Preservation Metrics
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      Downsampling in Analytics

      The graph says data is downsampled. What does this mean?

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      What does downsampling do?

      Downsampling in Analytics is a key feature that improves performance dramatically. It is meant to:

      1. Reduce the number of data points to be plotted, particularly when there are more than will fit on the pixels in your screen;

      2. Preserve the "shape" of the data (i.e. the peaks and troughs, etc.) so that even when you are looking at fewer data points you preserve the "information" contained within the larger dataset.

      How does it do it?

      We are using the algorithm called Largest Triangle Three Buckets (LTTB), which you can find here.

      What does it look like?

      Without downsampling - 31 days or less

      20250307-NON-Downsampled-data-31-days-example

      With downsampling - 32 days or more

      20250307-Downsampled-data-32-days-example

      How does it affect data?

      Downsampling is a visualization tactic to make graphs load faster, while still retaining their accurate shape. 

      Downsampling is applied in the application when a chart is loaded, and does not affect your raw data.

      Metrics are not being affected by downsampling. All data points are being taken into account for calculations.

      Can it be turned off?

      No, downsampling will be automatic when you are trying to show a period in a graph of 32 days or longer. It will automatically turn off if you reduce that period to under 32 days or if you zoom into your graph, effectively going under the 32-day limit.

      Can you see missed readings when data is downsampled?

      If you are using the Show Dots display option, you will see large gaps, but not small ones in large amounts of downsampled data. This is no different than data that has not been downsampled.

      If you zoom in, the same applies. Large gaps will be visible, but not small ones. Once you zoom in enough to go under the 32 day limit, downsampling will turn off and every gap will be visible.

      Show dots view of temperature without downsampling - 31 days or less

      20250307-NON-Downsampled-data-31-days-temperature-with-dots

      Show dots view of temperature with downsampling - 32 days or more

      20250307-Downsampled-data-31-days-temperature-with-dots

      How do I know if downsampling is on or off?

      You will see a message on the top right of your Analytics graph that says Data is downsampled ⓘ. 

      You will see a small explanation of what that means if you hover over the information icon.