CPlotView:Add

CPlotView:Add

The Add method appends the class data matrix with a point value. The point specifies x,y coordinates and, optionally, x- and/or y- error bars. See the remarks section to understand the different syntax used for each case.

Syntax

nIndex = CPlotView:Add( x, y, xErr, yErr, nDrawMode )

x, y are the x and y coordinates of the point.
xErr is an optional value of the x error bar (or the y error bar; see Remarks)
yErr is an optional value for a y error bar.
nDrawMode is an optional argument that describes how to interpret this point (see Remarks).
nIndex is the index at which this point was added. On success, this method returns nIndex > 0, on failure it returns 0.

Remarks

The point is appended to the end of the class data matrix. The return value gives the index of the point in the data array.

This method has several forms:

Add an x,y pair using Add( x, y )
Add an x,y pair with a y error bar using Add( x, y, ye )
Add an x,y pair with both x- and y- error bars using Add( x, y, xe, ye )
To add only an x error bar, use Add( x, y, xe, 0 ).
To use drawing mode, specify all 5 parameters. If no error bars are desired, set xe and/or ye to 0. The drawing mode, nDrawMode, is described below.

The error bar is specified as 1/2 of the total error bar length so that the specified length is drawn on each side of the point. For example, specifying the standard deviation, sigma, causes an error bar to be drawn from (value + sigma) to (value - sigma).

After points are added, call PlotPoints to create a new plot window or update the existing plot window.

Using the Drawing Mode

The drawing mode controls whether the point becomes a marker, a line, or is a move with no drawing. By combining the 4 drawing modes,any combination of moving and drawing, markers, and lines can be combined in the same plot series. The drawing mode is available only if you specify values for the first 4 arguments. If the point has no error bars, just specify 0 for their lengths.

Drawing Modes

nDrawMode	Operation
0	Draws a marker at x,y
1	Moves to x,y (draws nothing).
2	Draws a line to x,y starting from the prior point.
3	Draws a marker at x,y and draws a line to x,y starting from the prior point.

Example

The following script adds points and draws them in a CPlotView. The drawing mode (5th argument) is not used.

V = CPlotView:new()	-- create a CPlotView, but not a window
V:Add(25,66.5)	-- add a point
i = V:Add(31,94.5,1.62)	-- add a point with a y error bar, get index
Printf("index = %d",i)	-- result: index = 2
V:Add(44,100.5,1.5,2.22)	-- add a point with x and y error bars
...	-- add 97 more points
V:PlotPoints()	-- plot in a new window (use () for default labels)
n = V:CountSeriesPoints()	-- the number of points in the series
Printf( "n=%d", n)	-- result: n = 100