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EXOR
ASSET MANAGER ADMIN GUIDE
ASSET REFERENCE DATA
2.12.3 Biased Variance (NM3ENG_DYNSEG.GET_BIASED_VARIANCE)
This function returns the Biased Variance of the values of the specified attribute for each ‘chunk’ of network within the
selected region of interest. The Biased Variance is a measure of how spread out a distribution is. It is computed as the
Biased Average squared deviation of each number from its Mean. The formula used is:
Biased Variance = ∑(X - µ)²
N-1
Where X is the attribute value, µ is the Mean (see page 118) and N is the number of values in the range.
Syntax (for use in Merge File Definition – NM7055)
NM3ENG_DYNSEG.GET_BIASED_VARIANCE(SEC.NQR_MRG_JOB_ID,SEC.NMS_MRG_SECTION_ID,'CORO',
'L','IIT_NAASRA_LANE').
Where ‘CORO’ is the required Asset Type, ‘L’ is the required XSP (optional) and ‘IIT_NAASRA_LANE’ is the View
Column Name for the required Attribute (as defined in Asset Metamodel – NM0410).
Figure 114 displays an example where the Biased Variance for Roughness values is calculated for an Engineering
Dynamic Segmentation analysis on Traffic Sections and Roughness values.
Figure 114
The Biased Variance of the Roughness values for the Zone represented by T1 would be calculated as follows:
∑((30–27.66)² + (25–27.66)² + (22–27.66)² + (31–27.66)² + (28–27.66)² + (30–27.66)²) = 12.66
(6-1)
Figure 115
Version: 4.7
120
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