MongoDB Charts custom binning for percentages

Question

In MongoDB Charts I created an Circular Donut to view the average of my property score. This score ranges from 0 to 100 (including) as it is score based on percentage. I want the scores to be aggregated up to steps of 10%, except the first and last 10%. To clearify, I want the donut to show these aggregations:

0-9%, 10-19%, up to 80-89%, 90-99%, 100%

If I use the BINNING ON with BIN SIZE 10 in MongoDB Charts, I get the following:

0-10%, 10-20%, up to 80-90% 90-100%, 100-110%

If something is exacly 100%, it will be added to the 100-110%, this could mean that the calculation is already good but the naming of the ranges is bad.

How do I set this custom data binning?

Answer 1

What I would do is treat your data as categories. You can map each data point to a new label value based on their interval.

Are you able to write a map query to do this conversion?https://docs.mongodb.com/manual/reference/operator/aggregation/map/

For example:

all data points from 0 to 9 -> "0-9"
all data points from 10 to 19 -> "10-19" 
...
all data points == 100 -> "100"

After the binning is going to be easy and you can probably remap the labels to be more readable.