99) (C99) (C99) (C99)

 

Elemento definito nell'header <math.h>
int ilogbf(float arg );
int ilogb(double arg );
int ilogbl(longdouble arg );
#define FP_ILOGB0 /*implementation-defined*/
#define FP_ILOGBNAN /*implementation-defined*/

Estrae il valore dell'esponente dal virgola mobile arg argomento, e restituisce come valore intero con segno. Formalmente, il risultato è la parte integrale di log
r|arg| come valore integrale con segno, per i non-zero arg, dove r è FLT_RADIX.

Original:

Extracts the value of the exponent from the floating-point argument arg, and returns it as a signed integer value. Formally, the result is the integral part of log
r|arg| as a signed integral value, for non-zero arg, where r is FLT_RADIX.

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Parametri

arg

-

valore in virgola mobile Original: floating point value The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

Valore di ritorno

La virgola mobile esponente, il cast a intero.

Original:

The floating-point exponent, cast to integer.

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Errore di dominio o l'intervallo si può verificare se arg è pari a zero, FP_ILOGB0 viene restituito in questo caso.

Original:

Domain or range error may occur if arg is zero, FP_ILOGB0 is returned in that case.

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Errore di dominio o l'intervallo si può verificare se arg è infinito, MAX_INT viene restituito in questo caso.

Original:

Domain or range error may occur if arg is infinite, MAX_INT is returned in that case.

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Errore di dominio o l'intervallo si può verificare se arg è NaN, FP_ILOGBNAN viene restituito in questo caso.

Original:

Domain or range error may occur if arg is NaN, FP_ILOGBNAN is returned in that case.

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Se il risultato non può essere rappresentato come int, il risultato è indefinito.

Original:

If the result cannot be represented as int, the result is undefined.

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Note

Il valore dell'esponente restituito da ilogb è sempre inferiore a 1 l'esponente rientrati da frexp causa dei diversi requisiti di normalizzazione: per l'esponente e restituito da ilogb, |arg*r-e
| è tra 1 e r (tipicamente tra 1 e 2), ma per l' esponente e restituito da frexp, |arg*2-e
| è tra 0.5 e 1.

Original:

The value of the exponent returned by ilogb is always 1 less than the exponent retuned by frexp because of the different normalization requirements: for the exponent e returned by ilogb, |arg*r-e
| is between 1 and r (typically between 1 and 2), but for the exponent e returned by frexp, |arg*2-e
| is between 0.5 and 1.

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Vedi anche

frexp	scompone un numero in significante e una potenza di 2 Original: decomposes a number into significand and a power of 2 The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (funzione)
logb (C99)	estrae esponente del numero Original: extracts exponent of the number The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (funzione)
scalbn scalbln (C99) (C99)	moltiplica un numero per FLT_RADIX elevato a una potenza Original: multiplies a number by FLT_RADIX raised to a power The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (funzione)
C++ documentation for ilogb