C語(yǔ)言math函數(shù)庫(kù)手冊(cè)范本

1、函數(shù)名稱(chēng):abs函數(shù)原型 :int abs(int x);函數(shù)功能:求整數(shù)x 的絕對(duì)值函數(shù)返回:計(jì)算結(jié)果參數(shù)說(shuō)明:所屬文件:,使用例：#include #include int main()int number=-1234;printf(number: %d absolute value: %d,number,abs(number); return 0;函數(shù)名稱(chēng):fabs函數(shù)原型:double fabs(double x);函數(shù)功能:求x的絕對(duì)值 .函數(shù)返回:計(jì)算結(jié)果參數(shù)說(shuō)明:所屬文件:使用例：#include #include int main()float number=-1234.0;p

2、rintf(number: %f absolute value: %f,number,fabs(number);return 0;函數(shù)名稱(chēng):cabs函數(shù)原型 :double cabs(struct complex znum)函數(shù)功能:求復(fù)數(shù)的絕對(duì)值函數(shù)返回:復(fù)數(shù)的絕對(duì)值參數(shù)說(shuō)明 :zuum 為用結(jié)構(gòu) struct complex 表示的復(fù)數(shù)，定義如下：struct complexdouble m;double n;所屬文件 :#include #include int main() struct complex z;double val;z.x=2.0;z.y=1.0;val=cabs(z);

3、printf(The absolute value of %.2lfi %.2lfj is %.2lf,z.x,z.y,val); return 0;函數(shù)名稱(chēng):ceil函數(shù)原型 :double ceil(double num)函數(shù)功能:得到不小于num的最小整數(shù)函數(shù)返回:用雙精度表示的最小整數(shù)參數(shù)說(shuō)明:num- 實(shí)數(shù)所屬文件:#include #include int main()double number=123.54;double down,up;down=floor(number);up=ceil(number);printf(original number %5.2lf,number)

4、;printf(number rounded down %5.2lf,down);printf(number rounded up %5.2lf,up);return 0;函數(shù)名稱(chēng):sin函數(shù)原型 :double sin(double x);函數(shù)功能:計(jì)算sinx 的值 .正弦函數(shù)函數(shù)返回:計(jì)算結(jié)果參數(shù)說(shuō)明:單位為弧度所屬文件:使用例：#include #include int main()double result,x=0.5;result=sin(x);printf(The sin() of %lf is %lf,x,result);return 0;函數(shù)名稱(chēng):cos函數(shù)原型 :doubl

5、e cos(double x);函數(shù)功能:計(jì)算cos(x) 的值 .余弦函數(shù).函數(shù)返回:計(jì)算結(jié)果參數(shù)說(shuō)明:x 的單位為弧度所屬文件:使用例：#include #include int main()double result;double x=0.5;result=cos(x);printf(The cosine of %lf is %lf,x,result);return 0;函數(shù)名稱(chēng):tan函數(shù)原型 :double tan(double x);函數(shù)功能:計(jì)算tan(x) 的值 ,即計(jì)算角度 x的正切數(shù)值函數(shù)返回:計(jì)算結(jié)果參數(shù)說(shuō)明:x=0單位為弧度所屬文件:使用例：#include #incl

6、ude int main()double result,x;x=0.5;result=tan(x);printf(The tan of %lf is %lf,x,result);函數(shù)名稱(chēng):asin函數(shù)原型:double asin(double x);函數(shù)功能： 計(jì)算sinA-1(x)的值.反正弦值函數(shù)函數(shù)返回:計(jì)算結(jié)果參數(shù)說(shuō)明:x 應(yīng)在 -1到 1 圍 .單位為弧度所屬文件:使用例：#include #include int main()double result;double x=0.5;result=asin(x);printf(The arc sin of %lf is %lf,x,re

7、sult);return 0;函數(shù)名稱(chēng):acos函數(shù)原型 :double acos(double x);函數(shù)功能:計(jì)算cosA-1(x) 的值 ,反余弦函數(shù)函數(shù)返回:計(jì)算結(jié)果參數(shù)說(shuō)明:x 應(yīng)在-1到1圍 .切記單位為弧度所屬文件:使用例：#include #include int main()double result;double x=0.5;result=acos(x);printf(The arc cosine of %lf is %lf,x,result);return 0;函數(shù)名稱(chēng):atan函數(shù)原型:double atan(double x);函數(shù)功能： 計(jì)算tanA-1(x)的值.

8、函數(shù)返回:計(jì)算結(jié)果參數(shù)說(shuō)明:單位為弧度所屬文件:使用例：#include #include int main()double result;double x=0.5;result=atan(x);printf(The arc tangent of %lf is %lf,x,result);return 0;函數(shù)名稱(chēng):atan2函數(shù)原型:double atan2(double x,double y);函數(shù)功能： 計(jì)算tanA-1/(x/y)的值.求x/y的反正切值函數(shù)返回:計(jì)算結(jié)果參數(shù)說(shuō)明:單位為弧度所屬文件:使用例：#include #include int main()double resu

9、lt;double x=90.0,y=45.0;result=atan2(y,x);printf(The arc tangent ratio of %lf is %lf,(y/x),result);return 0;函數(shù)名稱(chēng):sinh函數(shù)原型 :double sinh(double x);函數(shù)功能:計(jì)算x的雙曲正弦函數(shù) sinh(x) 的值.函數(shù)返回:計(jì)算結(jié)果參數(shù)說(shuō)明:單位為弧度所屬文件:使用例：#include #include int main()double result,x=0.5;result=sinh(x);printf(The hyperbolic sin() of %lf is

10、 %lf,x,result);return 0; TOC o 1-5 h z 函數(shù)名稱(chēng):cosh函數(shù)原型:double cosh(double x);函數(shù)功能:計(jì)算x的雙曲余弦 cosh(x) 的值.函數(shù)返回:計(jì)算結(jié)果參數(shù)說(shuō)明:所屬文件:使用例：#include #include int main()double result;double x=0.5;result=cosh(x);printf(The hyperboic cosine of %lf is %lf,x,result);return 0;函數(shù)名稱(chēng):tanh函數(shù)原型 :double tanh(double x);函數(shù)功能:計(jì)算 x

11、的雙曲正切函數(shù) tanh(x) 的值.函數(shù)返回:計(jì)算結(jié)果參數(shù)說(shuō)明:x=0所屬文件:使用例：#include #include int main()double result,x;x=0.5;result=tanh(x);printf(The hyperbolic tangent of %lf is %lf,x,result);函數(shù)名稱(chēng):exp函數(shù)原型:double exp(double x);函數(shù)功能:求 e 的 x 次冪函數(shù)返回:計(jì)算結(jié)果 .冪的值參數(shù)說(shuō)明： x-指數(shù)所屬文件:使用例：#include #include int main()double result;double x=4.0

12、;result=exp(x);printf(e raised to the power of %lf(eA%lf)=%lf,x,x,result);return 0;函數(shù)名稱(chēng):floor函數(shù)原型:double floor(double x);函數(shù)功能:求出不大于x 的最大整數(shù).函數(shù)返回:該整數(shù)的雙精度實(shí)數(shù)參數(shù)說(shuō)明:所屬文件:使用例：#include #include int main()double number=123.54;double down,up;down=floor(number);up=ceil(number);printf(original number %10.2lf,num

13、ber);printf(number rounded down %10.2lf,down);printf(number rounded up %10.2lf,up);return 0; TOC o 1-5 h z 函數(shù)名稱(chēng):fmod函數(shù)原型 :double fmod(double x,double y);函數(shù)功能:求整數(shù)x/y 的余數(shù)函數(shù)返回:返回余數(shù)的雙精度數(shù).x/y 的余數(shù)值.參數(shù)說(shuō)明:所屬文件:使用例：#include #include int main()double x=5.0,y=2.0;double result;result=fmod(x,y);printf(The remai

14、nder of (%lf/%lf) is %lf,x,y,result);return 0;函數(shù)名稱(chēng): frexp函數(shù)原型: double frexp(double val,int *eptr);函數(shù)功能：把雙精度數(shù)val分解為數(shù)字部分(尾數(shù))x和以2為底的指數(shù)n,即val=x*2An,n存放在eptr指向的變量中 .函數(shù)返回:返回?cái)?shù)字部分x,0.5=x 且 x1參數(shù)說(shuō)明:val- 待分解的數(shù)所屬文件:使用例：#include #include int main()double mantissa,number;int exponent;number=8.0;mantissa=frexp(num

15、ber,&exponent);printf(The number %lf is,number);printf(%lf times two to the,mantissa);printf(power of %d,exponent);return 0;函數(shù)名稱(chēng) :log函數(shù)原型 :double log(double x);函數(shù)功能： 求logeX(e指的是以e為底)，即計(jì)算x的自然對(duì)數(shù)(ln X)函數(shù)返回:計(jì)算結(jié)果參數(shù)說(shuō)明:所屬文件:使用例：#include #include int main()double result;double x=8.6872;result=log(x);printf(

16、The natural log of %lf is %lf,x,result);return 0;函數(shù)名稱(chēng):log10函數(shù)原型:double log10(double x);函數(shù)功能:求log10 x(10 指的是以 10 為底 ).計(jì)算 x 的常用對(duì)數(shù)函數(shù)返回:計(jì)算結(jié)果參數(shù)說(shuō)明:所屬文件:使用例：#include #include int main()double result;double x=800.6872;result=log10(x);printf(The common log of %lf is %lf,x,result);return 0;函數(shù)名稱(chēng):modf函數(shù)原型 :doub

17、le modf(double val,double *iptr);函數(shù)功能:把雙精度數(shù)val 分解為整數(shù)部分和小數(shù)部分,把整數(shù)部分存到 iptr 指向的單元函數(shù)返回:val 的小數(shù)部分參數(shù)說(shuō)明:val 待分解的數(shù)所屬文件:使用例：#include #include int main()double fraction,integer;double number=100000.567;fraction=modf(number,&integer);printf(The whole and fractional parts of %lf are %lf and %lf,number,integer,f

18、raction);return 0;函數(shù)名稱(chēng):pow函數(shù)原型:double pow(double x,double y);函數(shù)功能： 計(jì)算以x為底數(shù)的y次募，即計(jì)算xAy的值.函數(shù)返回:計(jì)算結(jié)果參數(shù)說(shuō)明： x-底數(shù)，y-募數(shù)所屬文件:使用例：#include #include int main()double x=2.0,y=3.0;printf(%lf raised to %lf is %lf,x,y,pow(x,y);return 0;函數(shù)名稱(chēng):sqrt函數(shù)原型 :double sqrt(double x);函數(shù)功能:計(jì)算x 的開(kāi)平方 .函數(shù)返回:計(jì)算結(jié)果參數(shù)說(shuō)明:x=0所屬文件:使用例：

19、#include #include int main()double x=4.0,result;result=sqrt(x);printf(The square root of %lf is %lf,x,result);函數(shù)名稱(chēng):hypot函數(shù)原型:double hypot(double x,double y)函數(shù)功能:已知直角三角形兩個(gè)直角邊長(zhǎng)度，求斜邊長(zhǎng)度函數(shù)返回:斜邊長(zhǎng)度參數(shù)說(shuō)明： x,y-直角邊長(zhǎng)度所屬文件:#include #include int main()double result;double x=3.0;double y=4.0;result=hypot(x,y);prin

20、tf(The hypotenuse is: %lf,result);return 0;函數(shù)名稱(chēng):poly函數(shù)原型:double poly(double x,int degree,double coeffs)函數(shù)功能:計(jì)算多項(xiàng)式函數(shù)返回:多項(xiàng)式的計(jì)算結(jié)果參數(shù)說(shuō)明： 計(jì)算 cn*xAn+cn-1xAn-1+.+c1*x+c0所屬文件:#include #include int main()double array=-1.0,5.0,-2.0,1.0;double result;result=poly(2.0,3,array);printf(The polynomial: x*3 - 2.0 x*2

21、 + 5x - 1 at 2.0 is %lf,result); return 0;函數(shù)名稱(chēng) :matherr函數(shù)原型 :int matherr(struct exception *e)函數(shù)功能:數(shù)學(xué)錯(cuò)誤計(jì)算處理程序函數(shù)返回:參數(shù)說(shuō)明:該函數(shù)不能被直接調(diào)用，而是被庫(kù)函數(shù)_matherr()調(diào)用所屬文件:#includeint matherr(struct exception *a)return 1;函數(shù)名稱(chēng):ldexp函數(shù)原型:double ldexp(double x,int exponent)函數(shù)功能 :計(jì)算 x*2 的 exponent 次冪，即 2*pow(2,exponent) 的數(shù)

22、值函數(shù)返回:參數(shù)說(shuō)明:所屬文件:#include #include int main()double value;double x=2;value=ldexp(x,3);printf(The ldexp value is: %lf,value);return 0;intabs(int i)double cabs(struct complex znum)double fabs(double x)long labs(long n)doubleexp(double x)double frexp(double value,int *eptr)double ldexp(double value,int

23、exp);double log(double x)double log10(double x)double pow(double x,double y)double pow10(int p)double sqrt(double x)double acos(double x)double asin(double x)返回整型參數(shù)i 的絕對(duì)值返回復(fù)數(shù) znum 的絕對(duì)值返回雙精度參數(shù)x 的絕對(duì)值返回長(zhǎng)整型參數(shù)n 的絕對(duì)值返回指數(shù)函數(shù)ex 的值返回 value=x*2n 中 x 的值 ,n 存貯在 eptr 中返回 value*2exp 的值返回 logex 的值返回 log10 x 的值返回 xy

24、 的值返回 10p 的值返回+VX的值返回x的反余弦cos-1(x)值,x為弧度 返回x的反正弦sin-1(x)值,x為弧度double atan(double x)double atan2(double y,double x)doublecos(double x)doublesin(double x)doubletan(double x)double cosh(double x)double sinh(double x)double tanh(double x)double hypot(double x,double y)x 和 y 為直角邊的長(zhǎng)度,z2=x2+y2double ceil(d

25、ouble x)double floor(double x)void srand(unsigned seed)int rand()double poly(double x,int n,double c) double modf(double value,double *iptr) double fmod(double x,double y) double frexp(double value,int *eptr) double atof(char *nptr)double atoi(char *nptr)double atol(char *nptr)返回 x 的反正切 tan-1(x) 值 ,

26、x 為弧度返回y/x的反正切tan-1(x)值,y的x為弧度返回 x 的余弦 cos(x) 值 ,x 為弧度返回x的正弦sin(x)值,x為弧度返回x的正切tan(x)值,x為弧度返回x 的雙曲余弦cosh(x) 值 ,x 為弧度返回x 的雙曲正弦sinh(x) 值 ,x 為弧度返回x的雙曲正切tanh(x)值,x為弧度返回直角三角形斜邊的長(zhǎng)度 (z),返回不小于x 的最小整數(shù)返回不大于x 的最大整數(shù)初始化隨機(jī)數(shù)發(fā)生器產(chǎn)生一個(gè)隨機(jī)數(shù)并返回這個(gè)數(shù)從參數(shù)產(chǎn)生一個(gè)多項(xiàng)式將雙精度數(shù)value 分解成尾數(shù)和階返回 x/y 的余數(shù)將雙精度數(shù)value 分成尾數(shù)和階將字符串nptr 轉(zhuǎn)換成浮點(diǎn)數(shù)并返回這個(gè)浮點(diǎn)數(shù)將字符串nptr 轉(zhuǎn)換成整數(shù)并返回這個(gè)整數(shù)將字符串nptr 轉(zhuǎn)換成長(zhǎng)整數(shù)并返回這個(gè)整數(shù)char *ecvt(double value,int ndigit,int *decpt,int *sign)將浮點(diǎn)數(shù)value 轉(zhuǎn)換成字符串并返回該字符串char *fcvt(double value,int ndigit,int *decpt,int *sign)將浮點(diǎn)數(shù)value 轉(zhuǎn)換成字符串并返回該字符串char *gcvt(double v