Apama 10.3 | Apama Documentation | Developing Apama Applications | Developing Apama Applications in Event Modeler | Using Standard Blocks | General analytic blocks | Data Distribution Calculator v2.0

Data Distribution Calculator v2.0
The Data Distribution Calculator block calculates some common statistics from a set of samples. Like the correlation block, the set of samples may be unlimited in size, or constrained by a maximum number of samples or a maximum age of samples. Note that execution of the Median and Mode Calculator block, Moving Average block or Statistics Calculator block is faster than execution of the Data Distribution Calculator block. This is because those blocks perform a subset of the processing of the Data Distribution Calculator block.
Parameters
 Parameter Description period The maximum age of any sample that is used in the calculations, in seconds. Any samples older than this will be discarded before performing the calculation. size The maximum number of samples that are used in the calculation. The oldest sample is replaced by the newest sample when the total number of samples has reached this limit.
One or both of the above parameters must be 0, in which case that limit is not imposed. It is not possible to restrict the number of samples by both age and number of samples, but it is possible to not impose any limit on the number of samples (thus an infinite set of samples is kept).
Operations
 Operation Description start Starts the calculation of statistics. Must be called before the calculator will generate any statistics. stop Stops the calculation of further statistics. Any subsequent input feeds are ignored. clear Discards all current data.
Input feeds
 Feed Fields Description data value The feed of values. The time of a value is taken to be the correlator's current time.
Output feeds
 Feed Fields Description statistics value The most recent value received in the input feed. mean The arithmetic mean of the distribution. mode The most commonly occurring value, if there is one. no unique mode true if there is no single mode. median The mid point of the ordered set of data values. standard deviation Standard deviation of the data set. variance Variance of the distribution. skew Degree of skewed-ness of the distribution. kurtosis Kurtosis measure of the distribution. samples The number of samples used for this calculation.