C-PLOT

Scientific Graphics and Data Analysis

3.2.11. - Mode 9: Digitize from pen plotter



Mode 9, available only in 2D mode, lets you use the pen plotter as a digitizer. If possible, the digitizing site (available from Hewlett-Packard, part number 09872-60066) should be installed in the plotter to make it easy to align the pen carriage over the desired points. To digitize, position the site over the appropriate points using the plotter's front-panel controls. Press the enter control on the plotter to send a point to the computer.

The computer will first ask you to set three scaling points that will be used to translate the plotter's native coordinates to the coordinates of the plot you are digitizing. Since there are three scaling points, it is not necessary for the axes of the points being digitized to be perfectly aligned with the plotter motions. Choosing three points that are widely separated gives the least error when C-PLOT calculates the transformation factors. When setting the scaling points, move to each one using the plotter control panel and press the enter control. The computer prints out the plotter coordinates and asks you for the equivalent coordinates on your plot.

After setting the three scaling points, site each point to be digitized in turn and press the enter control on the plotter. As each point is digitized, your coordinates appear on the terminal. You don't have to type anything else at the keyboard until you are done. To finish, type ^C.

If line-control mode is on while digitizing, the pen up or down status at the time you press the enter control is stored with each point.