PGPLOT Module: PGOLIN -- mark a set of points using the cursor


SUBROUTINE PGOLIN (MAXPT, NPT, X, Y, SYMBOL)
INTEGER MAXPT, NPT
REAL X(*), Y(*)
INTEGER SYMBOL

Interactive routine for user to enter data points by use of
the cursor. Routine allows user to Add and Delete points. The
points are returned in the order that they were entered (unlike
PGNCUR).


Arguments
MAXPT (input) : maximum number of points that may be accepted.
NPT (in/out) : number of points entered; should be zero on
first call.
X (in/out) : array of x-coordinates.
Y (in/out) : array of y-coordinates.
SYMBOL (input) : code number of symbol to use for marking
entered points (see PGPT).

Note (1): The dimension of arrays X and Y must be greater than or
equal to MAXPT.

Note (2): On return from the program, cursor points are returned in
the order they were entered. Routine may be (re-)called with points
already defined in X,Y (number in NPT), and they will be plotted
first, before editing.

Note (3): User commands: the user types single-character commands
after positioning the cursor: the following are accepted:
A (Add) - add point at current cursor location.
D (Delete) - delete the last point entered.
X (eXit) - leave subroutine.