polygons是什么意思
时间: 2024-08-30 12:02:15 浏览: 122
polygons是指几何学中的一个多边形,它是由三个或更多直线段连接而成的封闭图形,每条线段称为边,相邻边之间的交点称为顶点。常见的多边形有三角形、四边形(如正方形、矩形)、五边形等。在计算机图形学、游戏开发以及数学分析等领域中,多边形被广泛用于表示和操作二维或三维空间中的形状。它们是基础的数据结构,用于描述复杂的几何形状。
相关问题
polygons具体是什么类
`polygons` 是一个列表,其中包含多边形的顶点坐标。每个多边形是一个由顶点坐标组成的列表,例如:
```java
List<double[]> polygons = new ArrayList<>();
double[] polygon1 = new double[]{116.395, 39.910};
double[] polygon2 = new double[]{116.394, 39.914};
double[] polygon3 = new double[]{116.403, 39.920};
double[] polygon4 = new double[]{116.410, 39.907};
polygons.add(polygon1);
polygons.add(polygon2);
polygons.add(polygon3);
polygons.add(polygon4);
```
这里表示一个由四个顶点组成的多边形,每个顶点坐标为一个长度为2的数组,分别表示经度和纬度。在实际使用中,可以根据需要修改顶点坐标的数据类型和数据结构。
R code for dissolved overlapping polygons and retained larger areas for polygons
Here's an example using the `sf` package in R:
```R
library(sf)
# Create example polygons
poly1 <- st_polygon(list(rbind(c(0,0), c(0,1), c(1,1), c(1,0), c(0,0))))
poly2 <- st_polygon(list(rbind(c(0.5,0.5), c(0.5,1.5), c(1.5,1.5), c(1.5,0.5), c(0.5,0.5))))
polys <- st_as_sf(data.frame(id = c(1,2), geometry = st_sfc(poly1, poly2)))
# Dissolve overlapping polygons and retain larger areas
polys_dissolved <- st_union(polys)
polys_largest <- polys_dissolved[which.max(st_area(polys_dissolved)), ]
```
In this example, we first create two polygons (`poly1` and `poly2`) that overlap. We then combine them into a single `sf` object (`polys`) and use the `st_union()` function to dissolve the overlapping polygons. Finally, we use `which.max()` to find the largest area polygon in the resulting object (`polys_dissolved`) and assign it to `polys_largest`.
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