SkipNoData

Use this function in a model document to skip intersections containing no data. This function enhances performance by speeding up the parsing of large data areas containing a small amount of data.

If the Collect Statistics command is run prior to this function, the collected statistics are used to maximize SkipNoData function performance.

Caution:

This function is not safe to use on LEAD/ LAG calculations. This function is also not safe to use when there are calculations where the right-hand side of the equation includes any term (elements separated by plus or minus) that resolve to a constant or string literal.

For example:

1. In the case below, the calculations for both A and C have terms on the right-hand side that are constants. It is not safe to use SkipNoData in this scenario:

   A = 2

   C = B + 10

2. In the case below, the calculation for A has a term on the right-hand side that effectively resolves to a constant (VALUE). It is not safe to use SkipNoData in this scenario:

   A = B + VALUE(…)

3. In the case below, the equation for Flag resolves to a string literal. It is not safe to use SkipNoData in this scenario:

   WHEN Flag EQ "0" OR Flag EQ ""

   Flag = “Initialized”

   END WHEN

Note: The WHEN terms in this example are irrelevant, it is the line assigning a string literal to the Flag symbol that makes this equation unsafe for SkipNoData.

The following calculations all have single terms on the right-hand side, and because they are multiplied by a symbol, these terms do not resolve to a constant and therefore SkipNoData is safe to use:

A = B * VALUE(…)

C = B * 10

Syntax

SKIPNODATA "ON"|"OFF"            

Select one of the following:

CalculationBlock (...)                                     
  
Equation1
Equation2
  
SkipNoData "ON"
Equation3
SkipNoData "OFF"
  
Equation4
  
End CalculationBlock

See also

• Collect Statistics
• Delete Statistics