SkewnessInTime('Expression','Interval','Reset=0')
Arguments
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'Expression' |
Measured value, for which the skewness is formed |
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'Interval' |
Specification of the interval length in seconds, over which the skewness should be calculated. |
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'Reset' |
Optional parameter (default = 0) to stop and restart the calculation |
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'Reset' = 0 |
Perform calculation |
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'Reset' = 1 |
Stop calculation and set result to 0 |
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'Reset' = 2 |
Stop calculation and keep result |
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'Reset' = 3 |
Calculate now and then stop calculation |
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Description
Like the kurtosis factor, the skewness factor can be used for evaluating and analyzing oscillations. The skewness factor can be used if the symmetrical properties of an oscillation signal are to be checked (e.g. acceleration signal).
With this function, the selected expression is divided into equal-duration intervals of size 'Interval'. For these intervals, the skewness is subsequently calculated.
In mathematical terms, this is the evaluation of the skewness of a distribution function. A distribution is called right-skewed (or positively-skewed) when the majority of the distribution is concentrated on the left side. A distribution is called left-skewed (or negatively-skewed) when the majority of the distribution is concentrated on the right. The skewness level is defined by the third order of the central moment of the distribution.
The procedure to calculate the skewness is similar to that of the KurtosisInTime function.