The Rate Of Change (ROC) measures the percent change of value compared to "N" periods ago.
In the stock market field, this indicator is simply referred to as "Momentum", as it indicates the speed at which values are changing. It is similar to a normalized form of Slope. A positive ROC indicates that values are increasing, while a negative ROC indicates values are decreasing.
ROC = [(Close - Close N periods ago) / (Close N periods ago)]
Defines the time series data fed into the function. This can be a sensor ID or another function.
Number of data intervals considered in the function
*Input data is optional in most cases. If Info360 detects that the first input is time series data, it will be applied to the function. Otherwise, the current active sensor's data will be used, which is often the case in Reference Charts.
Example Usage as an Expression:
ROC(2)*100 - calculates the percentage change in value over the past interval.
Example Reference Chart:
The following chart illustrates the impact of varying the interval for the Rate of Change calculation. For tanks that fill and drain over several intervals, the rate of change increases as the interval increases (because the change over a longer interval is greater), but it also introduces a time lag in the results. Notice after the tank begins filling again in the middle of the chart, that the ROC(6) shows a negative rate of change for several intervals since it is still comparing with older higher tank levels.
For information on setting up custom equations and syntax, please refer to Analytical Functions.