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polyarea

Area of polygon

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Syntax

a = polyarea(x,y)
a = polyarea(x,y,dim)

Description

a = polyarea(x,y) returns the area of the 2-D polygon defined by the vertices in vectors x and y.

  • If x and y are vectors of the same length, then polyarea returns the scalar area of the polygon defined by x and y.

  • If x and y are matrices of the same size, then polyarea returns a row vector containing the areas of each polygon defined by the columnwise pairs in x and y.

  • If x and y are multidimensional arrays, then polyarea operates along the first dimension whose length is not equal to 1.

example

a = polyarea(x,y,dim) operates along dimension dim.

Examples

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Open Live Script

Create a set of points that define a 2-D polygon.

p = linspace(0,2.*pi,9);
x = 1.2*cos(p)';
y = 1.2*sin(p)';

Plot the polygon.

plot(x,y);
axis equal

Figure contains an axes object. The axes object contains an object of type line.

Compute the area of the polygon.

a = polyarea(x,y)
a = 
4.0729

Input Arguments

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x-coordinates, specified as a vector, matrix, or multidimensional array.

y-coordinates, specified as a vector, matrix, or multidimensional array.

Dimension to operate along, specified as a positive integer scalar.

Tips

  • The area value returned by polyarea can depend on the order of the input points.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

Version History

Introduced before R2006a

See Also

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