CALL SYMBOL(X,Y,DIA,ISYMB) -- This routine plots a symbol at the specified location. X,Y - Location of the point in scale inches. DIA - Diameter of the symbol in scale inches. ISYMB - Symbol type. = -4, Error symbol, "I" = -3, Plus sign = -2, Times sign = -1, Vertical line, (symbol for SPCTR) = 0, No symbol = 1, Square = 9, Baseball Diamond = 2, Circle = 10, House = 3, Triangle, point up = 11, Triangle, point down = 4, Star, five pointed = 12, Diamond, lying down = 5, Diamond, square = 13, Club = 6, Quarter circle = 14, Heart = 7, Tunnel = 15, Spade = 8, Diamond = 16, Three-leafed clover Adding 16 to ISYMB will generate a centered dot; adding 32, a centered plus sign; adding 48 will fill in the symbol.