Developing Apama Applications > Dashboard Function Reference > Scalar Functions > Evaluate Expression As Double
Evaluate Expression As Double
Returns the result of evaluating a specified expression that contains variables, each of which has an associated function argument. The result is returned as a double. Boolean true or false values are returned as 1.0 and 0.0 respectively.
Arguments
The function has the following arguments:
*Expression: Text string that specifies the expression to evaluate. Prefix variable names with%. Use standard arithmetic and logical operators. You can also use a variety of mathematical and string functions, as well as numeric and string constants. Enclose string constants in double quotes.
*Expression variable arguments: When the Expression field of the Edit Function dialog is activated (by pressing Enter or navigating to another field), the dialog displays a text field for each variable. For each field, enter a numeric value or text string. Values whose form is numeric are substituted into the expression as numbers; otherwise they are substituted into the expression as strings.
If a value whose form is numeric needs to be treated as a string, for example to serve as an argument to a string function, surround the variable in Expression with double quotes. Variables enclosed in double quotes are always used as strings. An example of such an expression is length("%var1") + %var2.
This function returns a numerical value.
Copyright © 2013 Software AG, Darmstadt, Germany and/or Software AG USA Inc., Reston, VA, USA, and/or Terracotta Inc., San Francisco, CA, USA, and/or Software AG (Canada) Inc., Cambridge, Ontario, Canada, and/or, Software AG (UK) Ltd., Derby, United Kingdom, and/or Software A.G. (Israel) Ltd., Or-Yehuda, Israel and/or their licensors.