Coordinate Systems

xyscan uses 2 coordinate systems:

Local Coordinates
These are essentially the screen coordinated of the window in which the plot is displayed is performed. The units are pixel. The upper left corner of the plot defines is defined by the origin (0,0) of the plot. x coordinate increases to the right, y increases downwards. They are displayed on the top of the Coordinate Display window once a plot is loaded.
Plot Coordinates
These are the coordinate of the data points you want to scan. In order to transform local coordinates into plot coordinates, xyscan needs markers to be set along the axis. The user has to provide the position of the markers in plot coordinates.