When you add a row count measure, it appears as “Count of Rows” by default. You can change this label to whatever you want.
Here’s the default label.

You can specify a new label in the derivedMeasures section of the XMD. Because you’re counting rows and not a particular field, use * as the field name.
"derivedMeasures": [{
"field": "*",
"label": "Data Points"
}],
This change yields the following results.

See Also