Campbell Scientific CR9000X Measurement and Control System - Manual (Page 197)

Section 6. Data Table Declarations and Output Processing Instructions
6.4 Output Processing Instructions
Average (Reps, Source, DataType, DisableVar)
This instruction stores the average value over the output interval for the source
variable or each element of the array specified.
Parameter Enter AVERAGE PARAMETERS
Reps Constant The number of averages to calculate. When Reps is greater than one, the source must be an array.
Source Var. The name of the Variable that is to be averaged.
DataType A code to select the data storage format. Read More: See Section 4.2.4.4 Data Types
Constant Alpha Code Numeric Code Data Format
IEEE4 24 IEEE 4 byte floating point
FP2 7 Campbell Scientific 2 byte floating point
UINT2 21 2 Byte unsigned integer
Long 20 4 Byte Integer value
DisableVar
Constant, Var.,
or Expression
A non-zero value will disable intermediate processing. Normally 0 is entered so all inputs are processed.
Example:When the disable variable is
≠0 the current input is not included in the average. The average
that is stored is the average of the inputs that occurred while the disable variable was 0.
Value Result
0 Process current input
≠ 0 Do not process current input
Covariance (NumVals, Source, DataType, DisableVar, NumCov)
Calculates the covariance of values in an array over time. The Covariance of
X and Y is calculated as:
( )
2
1 1 1 ) , (
n
Y X
n
Y X
Y X Cov
n
i
i
n
i
i
n
i
i i
∑ ∑ ∑
= = =
⋅
−
⋅
=
where is the number of values processed over the output interval and
and Y are the individual values of
n
i
X
i
X and Y .
Parameter Enter COVARIANCE PARAMETERS
NumVals Const The number of elements in the array to include in the covariance calculations
Source
Variable Array The array that contains the values from which to calculate the covariances. If the covariance
calculations are to start at some element of the array later than the first, include the element number
in the source (e.g., X(3)).
DataType A code to select the data storage format. Read More: See Section 4.2.4.4 Data Types
Constant Alpha Code Numeric Code Data Format
IEEE4 24 IEEE 4 byte floating point
FP2 7 Campbell Scientific 2 byte floating point
UINT2 21 2 Byte unsigned integer
Long 20 4 Byte Integer value
DisableVar A non-zero value will disable intermediate processing: input is not included in the Covariance.
Constant, Value Result
Variable, or 0 Process current input
Expression ≠ 0 Do not process current input
NumCov
Constant The number of covariances to calculate. The maximum number of covariances is Z/2*(Z+1). Where
Z= NumVals. If X(1) is the first specified element of the source array, the covariances are
calculated and output in the following sequence: X_Cov(1)…X_Cov(Z/2*(Z+1)) = Cov[X(1),X(1)],
Cov[X(1),X(2)],…Cov[X(1),X(Z)],…Cov[X(2),X(2)], Cov[X(2),X(Z)],…Cov[X(Z),X(Z)].
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