Calculations on search results enables the calculation of a summary metric for a tag of interest (e.g., calculate the maximum temperature attained during a batch) over the time interval of your search results (e.g., historically produced batches of a given product).
How to perform a calculation on search results
- After performing your search, click the âAdd calculationâ link on the search summary. The following panel will appear:
- Select a tag on which to perform the calculation (Tag to aggregate). You can select from the active tags or other tags.
Note: If you select other tags (not from the active tag list), these tags will not be added to the active tag list. Also, when opening a saved search, only the tags which are used in the search condition are added to the active tag list.
- Select a calculation or aggregation 'Operator':
- 'Average'.
- 'Minimum'.
- 'Maximum'.
- 'Range': maximum value - minimum value.
- 'Start value': value at the starting point of the interval.
- 'End value': value at the end point of the interval.
- 'Delta': end value - start value.
- 'Integral (/1d)': area under the curve, assuming the tag to aggregate is expressed in units per day. If it has another dimension (e.g., kg/h) the user needs to consider a conversion factor (e.g., x24 hours/day if your tag is expressed in units/h) to obtain the correct integral value.
- 'Standard deviation': calculation of the standard deviation over the entire time frame per tag.
- Optionally, assign your calculation a name and indicate a unit of measurement.
- Click on the button âAdd calculationâ.
Note: You can add up to 30 calculations by repeating the previous steps.
- When you are done adding your calculations to the Available calculations list, click on the "Apply" button to start the calculation(s).
The calculations are performed and presented in your search results. Select the calculation you have interest in to see it displayed.
Tags used in the calculations are not necessarily part of the search conditions as well. In the unlikely case that these tags have never been used before, they have not yet been indexed. In this situation, a warning message will be shown to indicate that TrendMiner was unable to perform the calculation. Simply adding the tag to the active tag list, will initiate the indexation process.
To sort the search results based on the selected calculation, use the sorting options in the Search results menu. Look to the Working with the search results list article to learn more.
Note: The definition of the calculation remains available after editing the search conditions, which means they will be performed when running the search.
Note: The calculations can be saved as part of the search definition when saving the search. This allows you to easily reproduce your complete analysis. For more information about creating searches please refer to the Search overview article for specific search type.
Manage calculations
After adding some calculations, you can manage them by clicking on the link âManage calculationsâ on the search summary.
This action will open the calculations dialog where you can remove or add more calculations. Click "Apply" to confirm your changes.