After: Relative months. Can see how the two compare after 6 months
This guide will show you how to make dates relative to each other in charts.
The use case explored here is one where you are tracking entities of some kind, such as a Communities, Water Service Providers (WSP), or Water Systems, and want to see monitoring results on dates relative to the first monitoring visit. For example, if the first WSP is visited in January for the first time, and April for the second time, you can make the visits show as month 0 and month 3 instead. This also makes it easier to compare progress between different WSPs, or sites in general.
Note: It is necessary that surveys are linked to a site for the system to understand that they are linked to each other.
Creating a chart with relative dates
The principle is that we want to map an axis by the relevant date field for each survey response relative to the first comparable date field value for a given site. The key trick is to go from the survey to the site and then to the survey again and apply a Minimum formula to get at the first date field.
Step 1) Collect data that is linked to Sites. For example one tracking Water Service Provider performance
Step 2) Create a chart widget
Step 3) Select the Data Source you want to track
Step 4) For the Horizontal axis we select the Months between or Days between Formula. Select Whole Numbers as the number format.
Step 4: Select Months between or Days between as the formula
Step 5) The key step to get the relative date. Go from the survey to the attached site, and from the site, go back to the survey and select Advanced...
Step 5: Go from the Survey to the Site and then Survey again
Step 6) To get the first survey date, select the Minimum Formula and then the date field you want to compare against.
Step 7) Select the appropriate value as the Vertical Axis
