Specifications

Section 8. Processing and Math Instructions
8-32
StdDevSpa (Dest, Swath, Source)
Used to find the standard deviation of an array.
Syntax
StdDevSpa(Dest, Swath, Source)
Remarks
The spatial standard deviation is calculated as
Dest Xi Xi swath swath
ij
ijswath
ij
ijswath
=−
⎛
⎝
⎜
⎞
⎠
⎟
⎛
⎝
⎜
⎞
⎠
⎟
⎛
⎝
⎜
⎞
⎠
⎟
=
=+
=
=+
∑∑
() () / /
2
2
1
2
Where X(j) = Source
Parameter
& Data Type
Enter
Dest
Variable or
Array
The variable in which to store the results of the instruction.
Swath
Constant
The number of elements to include in the calculation.
Source
Array
The name of the first variable in the array for which the standard deviation
should be calculated.
StrainCalc (Dest, Reps, Source, BrZero, BrConfig, GageFactpr,
PoissonFactor)
Converts the output of a bridge measurement instruction to microstrain.
Syntax
StrainCalc (Dest, Reps, Source, BrZero, BrConfig, GageFactpr,
PoissonFactor)
Remarks
Calculates microstrain, µ∈, from the appropriate formula for the bridge
configuration. All are electrically full bridges, the quarter bridge, half bridge
and full bridge strain gages refer to the number of active elements (i.e., strain
gages), 1,2, or 4 respectively.
Parameter
& Data Type
Enter
Dest
Variable or
Array
Variable to store strain in.
Reps
Constant
Number of strains to calculate, Destination, Source, and BrZero variables
must be dimensioned accordingly.
Source
Variable
The source variable array for the measurement(s), the input is expected as
millivolts out per volt in (the result of the full bridge instruction with a
multiplier of 1 and an offset of 0.