Base value (position of the Y-axis) on a sparkline.
Setting this value to null causes the chart to calculate the base value automatically so the chart fills the vertical extent of the cell. This is a good option to highlight relative changes, and is used by default for Sparklines of type Line.
Setting this value to an absolute number (like zero) is a better option to show absolute changes, and is used by default for Sparklines of type Column.
Maximum number of points to use in the sparkline or sparkbar.
Setting this value to null causes the cell to show all points.
Specifies parameters used to create Sparkline cells with the makeSparkline method.