23 lines
427 B
Text
23 lines
427 B
Text
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procedure main()
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stddev() # reset state / empty
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every s := stddev(![2,4,4,4,5,5,7,9]) do
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write("stddev (so far) := ",s)
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end
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procedure stddev(x) # running standard deviation
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static X,sumX,sum2X
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if /x then { # reset state
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X := []
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sumX := sum2X := 0.
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}
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else { # accumulate
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put(X,x)
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sumX +:= x
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sum2X +:= x^2
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return sqrt( (sum2X / *X) - (sumX / *X)^2 )
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}
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end
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