The following mathematical functions are provided by PipeDream.
ABS(number)
Returns the absolute positive value of number.
BETA(a,b)
Returns the value of the Beta function for arguments a,b.
One definition of the Beta function is
beta(a, b) = gamma(a) × gamma(b) ÷ gamma(a + b)
This special function is actually evaluated by PipeDream using the formula
beta(a, b) = exp( gammaln(a) + gammaln(b) - gammaln(a + b) )
COMBIN(n,k)
This function yields the number of combinations of n unlike things taken k at a time.
The formula used is:
nCk = n! ÷ ((n - k)! × k!)
For very large n this is an approximation achieved using logarithms.
EXP(number)
Returns the constant e (2.71828184..) raised to the specified power.
FACT(n)
This function yields the factorial of n (most commonly shortened to n!). n must be an integer greater than or equal to zero.
The formula used is:
n! = n × (n - 1) ... × 2 × 1, ie n! = Πi=n i
If the result is too big to fit in an integer it becomes floating point.
For very large n this is an approximation achieved using logarithms.
GAMMALN(number)
This special function yields the natural logarithm of the gamma function of number.
INT(number)
Returns the integer part of number.
LN(number)
Returns the natural logarithm of number. The number must be positive.
LOG(number)
Returns the logarithm to base 10 of number. The number must be positive.
MOD(a,b)
Gives the remainder after division of a by b.
PERMUT(n,k)
This function yields the number of permutations of n unlike things taken k at a time.
The formula used is:
nPk = n! ÷ (n - k)!
For very large n this is an approximation achieved using logarithms.
SGN(number)
Returns -1, 0, or 1 depending on whether number is negative, zero, or positive, non-zero respectively.
SQR(number)
Returns the positive square root of number. The number cannot be less than zero.
SUM(list)
Sum of the values in list.