polycenter
Area and centroid of polygon
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Syntax
[A,Cx,Cy] = polycenter(x,y) [A,Cx,Cy] = polycenter(x,y,dim)
Description
[area,Cx,Cy] = polycenter(x,y) returns the area and the centroid coordinates of the polygon specified by the vertices in the vectors x and y. If x and y are matrices of the same size, then polycenter returns the centroid and area of polygons defined by the columns x and y. If x and y are arrays, polycenter returns the centroid and area of the polygons in the first non-singleton dimension of x and y.
polycenter is an extended version of polyarea.
The polygon edges must not intersect. If they do, polycenter returns the values of the difference between the clockwise encircled parts and the counterclockwise ones. As with polyarea, the absolute value is used for the area.
[area,Cx,Cy] = polycenter(x,y,dim) returns the centroid and area of the polygons specified by the vertices in the dimension dim.
Example
Create a pentagon and determine its area and center:
x0 = rand(1); y0 = rand(1); L = linspace(0,2.*pi,6); xv = cos(L)' + x0; yv = sin(L)' + y0; xv = [xv ; xv(1)]; yv = [yv ; yv(1)]; [A,cx,cy] = polycenter(xv,yv); plot(xv,yv,cx,cy,'k+') title(['Area = ' num2str(A)]), axis equal
Information
Centroid on Wikipedia
See also
About the author
Damien Garcia, Eng., Ph.D. Assistant professor, Department of radiology CRCHUM, University of Montreal Hospital Montreal, QC, Canada Damien.Garcia.REMOVE-THIS@BiomeCardio.com