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http://0922267152.blogspot.tw/2011/04/blog-post_13.html

 

Math functions

double pow ( double, double ) - power of

NSLog(@"%.f", pow(3,2) ); //result 9
NSLog(@"%.f", pow(3,3) ); //result 27

double sqrt( double ) - square root

NSLog(@"%.f", sqrt(16) ); //result 4
NSLog(@"%.f", sqrt(81) ); //result 9

double ceil ( double ) - if the argument has any decimal part, returns the next bigger integer

NSLog(@"res: %.f", ceil(3.000000000001)); //result 4
NSLog(@"res: %.f", ceil(3.00)); //result 3

double floor ( double ) - removes the decimal part of the argument

NSLog(@"res: %.f", floor(3.000000000001)); //result 3
NSLog(@"res: %.f", floor(3.9999999)); //result 3

double round ( double ) - rounds the argument

NSLog(@"res: %.f", round(3.5)); //result 4
NSLog(@"res: %.f", round(3.46)); //result 3
NSLog(@"res: %.f", round(-3.5)); //NB: this one returns -4

double fmin ( double, double ) - returns the smaller argument

NSLog(@"res: %.f", fmin(5,10)); //result 5

double fmax ( double, double ) - returns the bigger argument

NSLog(@"res: %.f", fmax(5,10)); //result 10

double fabs( double ) - returns the absolute value of the argument

NSLog(@"res: %.f", fabs(10)); //result 10
NSLog(@"res: %.f", fabs(-10)); //result 10

 

Few math constants

As found in the math.h

#define M_E         2.71828182845904523536028747135266250   /* e */
#define M_LOG2E     1.44269504088896340735992468100189214   /* log 2e */
#define M_LOG10E    0.434294481903251827651128918916605082  /* log 10e */
#define M_LN2       0.693147180559945309417232121458176568  /* log e2 */
#define M_LN10      2.30258509299404568401799145468436421   /* log e10 */
#define M_PI        3.14159265358979323846264338327950288   /* pi */
#define M_PI_2      1.57079632679489661923132169163975144   /* pi/2 */
#define M_PI_4      0.785398163397448309615660845819875721  /* pi/4 */
#define M_1_PI      0.318309886183790671537767526745028724  /* 1/pi */
#define M_2_PI      0.636619772367581343075535053490057448  /* 2/pi */
#define M_2_SQRTPI  1.12837916709551257389615890312154517   /* 2/sqrt(pi) */
#define M_SQRT2     1.41421356237309504880168872420969808   /* sqrt(2) */
#define M_SQRT1_2   0.707106781186547524400844362104849039  /* 1/sqrt(2) */

#define MAXFLOAT ((float)3.40282346638528860e+38)
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