The values returned by the data source are plotted on a chart, and they have value label on the graph. I would like to change the value string to a custom label, but I cannot find how do it.
We have deprecated MutableDataFrame (pull request), you should be able to just use DataFrame instead.
You should be able to do this with field overrides. In the panel options on the right add a field override, in the “Fields with name” select “value”, then after clicking on “Add override property” select “Standard options → Display name” and set a custom label.
I am interested in changing the “display name” from the data source itself. Assume that the data source returns some metrics per city. I would like the user to query metrics for, say, New York, and I would like the default label to be “New York” instead of “value”. Is that possible?