Understand statistic options

If a content item or graphic has the Statistic property, you can choose the metric that will be used for the data that is displayed.

• Average

  CONNECT visualization uses a time-weighted average algorithm to calculate each data value shown.

  With the average, values are multiplied by the time difference between the points to determine the time-weighted value. So, the longer a stream had a particular value, the more weight that value holds in the overall average. The overall average is determined by adding all of the time-weighted values and then dividing that number by the total amount of time.

  Stair-step interpolation is used for the the time-weighted average. The formula is:

  ((P1 x (T2 - T1)) + (P2 x (T3 - T2)) + (P3 x (T4 - T3))) / (T4 - T1) = Average

• Maximum

  The maximum value from the actual data values within the time range. If there are no actual data points stored on the historian for a given cycle, nothing is returned. NULL is returned if the cycle contains one or more NULL values.

  Maximum retrieval only works with analog data. For all other data, normal delta results are returned.

• Minimum

  The minimum value from the actual data values within the time range. If there are no actual data points stored on the historian for a given cycle, nothing is returned. NULL is returned if the cycle contains one or more NULL values.

  Minimum retrieval only works with analog data. For all other data, normal delta results are returned.

• Last

  The final data value recorded for the time range.

The following additional options are available for the Statistic property for graphics:

• Current

  Returns the most recent value available, regardless of the time range.

• Count

  The total number of values recorded in the time period, including duplicate values. Count only works with analog data.

• StDev

  The time-weighted standard deviation calculated from values within the time range. The value is calculated using time-weighted sums and time-weighted sums of squares.

• First

  The first value that occurs within the time range.