Variation Trend Calculation Functions

Currently, IoTDB supports the following variation trend calculation functions:

Function NameAllowed Input Series Data TypesOutput Series Data TypeDescription
TIME_DIFFERENCEINT32 / INT64 / FLOAT / DOUBLE / BOOLEAN / TEXTINT64Calculates the difference between the time stamp of a data point and the time stamp of the previous data point. There is no corresponding output for the first data point.
DIFFERENCEINT32 / INT64 / FLOAT / DOUBLESame type as the input seriesCalculates the difference between the value of a data point and the value of the previous data point. There is no corresponding output for the first data point.
NON_NEGATIVE_DIFFERENCEINT32 / INT64 / FLOAT / DOUBLESame type as the input seriesCalculates the absolute value of the difference between the value of a data point and the value of the previous data point. There is no corresponding output for the first data point.
DERIVATIVEINT32 / INT64 / FLOAT / DOUBLEDOUBLECalculates the rate of change of a data point compared to the previous data point, the result is equals to DIFFERENCE / TIME_DIFFERENCE. There is no corresponding output for the first data point.
NON_NEGATIVE_DERIVATIVEINT32 / INT64 / FLOAT / DOUBLEDOUBLECalculates the absolute value of the rate of change of a data point compared to the previous data point, the result is equals to NON_NEGATIVE_DIFFERENCE / TIME_DIFFERENCE. There is no corresponding output for the first data point.

Example:

  1. select s1, time_difference(s1), difference(s1), non_negative_difference(s1), derivative(s1), non_negative_derivative(s1) from root.sg1.d1 limit 5 offset 1000;

Result:

  1. +-----------------------------+-------------------+-------------------------------+--------------------------+---------------------------------------+--------------------------+---------------------------------------+
  2. |                         Time|     root.sg1.d1.s1|time_difference(root.sg1.d1.s1)|difference(root.sg1.d1.s1)|non_negative_difference(root.sg1.d1.s1)|derivative(root.sg1.d1.s1)|non_negative_derivative(root.sg1.d1.s1)|
  3. +-----------------------------+-------------------+-------------------------------+--------------------------+---------------------------------------+--------------------------+---------------------------------------+
  4. |2020-12-10T17:11:49.037+08:00|7360723084922759782|                              1|      -8431715764844238876|                    8431715764844238876|    -8.4317157648442388E18|                  8.4317157648442388E18|
  5. |2020-12-10T17:11:49.038+08:00|4377791063319964531|                              1|      -2982932021602795251|                    2982932021602795251|     -2.982932021602795E18|                   2.982932021602795E18|
  6. |2020-12-10T17:11:49.039+08:00|7972485567734642915|                              1|       3594694504414678384|                    3594694504414678384|     3.5946945044146785E18|                  3.5946945044146785E18|
  7. |2020-12-10T17:11:49.040+08:00|2508858212791964081|                              1|      -5463627354942678834|                    5463627354942678834|     -5.463627354942679E18|                   5.463627354942679E18|
  8. |2020-12-10T17:11:49.041+08:00|2817297431185141819|                              1|        308439218393177738|                     308439218393177738|     3.0843921839317773E17|                  3.0843921839317773E17|
  9. +-----------------------------+-------------------+-------------------------------+--------------------------+---------------------------------------+--------------------------+---------------------------------------+
  10. Total line number = 5
  11. It costs 0.014s