To provide a polygon creation method for a geographical information system and its device capable of creating a polygon by reducing a calculation processing amount until display is executed after display instruction.
This polygon creation method for a geographical information system is so structured that a plurality of peak coordinates constituting a display object house frame stored in geographical data are read; a first line segment connecting the i-th peak of the peak coordinates to the (i+1)-th peak adjacent to it is found; then a second line segment connecting the (i+1)-th peak to the (i+2)-the peak is found; an angle difference formed by the second line segment with respect to the first line segment is found; when the angle difference is smaller than a predetermined value, processes for deleting the (i+1)-th peak coordinates are repeated for line segments sequentially formed by all the peak coordinates; and the polygon is created based on the peak coordinates not deleted.
SATO TOKUSHI
MUTO HIROMICHI
| JP2001256231A | 2001-09-21 | |||
| JPH0869525A | 1996-03-12 | |||
| JPH11213128A | 1999-08-06 | |||
| JPH11120332A | 1999-04-30 | |||
| JPH09185700A | 1997-07-15 |