Expression: Selector Functions
The following functions are available to map the values from selector variables to strings and numerics. Once mapped they can be used with any functions and operators that support those types.
A selector variable has coded categories like PostArea or Income Band. Each category has a code and a description.
An Income band category might look like this:
|
Code |
Description |
|
00 |
Unclassified |
|
01 |
< 10k |
|
02 |
10-20k |
|
03 |
20-30k |
|
04 |
30-40k |
|
CodeOf
|
Returns the code of the selector variable
CodeOf([Selector Variable])
CodeOf([Income Band]) = "04"
|
|
DescOf
|
Returns the decode description of the selector variable
DescOf([Selector Variable])
DescOf([Income Band]) = “30 – 40k”
|
|
ValueOf
|
Returns the description of the selector variable as a number
ValueOf([Selector Variable])
ValueOf([Income Band]) = 30 as it just takes the first number
|
|
IndexOf
|
Returns the index of the code of the selector variable as a number
IndexOf([Selector Variable])
IndexOf([Income Band]) is 4. Unclassified is zero
|
| InstantCountOf |
Returns the 'instant count' of the selector variable as a number
InstantCountOf([Income]) e.g. £100k+ = 53
In this example 53 people have an income of £100k+
|
| VarSelect |
Returns the index of the given code for the given selector variable if the record in question has one of the code values set
VarSelect([Income], "01", "02", "03")
1 for all records that have an Income value with code "01", 2 for all records that have an Income value with code "02", 3 for all records that have an Income value with code "03" and blank otherwise
|
| Cardinality of |
Returns the number of category codes for selector variables
|
| VarDesc |
Returns the description for a selector variable category:
VarDesc([myVar],"code") returning the description for the corresponding code or VarDesc([myVar],N) returning the description corresponding to index N
VarDesc([myVar],CreateSet(2,3)) - returns a delimited string of descriptions corresponding to the indexes in the set |
| VarSelectCode |
Returns the first matched code based on each selector variable evaluating along the parameters. Multiple sets of selector variable and values lists can be used. For example:
VarSelectCode ([postsect], ”CV34 3”, ”CV34 4”, [postdist], ”CV31” , [postarea], ”B”,”OX”)
Specifying the optional "AsDesc" presents the output as descriptions, if these are available. |
| NthSelectedFlag |
Returns the description of the Nth selected flag in a flag array
If N is negative then the Nth from last is selected |
| NthIndexSelectedFlag |
Returns the index of the Nth selected flag in a flag array
If N is negative then the Nth from last is selected |