DIGITIZE
If the optional variable name, codes, is entered, then this vector
will be created and a code number will be saved in this vector for
each digitized and recorded point.
what code
-----------------------
recorded point 1
marked point 2
connected point 3
When the DIGITIZE command is entered, the graphics screen will be
cleared and instructions will be displayed on the terminal screen.
First you will be asked to give names for the four digitizing pad keys.
Next, place the digitizing pad crosshair on some point of the graph
which you know the graph coordinates of and press the requested key.
Then enter the x and y graph coordinates of this point. Repeat this
process for two more points, ensuring that the third point is not
colinear with the first two points. This defines the transformation
for the graph and the angle of the axes. Now you are ready to digitize.
It is a good idea to position the crosshair on the lower left and upper
right corners and check the values there. The key that is typed
determines what action is taken at any time.
key action taken
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button 1 display the x and y values but do not save these values
button 2 display and values in the two vectors xout and yout
button 3 display, record and put a marker at the chosen point
button 4 display, record, mark and connect to the last recorded point
F write the currently recorded values to a file
/ clear the alphanumeric terminal screen
? display the menu of key choices
Q quit; the screen will be cleared