The dimensions ChartSeries.getDimensionValues reads (Excel.ChartSeriesDimension). A scatter's points are XValues and YValues; every other chart's are Categories and Values.
ChartSeries.getDimensionValues
Excel.ChartSeriesDimension
XValues
YValues
Categories
Values
The dimensions
ChartSeries.getDimensionValuesreads (Excel.ChartSeriesDimension). A scatter's points areXValuesandYValues; every other chart's areCategoriesandValues.