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POLYGON
[GREG2\]POLYGON [(File)Name] [/PLOT] [/VARIABLE] [/FILL [Colour]]
[/HATCH [Ipen] [Angle] [Separ] [Phase]]
If no argument and no option, it calls the interactive cursor to define
the polygon summits. Type any key to go to next summit, C to correct the
last one, D to delete it, and type E to end the polygon definition. The
last polygon side will then appear. The polygon definition may be abort-
ed by typing Q. For graphical displays, you may use the mouse buttons
for the commands. The left mouse button draws a vertex, the middle mouse
button deletes the last vertex, and the right mouse button ends the
polygon definition. After the use of the cursor, the polygon plot is
stored in the GTV metacode in a segment named POLYGON. You can delete it
with the command CLEAR SEGMENT.
If a (File)Name is given as argument, the cursor is not called. The sum-
mit coordinates are read from:
- the named ASCII file (X in column 1, Y in column 2) if no option is
present,
- the named SIC variable, if /VARIABLE is present. It can be an array
of the form:
VAR[NXY,2] Real or Double
or a structure of the form (i.e. same as output):
VAR%NXY Integer or Long
VAR%X[VAR%NXY] Real or Double
VAR%Y[VAR%NXY] Real or Double
Whereever they come from (cursor, file, or variable), the polygon values
are stored internally; they can be printed with the command
GREG2\WRITE POLYGON, and they correspond to the variables POLY%NXY (num-
ber of vertices), POLY%X and POLY%Y (the corresponding coordinates). The
currently defined POLYGON is used by the commands MEAN and MASK.
The polygon loaded by the command can directly be plotted with the fol-
lowing options:
/FILL [Colour]: the polygon is color-filled with the current pen
colour or with the specified colour (see HELP PEN /COL for possi-
bilities),
/HATCH [Ipen] [Angle] [Separ] [Phase]: the polygon is filled with par-
allel hatch lines with the specified pen (default current), with
the given angle in degrees (default 45), separation in physical
units (default 0.25 cm), and phase from 0 to 1 to displace the
lines by this fraction of the separation from a fixed reference
(default 0).
/PLOT: the polygon contours are drawn with the current pen,
For a color-filled and/or hatched and/or contoured polygon, these three
options can be combined; they will be executed in the above order.
Gildas manager
2023-06-01