Data Matching
Data Matching
Cov
Usage
This function is used to calculate the population covariance.
Name: COV
Input Series: Only support two input series. The types are both INT32 / INT64 / FLOAT / DOUBLE.
Output Series: Output a single series. The type is DOUBLE. There is only one data point in the series, whose timestamp is 0 and value is the population covariance.
Note:
- If a row contains missing points, null points or
NaN
, it will be ignored; - If all rows are ignored,
NaN
will be output.
Examples
Input series:
+-----------------------------+---------------+---------------+
| Time|root.test.d2.s1|root.test.d2.s2|
+-----------------------------+---------------+---------------+
|2020-01-01T00:00:02.000+08:00| 100.0| 101.0|
|2020-01-01T00:00:03.000+08:00| 101.0| null|
|2020-01-01T00:00:04.000+08:00| 102.0| 101.0|
|2020-01-01T00:00:06.000+08:00| 104.0| 102.0|
|2020-01-01T00:00:08.000+08:00| 126.0| 102.0|
|2020-01-01T00:00:10.000+08:00| 108.0| 103.0|
|2020-01-01T00:00:12.000+08:00| null| 103.0|
|2020-01-01T00:00:14.000+08:00| 112.0| 104.0|
|2020-01-01T00:00:15.000+08:00| 113.0| null|
|2020-01-01T00:00:16.000+08:00| 114.0| 104.0|
|2020-01-01T00:00:18.000+08:00| 116.0| 105.0|
|2020-01-01T00:00:20.000+08:00| 118.0| 105.0|
|2020-01-01T00:00:22.000+08:00| 100.0| 106.0|
|2020-01-01T00:00:26.000+08:00| 124.0| 108.0|
|2020-01-01T00:00:28.000+08:00| 126.0| 108.0|
|2020-01-01T00:00:30.000+08:00| NaN| 108.0|
+-----------------------------+---------------+---------------+
SQL for query:
select cov(s1,s2) from root.test.d2
Output series:
+-----------------------------+-------------------------------------+
| Time|cov(root.test.d2.s1, root.test.d2.s2)|
+-----------------------------+-------------------------------------+
|1970-01-01T08:00:00.000+08:00| 12.291666666666666|
+-----------------------------+-------------------------------------+
DTW
Usage
This function is used to calculate the DTW distance between two input series.
Name: DTW
Input Series: Only support two input series. The types are both INT32 / INT64 / FLOAT / DOUBLE.
Output Series: Output a single series. The type is DOUBLE. There is only one data point in the series, whose timestamp is 0 and value is the DTW distance.
Note:
- If a row contains missing points, null points or
NaN
, it will be ignored; - If all rows are ignored,
0
will be output.
Examples
Input series:
+-----------------------------+---------------+---------------+
| Time|root.test.d2.s1|root.test.d2.s2|
+-----------------------------+---------------+---------------+
|1970-01-01T08:00:00.001+08:00| 1.0| 2.0|
|1970-01-01T08:00:00.002+08:00| 1.0| 2.0|
|1970-01-01T08:00:00.003+08:00| 1.0| 2.0|
|1970-01-01T08:00:00.004+08:00| 1.0| 2.0|
|1970-01-01T08:00:00.005+08:00| 1.0| 2.0|
|1970-01-01T08:00:00.006+08:00| 1.0| 2.0|
|1970-01-01T08:00:00.007+08:00| 1.0| 2.0|
|1970-01-01T08:00:00.008+08:00| 1.0| 2.0|
|1970-01-01T08:00:00.009+08:00| 1.0| 2.0|
|1970-01-01T08:00:00.010+08:00| 1.0| 2.0|
|1970-01-01T08:00:00.011+08:00| 1.0| 2.0|
|1970-01-01T08:00:00.012+08:00| 1.0| 2.0|
|1970-01-01T08:00:00.013+08:00| 1.0| 2.0|
|1970-01-01T08:00:00.014+08:00| 1.0| 2.0|
|1970-01-01T08:00:00.015+08:00| 1.0| 2.0|
|1970-01-01T08:00:00.016+08:00| 1.0| 2.0|
|1970-01-01T08:00:00.017+08:00| 1.0| 2.0|
|1970-01-01T08:00:00.018+08:00| 1.0| 2.0|
|1970-01-01T08:00:00.019+08:00| 1.0| 2.0|
|1970-01-01T08:00:00.020+08:00| 1.0| 2.0|
+-----------------------------+---------------+---------------+
SQL for query:
select dtw(s1,s2) from root.test.d2
Output series:
+-----------------------------+-------------------------------------+
| Time|dtw(root.test.d2.s1, root.test.d2.s2)|
+-----------------------------+-------------------------------------+
|1970-01-01T08:00:00.000+08:00| 20.0|
+-----------------------------+-------------------------------------+
Pearson
Usage
This function is used to calculate the Pearson Correlation Coefficient.
Name: PEARSON
Input Series: Only support two input series. The types are both INT32 / INT64 / FLOAT / DOUBLE.
Output Series: Output a single series. The type is DOUBLE. There is only one data point in the series, whose timestamp is 0 and value is the Pearson Correlation Coefficient.
Note:
- If a row contains missing points, null points or
NaN
, it will be ignored; - If all rows are ignored,
NaN
will be output.
Examples
Input series:
+-----------------------------+---------------+---------------+
| Time|root.test.d2.s1|root.test.d2.s2|
+-----------------------------+---------------+---------------+
|2020-01-01T00:00:02.000+08:00| 100.0| 101.0|
|2020-01-01T00:00:03.000+08:00| 101.0| null|
|2020-01-01T00:00:04.000+08:00| 102.0| 101.0|
|2020-01-01T00:00:06.000+08:00| 104.0| 102.0|
|2020-01-01T00:00:08.000+08:00| 126.0| 102.0|
|2020-01-01T00:00:10.000+08:00| 108.0| 103.0|
|2020-01-01T00:00:12.000+08:00| null| 103.0|
|2020-01-01T00:00:14.000+08:00| 112.0| 104.0|
|2020-01-01T00:00:15.000+08:00| 113.0| null|
|2020-01-01T00:00:16.000+08:00| 114.0| 104.0|
|2020-01-01T00:00:18.000+08:00| 116.0| 105.0|
|2020-01-01T00:00:20.000+08:00| 118.0| 105.0|
|2020-01-01T00:00:22.000+08:00| 100.0| 106.0|
|2020-01-01T00:00:26.000+08:00| 124.0| 108.0|
|2020-01-01T00:00:28.000+08:00| 126.0| 108.0|
|2020-01-01T00:00:30.000+08:00| NaN| 108.0|
+-----------------------------+---------------+---------------+
SQL for query:
select pearson(s1,s2) from root.test.d2
Output series:
+-----------------------------+-----------------------------------------+
| Time|pearson(root.test.d2.s1, root.test.d2.s2)|
+-----------------------------+-----------------------------------------+
|1970-01-01T08:00:00.000+08:00| 0.5630881927754872|
+-----------------------------+-----------------------------------------+
PtnSym
Usage
This function is used to find all symmetric subseries in the input whose degree of symmetry is less than the threshold.
The degree of symmetry is calculated by DTW.
The smaller the degree, the more symmetrical the series is.
Name: PATTERNSYMMETRIC
Input Series: Only support a single input series. The type is INT32 / INT64 / FLOAT / DOUBLE
Parameter:
window
: The length of the symmetric subseries. It's a positive integer and the default value is 10.threshold
: The threshold of the degree of symmetry. It's non-negative. Only the subseries whose degree of symmetry is below it will be output. By default, all subseries will be output.
Output Series: Output a single series. The type is DOUBLE. Each data point in the output series corresponds to a symmetric subseries. The output timestamp is the starting timestamp of the subseries and the output value is the degree of symmetry.
Example
Input series:
+-----------------------------+---------------+
| Time|root.test.d1.s4|
+-----------------------------+---------------+
|2021-01-01T12:00:00.000+08:00| 1.0|
|2021-01-01T12:00:01.000+08:00| 2.0|
|2021-01-01T12:00:02.000+08:00| 3.0|
|2021-01-01T12:00:03.000+08:00| 2.0|
|2021-01-01T12:00:04.000+08:00| 1.0|
|2021-01-01T12:00:05.000+08:00| 1.0|
|2021-01-01T12:00:06.000+08:00| 1.0|
|2021-01-01T12:00:07.000+08:00| 1.0|
|2021-01-01T12:00:08.000+08:00| 2.0|
|2021-01-01T12:00:09.000+08:00| 3.0|
|2021-01-01T12:00:10.000+08:00| 2.0|
|2021-01-01T12:00:11.000+08:00| 1.0|
+-----------------------------+---------------+
SQL for query:
select ptnsym(s4, 'window'='5', 'threshold'='0') from root.test.d1
Output series:
+-----------------------------+------------------------------------------------------+
| Time|ptnsym(root.test.d1.s4, "window"="5", "threshold"="0")|
+-----------------------------+------------------------------------------------------+
|2021-01-01T12:00:00.000+08:00| 0.0|
|2021-01-01T12:00:07.000+08:00| 0.0|
+-----------------------------+------------------------------------------------------+
XCorr
Usage
This function is used to calculate the cross correlation function of given two time series.
For discrete time series, cross correlation is given by
which represent the similarities between two series with different index shifts.
Name: XCORR
Input Series: Only support two input numeric series. The type is INT32 / INT64 / FLOAT / DOUBLE.
Output Series: Output a single series with DOUBLE as datatype.
There are data points in the series, the center of which represents the cross correlation
calculated with pre-aligned series(that is in the formula above),
and the previous(or post) values represent those with shifting the latter series forward(or backward otherwise)
until the two series are no longer overlapped(not included).
In short, the values of output series are given by(index starts from 1)
Note:
null
andNaN
values in the input series will be ignored and treated as 0.
Examples
Input series:
+-----------------------------+---------------+---------------+
| Time|root.test.d1.s1|root.test.d1.s2|
+-----------------------------+---------------+---------------+
|2020-01-01T00:00:01.000+08:00| null| 6|
|2020-01-01T00:00:02.000+08:00| 2| 7|
|2020-01-01T00:00:03.000+08:00| 3| NaN|
|2020-01-01T00:00:04.000+08:00| 4| 9|
|2020-01-01T00:00:05.000+08:00| 5| 10|
+-----------------------------+---------------+---------------+
SQL for query:
select xcorr(s1, s2) from root.test.d1 where time <= 2020-01-01 00:00:05
Output series:
+-----------------------------+---------------------------------------+
| Time|xcorr(root.test.d1.s1, root.test.d1.s2)|
+-----------------------------+---------------------------------------+
|1970-01-01T08:00:00.001+08:00| 0.0|
|1970-01-01T08:00:00.002+08:00| 4.0|
|1970-01-01T08:00:00.003+08:00| 9.6|
|1970-01-01T08:00:00.004+08:00| 13.4|
|1970-01-01T08:00:00.005+08:00| 20.0|
|1970-01-01T08:00:00.006+08:00| 15.6|
|1970-01-01T08:00:00.007+08:00| 9.2|
|1970-01-01T08:00:00.008+08:00| 11.8|
|1970-01-01T08:00:00.009+08:00| 6.0|
+-----------------------------+---------------------------------------+