====== Calculate ======
The Calculate element can arithmetically manipulate [[eyes:flowcontrol:variable|Variables]], whereby the I/O remains unmodified.


===== Usage =====
{{ :eyes:flowcontrol:calcprop.png?nolink|}}
This Flow Control element can apply standard arithmetic (+,-,*,/) onto a Variable. Furthermore, the modulo (%) and exponentiation (^) methods are implemented in Lua 5.1.
To edit the formula fill in the Formula field in the Properties. Please note that Variables are called with cow.VariableName.\\
**  Computation with a constant ** \\
cow.VariableName = cow.VariableName + ( any standard arithmetic symbol )  constant \\
**  Computation with a other Cow Variable ** \\
cow.VariableName = cow.VariableName + ( any standard arithmetic symbol )  cow.VariableName \\

Recall that a calculation of a Variable of type decimal and a Variable of type integer returns a Variable of type decimal. \\
\\
\\

===== Example ====

{{:eyes:flowcontrol:examplecalc.png?nolink&650  |}}

**Properties Window**
|< 100% 2% 40% >|
^                    ^                        ^
|{{:eyes:flowcontrol:a.png?nolink&20|}}|{{:eyes:flowcontrol:boxinteger.png?nolink&600|}}|The [[eyes:flowcontrol:variable|]] factor is passed to the logic [[eyes:logics:boxmanipulation|]]. Factor is used as the coarse factor  for the selected processor Coarse.|
|{{:eyes:flowcontrol:b.png?nolink&20|}}|{{:eyes:flowcontrol:varinteger.png?nolink&600|}}|Here the [[eyes:flowcontrol:variable|]] called factor is of type integer with default value two. To see how to set up and use a [[eyes:flowcontrol:variable|]] follow the link.|
|{{:eyes:flowcontrol:c.png?nolink&20|}}|{{:eyes:flowcontrol:groupcalc.png?nolink&600|}}|After clicking into the grey part of the element [[eyes:flowcontrol:group|]] the properties window displays the current value of the [[eyes:flowcontrol:variable|]] factor.|
|{{:eyes:flowcontrol:d.png?nolink&20|}}|{{:eyes:flowcontrol:examplecalcprop.png?nolink&600|}}|The Calculate element displays the computation. Here the sum of the [[eyes:flowcontrol:variable|]] factor and one is written back to the  [[eyes:flowcontrol:variable|]] factor.|

===== Parameters and I/O =====

|< 100% 30% >|
^ Input   ^ Description ^
| FirstInput  | Input is passed along and triggers Calculate|


|< 100% 30% >|
^ Output   ^ Description ^
| FirstOutput | Output which is unmodified |


===== Concept =====
[[https://www.lua.org/pil/3.1.html|Arithmetic Operators in Lua]]