Variables can be mapped to run attributes that can have multiple values. When multiple values are present, calculations will execute and provide a singular value. For this reason the summarization method must be specified for each variable.
A quick review of terminology:
- Calculation: The act or result of running a formula.
- Formula: A set of variables used to calculate a value.
- Run Attribute: A value that can be mapped to a variable in the formula editor.
Potential scenarios where a variable might be mapped to multiple values:
- N runs on Step 1 merge onto M runs on Step 2. A formula that references a run attribute on Step 1 might have multiple upstream runs connected to it. A summarization method is needed to determine which values from which runs should be used.
- 1 run on Step 1 merges onto 1 run on Step 2. A formula that references a run attribute on Step 1 might reference a run attribute with a multivalued data block. A summarization method is needed to determine which values from the multi valued data block should be used.
- N runs on Step 1 merge onto M runs on Step 2. A formula that references a run attribute on Step 1 might have multiple upstream runs connected with each run attribute having a multivalued data block. A summarization method is needed to determine which values from which multivalued data block from which runs should be used.
Summarization methods vary based on the data types being mapped to a variable. A brief description for each summarization method is below. Unless otherwise noted "run" refers to all runs connected to the run that the calculation is being executed on.
Name |
Description |
Applies to |
Action Within a Run |
Action Across Runs |
first |
Returns the first value on the first connected run (by run number). |
any |
first |
first run by run number |
first by run end |
Returns the first value on the first connected run (by run end time). Ignores any runs without an end time. |
any |
first |
first run by end time |
first by run start |
Returns the first value on the first connected run (by run start time). Ignores any runs without a start time. |
any |
first |
first run by start time |
last |
Returns the last value on the last connected run (by run number). |
any |
last |
last run by run number |
last by run end |
Returns the last value on the last connected run (by run end time). Ignores any runs without an end time. |
any |
last |
last run by end time |
last by run start |
Returns the last value on the last connected run (by run start time). Ignores any runs without a start time. |
any |
last |
last run by start time |
max |
Finds the maximum value across all runs. |
numeric, datetime |
max |
max |
mean |
Averages all values as if they were one data set. |
numeric |
mean |
mean (weighted by number of values) |
mean of run means |
Averages values on each run, then averages the averages. |
numeric |
mean |
mean |
median |
Takes the median of all values as if they were one data set. |
numeric |
none |
median |
median of run medians |
Takes the median of values on each run, then the median of the medians. |
numeric |
median |
median |
min |
Finds the minimum value across all runs. |
numeric, datetime |
min |
min |
run count |
Counts the number of connected runs. |
any |
1 |
sum |
SD (pop) |
Takes the standard deviation of all values as if they were one population. |
numeric, datetime |
none |
standard deviation (population) |
SD (sam) |
Takes the standard deviation of all values as if they were a set of samples from one population. |
numeric |
none |
standard deviation (sample) |
sum |
Adds up all values across all runs. |
numeric |
sum |
sum |
value count |
Counts the number of values. |
any |
number of values |
sum |
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