IoTDB-Quality

# Histogram

# Usage

This function is used to calculate the distribution histogram of a single column of numerical data.

Name: HISTOGRAM

Input Series: Only supports a single input sequence, the type is INT32 / INT64 / FLOAT / DOUBLE

Parameters:

  • start: The lower limit of the requested data range, the default value is -Double.MAX_VALUE.
  • end: The upper limit of the requested data range, the default value is Double.MAX_VALUE, and the value of start must be less than or equal to end.
  • count: The number of buckets of the histogram, the default value is 1. It must be a positive integer.

Output Series: The value of the bucket of the histogram, where the lower bound represented by the i-th bucket (index starts from 1) is and the upper bound is .

Note:

  • If the value is lower than start, it will be put into the 1st bucket. If the value is larger than end, it will be put into the last bucket.
  • Missing points, null points and NaN in the input series will be ignored.

# Examples

Input series:

+-----------------------------+---------------+
|                         Time|root.test.d1.s1|
+-----------------------------+---------------+
|2020-01-01T00:00:00.000+08:00|            1.0|
|2020-01-01T00:00:01.000+08:00|            2.0|
|2020-01-01T00:00:02.000+08:00|            3.0|
|2020-01-01T00:00:03.000+08:00|            4.0|
|2020-01-01T00:00:04.000+08:00|            5.0|
|2020-01-01T00:00:05.000+08:00|            6.0|
|2020-01-01T00:00:06.000+08:00|            7.0|
|2020-01-01T00:00:07.000+08:00|            8.0|
|2020-01-01T00:00:08.000+08:00|            9.0|
|2020-01-01T00:00:09.000+08:00|           10.0|
|2020-01-01T00:00:10.000+08:00|           11.0|
|2020-01-01T00:00:11.000+08:00|           12.0|
|2020-01-01T00:00:12.000+08:00|           13.0|
|2020-01-01T00:00:13.000+08:00|           14.0|
|2020-01-01T00:00:14.000+08:00|           15.0|
|2020-01-01T00:00:15.000+08:00|           16.0|
|2020-01-01T00:00:16.000+08:00|           17.0|
|2020-01-01T00:00:17.000+08:00|           18.0|
|2020-01-01T00:00:18.000+08:00|           19.0|
|2020-01-01T00:00:19.000+08:00|           20.0|
+-----------------------------+---------------+

SQL for query:

select histogram(s1,"start"="1","end"="20","count"="10") from root.test.d1

Output series:

+-----------------------------+-----------------------------------------------------------------+
|                         Time|histogram(root.test.d1.s1, "start"="1", "end"="20", "count"="10")|
+-----------------------------+-----------------------------------------------------------------+
|1970-01-01T08:00:00.000+08:00|                                                                2|
|1970-01-01T08:00:00.001+08:00|                                                                2|
|1970-01-01T08:00:00.002+08:00|                                                                2|
|1970-01-01T08:00:00.003+08:00|                                                                2|
|1970-01-01T08:00:00.004+08:00|                                                                2|
|1970-01-01T08:00:00.005+08:00|                                                                2|
|1970-01-01T08:00:00.006+08:00|                                                                2|
|1970-01-01T08:00:00.007+08:00|                                                                2|
|1970-01-01T08:00:00.008+08:00|                                                                2|
|1970-01-01T08:00:00.009+08:00|                                                                2|
+-----------------------------+-----------------------------------------------------------------+

# examples on zeppelin

link: http://101.6.15.213:18181/#/notebook/2GC1HE97R (opens new window)

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