Campbell CR9000, Инструкция по эксплуатации

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Section 8. Processing and Math Instructions
8-5
Cosine
Returns the cosine of an angle .
Syntax
Cos(
angle
)
Remarks
The argument angle can be any valid numeric expression measured in radians.
The Cos function takes an angle and returns the ratio of two sides of a right
triangle. The ratio is the length of the side adjacent to the angle divided by the
length of the hypotenuse. The result lies in the range -1 to 1.
To convert degrees to radians, multiply degrees by Pi/180. To convert radians to
degrees, multiply radians by 180/Pi. Pi is approximately 3.141593.
Cos FunctionExample
The example uses Cos to calculate the cosine of an angle with a user-specified
number of degrees.
Dim Degrees, Pi, Radians, Ans 'Declare variables.
BeginProg
Pi = 4 * Atn(1)
'Calculate Pi.
Degrees = Volts(1) 'Get value to convert.
Radians = Degrees * (Pi / 180) 'Convert to radians.
Ans = Cos( Radians ) ‘The Cosine of Degrees.
EndProg
Spatial Covariance
The CovSpa instruction computes the covariance(s) of sets of data that are
loaded into arrays.
Syntax
CovSpa (Dest, NumOfCov, SizeOfSets, CoreArray; DatArray)
CovSpa calculates the covariance(s) between the data in the CoreArray and
one or more data sets in the DatArray. The covariance of the sets of
data
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 n is the number of values in each data set ( SizeofSets ).
i
X
and
i
Y
are
the individual values of
X
and
Y
.