CPlotView:GetPtX

The GetPtX method returns the x value of a point in the class data matrix.

Syntax

x = CPlotView:GetPtX( n )

n is the index of the point in the data array.

x is the x coordinate.

On success, this method returns the x coordinate.

On failure, this method returns 0.

This method returns the x value of the specified point at index n. If n is out of range, the value 0 is returned. To remove ambiguity about whether the point truly has a value of 0 or is out of bounds, check the index before calling this method.

Example

The following script adds some points, then finds the nearest point and prints its x value:

P = CPlotView:new()	-- create a new CPlotView
P:Add( 11.82, 70.5, 10.25, 12.5)	-- add a point
P:Add( 4.62, 90.5, 11.5, 10.2)	-- add a point
n = P:FindPoint( 4, 72)	-- get index of point nearest 4,72
Printf("n=%d, x=%lg\n", n, P:GetPtX(n))	-- result: n = 1, x = 11.82