Calculates the moving block minimum of a series given a duration.
XBLOCKMIN(series, xdur, "naflag")
series |
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A series or table |
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xdur |
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A real, the X duration used to compute the integer number of samples for the non-overlapping moving interval. |
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"naflag" |
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Optional. A string, the NA handling method.
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A series or table.
W1: {1, 2, 4, 7};setdeltax(1/100)
W2: blockmin(w1, 3)
W3: xblockmin(w1, 0.02)
W1 contains the input data with a sample rate of 100 Hz.
W2 computes a 3 point moving block minimum.
W3 computes the same moving block minimum except the block size is specified in terms of seconds. Since a 0.02 interval equates to 3 samples, both functions return the series {1, 7}.
W1: integ(gnorm(10000, 1/10000)) * 1000
W2: blockmin(w1, 51)
W3: xblockmin(w1, 0.005)
W4: W2 - W3
W1 synthesizes 10000 samples of data with a sample rate of 10kHz.
W2 computes a 51 point block minimum.
W3 computes a moving block minimum with an interval of 0.005 seconds. Since a 0.005 interval equates to 51 samples, the two block minimums are identical.
W1: {1, 2, 3, 4, 5, nan, 7, 8, nan, 10, 11, 12};setdeltax(1/100)
W2: xblockmin(W1, 0.02)
W3: xblockmin(W1, 0.02, "includenan")
W2 == {1, 4, 7, 10}
W3 == {1, nan, nan, 10}
W2 ignores all NA values by removing the NaN from the segment and adjusting the segment size.
W3 includes NaNs and produces an NaN if the segment includes an NaN.
XBLOCKMIN computes a moving minimum with non-overlapping blocks of duration xdur.
The block duration xdur is converted to the integer block interval N with:
N = xdur / deltax(s) + 1
where xdur >= deltax(s)
If the block size is not an integral fraction of the series length, the end points are not processed.
NaN values are ignored by default. Set naflag to "includenan" to process NaN values.
See BLOCKMIN to compute the N-point block minimum.