Navigation:  Technical notes > User defined functions

Some SCOUT objects use a formula interpreter to create data. To do this the user usually specifies in a dialog the formula by editing a string. Also the range over which the data will be calculated can be set. When you leave the dialog a formula interpreter checks the formula string and fills the data of the object with new values calculated according to the formula.

 

In a formula string you can use the following functions:

 

Function        Explanation        

 

abs(...)                the absolute value of the argument        

 

sin(...)

cos(...)

tan(...)                trigonometric functions (argument in rad)

cot(...)                                

 

asin(...)

acos(...)        inverse trigonometric functions

atan(...)                

 

sinh(...)

cosh(...)        hyperbolic functions

tanh(...)                

 

exp(...)                the exponential        

ln(...)                the natural logarithm        

log(...)                the logarithm with base 10        

sqr(...)                the square of the argument        

sqrt(...)                the square root of the argument        

frac(...)                returns the fractional part of the argument        

int(...)                  returns the integer part of the argument        

step(...)        the step or 'heavyside' function        

rect(...)                the rect function        

rnd(...)                returns random numbers centered around 0 with amplitude

         given by the argument        

si(...)                sin(...)/(...)        

pi                3.14159        

 

Expressions of the form number1^number2 are allowed and return the number2'th power of number1. Of course the usual operators +,-,*,/ and () can be used to combine expressions.

The variables that can be used in a formula string vary from object to object and are given in the individual formula dialogs.