====== Condition ======
With this element smaller if-clauses can be implemented. It can be verified if the I/O fulfills certain conditions and therefore needs different processing. The condition will not modify the I/O.

===== Usage =====
{{ :eyes:flowcontrol:conditionprop.png?nolink&600|}}
[[https://www.lua.org/manual/5.1/manual.html#2.5.2 | Relational operators from Lua]] are used to construct valid condition statements. All statements formulated with relational operators return true or false. The condition will not modify the I/O. It only passes the IO to either the then - true or else - false output stream.\\

In order to verify a specification of an I/O it is necessary to formulate a conditional statement.
 
To compare a certain I/O header value it is possible to read this value by standard Lua scripting.\\
**cow.io[0]["image header value name"]  == value** \\

Furthermore, [[eyes:flowcontrol:variable|Variables]] can be checked to fulfill certain requirements. A Variable is called with the prefix "cow."\\
**cow.VariableName  > = value**

A third option is to compare a header value of an I/O with a Variable.\\
**cow.VariableName  < = cow.io[0]["image header value name"]** 







===== Example ====
{{ :eyes:flowcontrol:condition.png?nolink800 |}}

**Properties Window**  
|< 100% 5% 40% >|
^                    ^                  ^      ^
|{{:eyes:flowcontrol:a.png?nolink&40|}}|{{:eyes:flowcontrol:conditionproperties.png?nolink|}}|The condition here in the example verifies the dimension of the I/O from the Import logic on the first position of the I/O. It checks whether the header key dimensionality is equal to three. In this case the condition is true and therefore the statement will pass the I/O to the logic Projection. The logic ran through and went green.  The logic FourierProcesses is pending.|

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

|< 100% 30% >|
^ Input   ^ Description ^
| FirstInput  | IO to be passed unmodified |

|< 100% 30% >|
^ Output   ^ Description ^
| FirstOutput | IO passed, if the condition is true |
| SecondOutput | IO passed, if the condition is false  |

===== Concept =====
[[https://www.lua.org/pil/3.2.html|Relational Operators in Lua]]