Programmer Guide/Command Reference/EVAL/var: Difference between revisions
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Compute the variance of ''x''. | |||
---- | |||
The variance of | ;Usage 1: <code>var(''x''<sub>vector</sub>)<code> | ||
;Result 1: The variance ''v'' of vector ''x''. | |||
:<code>''v'' = sum<sub>i = 0..ncol(''x'')</sub> ( (x<sub>i</sub> - avr(''x''))^2 ) | |||
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Revision as of 13:08, 8 April 2011
Compute the variance of x.
- Usage 1
var(xvector)- Result 1
- The variance v of vector x.
v = sumi = 0..ncol(x) ( (xi - avr(x))^2 )
Usage:
var(xv)
Result type:
scalar
The covariance of the vector xv and yv.
Usage:
var(xv,ys)
Result type:
scalar
The covariance matrix for the column vector of the matrix xM. The column average a[j] is either calculated with avr(xM[*,j]) or through the argument y (a[j] = yS or a[j] = yV[j]).
Usage:
var(xm)
var(xm,ys)
var(xm,yv)
Result type:
matrix - (ncol(xm) x ncol(xm))
