Numerical Methods

Detailed Description

Macros
#define	SCIPisFinite(x)   ((x) == (x))

Functions
SCIP_Real	SCIPcalcMachineEpsilon (void)
SCIP_Longint	SCIPcalcGreComDiv (SCIP_Longint val1, SCIP_Longint val2)
SCIP_Longint	SCIPcalcSmaComMul (SCIP_Longint val1, SCIP_Longint val2)
SCIP_Bool	SCIPrealToRational (SCIP_Real val, SCIP_Real mindelta, SCIP_Real maxdelta, SCIP_Longint maxdnom, SCIP_Longint *nominator, SCIP_Longint *denominator)
SCIP_RETCODE	SCIPcalcIntegralScalar (SCIP_Real *vals, int nvals, SCIP_Real mindelta, SCIP_Real maxdelta, SCIP_Longint maxdnom, SCIP_Real maxscale, SCIP_Real *intscalar, SCIP_Bool *success)
SCIP_Bool	SCIPfindSimpleRational (SCIP_Real lb, SCIP_Real ub, SCIP_Longint maxdnom, SCIP_Longint *nominator, SCIP_Longint *denominator)
SCIP_Real	SCIPselectSimpleValue (SCIP_Real lb, SCIP_Real ub, SCIP_Longint maxdnom)
SCIP_Real	SCIPrelDiff (SCIP_Real val1, SCIP_Real val2)

Macro Definition Documentation

#define SCIPisFinite

(

x

)

((x) == (x))

Definition at line 5428 of file pub_misc.h.

Function Documentation

SCIP_Real SCIPcalcMachineEpsilon

(

void

)

returns the machine epsilon: the smallest number eps > 0, for which 1.0 + eps > 1.0

SCIP_Longint SCIPcalcGreComDiv	(	SCIP_Longint	val1,
		SCIP_Longint	val2
	)

calculates the greatest common divisor of the two given values

Parameters

val1	first value of greatest common devisor calculation
val2	second value of greatest common devisor calculation

SCIP_Longint SCIPcalcSmaComMul	(	SCIP_Longint	val1,
		SCIP_Longint	val2
	)

calculates the smallest common multiple of the two given values

Parameters

val1	first value of smallest common multiple calculation
val2	second value of smallest common multiple calculation

SCIP_Bool SCIPrealToRational	(	SCIP_Real	val,
		SCIP_Real	mindelta,
		SCIP_Real	maxdelta,
		SCIP_Longint	maxdnom,
		SCIP_Longint *	nominator,
		SCIP_Longint *	denominator
	)

converts a real number into a (approximate) rational representation, and returns TRUE iff the conversion was successful

Parameters

val	real value r to convert into rational number
mindelta	minimal allowed difference r - q of real r and rational q = n/d
maxdelta	maximal allowed difference r - q of real r and rational q = n/d
maxdnom	maximal denominator allowed
nominator	pointer to store the nominator n of the rational number
denominator	pointer to store the denominator d of the rational number

SCIP_RETCODE SCIPcalcIntegralScalar	(	SCIP_Real *	vals,
		int	nvals,
		SCIP_Real	mindelta,
		SCIP_Real	maxdelta,
		SCIP_Longint	maxdnom,
		SCIP_Real	maxscale,
		SCIP_Real *	intscalar,
		SCIP_Bool *	success
	)

tries to find a value, such that all given values, if scaled with this value become integral in relative allowed difference in between mindelta and maxdelta

Parameters

vals	values to scale
nvals	number of values to scale
mindelta	minimal relative allowed difference of scaled coefficient s*c and integral i
maxdelta	maximal relative allowed difference of scaled coefficient s*c and integral i
maxdnom	maximal denominator allowed in rational numbers
maxscale	maximal allowed scalar
intscalar	pointer to store scalar that would make the coefficients integral, or NULL
success	stores whether returned value is valid

SCIP_Bool SCIPfindSimpleRational	(	SCIP_Real	lb,
		SCIP_Real	ub,
		SCIP_Longint	maxdnom,
		SCIP_Longint *	nominator,
		SCIP_Longint *	denominator
	)

given a (usually very small) interval, tries to find a rational number with simple denominator (i.e. a small number, probably multiplied with powers of 10) out of this interval; returns TRUE iff a valid rational number inside the interval was found

Parameters

lb	lower bound of the interval
ub	upper bound of the interval
maxdnom	maximal denominator allowed for resulting rational number
nominator	pointer to store the nominator n of the rational number
denominator	pointer to store the denominator d of the rational number

SCIP_Real SCIPselectSimpleValue	(	SCIP_Real	lb,
		SCIP_Real	ub,
		SCIP_Longint	maxdnom
	)

given a (usually very small) interval, selects a value inside this interval; it is tried to select a rational number with simple denominator (i.e. a small number, probably multiplied with powers of 10); if no valid rational number inside the interval was found, selects the central value of the interval

Parameters

lb	lower bound of the interval
ub	upper bound of the interval
maxdnom	maximal denominator allowed for resulting rational number

SCIP_Real SCIPrelDiff	(	SCIP_Real	val1,
		SCIP_Real	val2
	)

returns the relative difference: (val1-val2)/max(|val1|,|val2|,1.0)

Parameters

val1	first value to be compared
val2	second value to be compared