User-defined Function


Menu location: Data_Transforming and Deriving_User-defined Function.


This applies an algebraic expression to any selection of data. The workbook column(s) you select are given the variable names X1, X2 ... Xn in the order that they are selected from left to right across the workbook. You can then create a new column as a function of those selected. You do this by entering an algebraic expression that can use any of the functions, operators and constants below. For example X1/SQR(X2) would produce a column where each row entry was that of the first selected column divided by the square root of the corresponding row entry in the second selected column.


The same results can be achieved using intrinsic functions within a StatsDirect workbook. Large complex functions may be handled faster by the intrinsic workbook functions of StatsDirect.


PI 3.14159265358979323846 (p)
EE 2.71828182845904523536 (e)
Arithmetic Functions  
ABS absolute value
CLOG common (base 10) logarithm
CEXP anti log (base 10)
EXP anti log (base e)
LOG natural (base e, Naperian) logarithm
LOGIT logit: log(p/[1-p]), p=proportion
ALOGIT antilogit: exp(l)/[1+exp(l)], l=logit
SQR or SQRT square root
! factorial (maximum 170.569)
LOG! log factorial
IZ normal deviate for a p value
UZ upper tail p for a normal deviate
LZ lower tail p for a normal deviate
TRUNC or FIX integer part of a real number
CINT real number rounded to nearest integer
INT real number truncated to integer closest to zero


Please note that the largest factorial allowed is 170.569398315538748, but you can work with Log factorials via the LOG! function, e.g. LOG!(171).


Arithmetic Operators  
^ exponentiation (to the power of)
+ addition
- subtraction
* multiplication
/ division
\ integer division


Calculations give an order of priority to arithmetic operators; this must be considered when entering expressions. For example, the result of the expression "6 - 3/2" is 4.5 and not 1.5 because division takes priority over subtraction.


Priority of arithmetic operators in descending order

  1. Exponentiation (^ or **)
  2. Negation (-X) (Exception = x^-y; i.e. 4^-2 is 0.0625 and not -16)
  3. Multiplication and Division (*, /)
  4. Integer Division (\)
  5. Addition and Subtraction (+, -)


Trigonometric Functions  
ARCCOS arc cosine
ARCCOSH arc hyperbolic cosine
ARCCOT arc cotangent
ARCCOTH arc hyperbolic cotangent
ARCCSC arc cosecant
ARCCSCH arc hyperbolic cosecant
ARCTANH arc hyperbolic tangent
ARCSEC arc secant
ARCSECH arc hyperbolic secant
ARCSIN arc sine
ARCSINH arc hyperbolic sine
ATN arc tangent
COS cosine
COT cotangent
COTH hyperbolic cotangent
CSC cosecant
CSCH hyperbolic cosecant
SIN sine
SINH hyperbolic sine
SECH hyperbolic secant
SEC secant
TAN tangent
TANH hyperbolic tangent


To convert degrees to radians, multiply degrees by pi/180. To convert radians to degrees, multiply radians by 180/pi.


Logical Functions  
AND logical AND
NOT logical NOT
OR logical OR
< less than
= equal to
> greater than
<> (also ><) not equal to
>= (also =>) greater than or equal to
<= (also =<) less than or equal to
true expression outcome is true
false expression outcome is false