R在不规则网格上的水平图

Question

我想在R中创建一个2D水平图，其中x和y坐标来自不规则网格，而不使用插值。 网格如下：

grid<-cbind(seq(from=0.05,to=0.5,by=0.05),seq(from=0.05,to=0.5,by=0.05))
grid<-rbind(grid,cbind(seq(from=0.0,to=0.95,by=0.05),seq    (from=0.05,to=1,by=0.05)))
grid<-rbind(grid,cbind(seq(from=0,to=0.9,by=0.05),seq (from=0.1,to=1,by=0.05)))
grid<-rbind(grid,cbind(seq(from=0,to=0.85,by=0.05),seq(from=0.15,to=1,by=0.05)))
grid<-rbind(grid,cbind(seq(from=0,to=0.75,by=0.05),seq(from=0.25,to=1,by=0.05)))
grid<-rbind(grid,cbind(seq(from=0,to=0.80,by=0.05),seq(from=0.20,to=1,by=0.05)))
grid<-rbind(grid,cbind(seq(from=0,to=0.70,by=0.05),seq(from=0.30,to=1,by=0.05)))
grid<-rbind(grid,cbind(seq(from=0,to=0.65,by=0.05),seq(from=0.35,to=1,by=0.05)))
grid<-rbind(grid,cbind(seq(from=0,to=0.60,by=0.05),seq(from=0.40,to=1,by=0.05)))
grid<-rbind(grid,cbind(seq(from=0,to=0.55,by=0.05),seq(from=0.45,to=1,by=0.05)))
grid<-rbind(grid,cbind(seq(from=0,to=0.50,by=0.05),seq(from=0.50,to=1,by=0.05)))
grid<-rbind(grid,cbind(seq(from=0,to=0.40,by=0.05),seq(from=0.60,to=1,by=0.05)))
grid<-rbind(grid,cbind(seq(from=0,to=0.45,by=0.05),seq(from=0.55,to=1,by=0.05)))
grid<-rbind(grid,cbind(seq(from=0,to=.35,by=0.05),seq(from=0.65,to=1,by=0.05)))
grid<-rbind(grid,cbind(seq(from=0,to=0.30,by=0.05),seq(from=0.70,to=1,by=0.05)))
x=grid[,1]
y=grid[,2]

Z值存储在另一个向量中。 我试图使用图像功能，但是没有任何运气。 例如，如果我尝试

image(x,y,height.vals)

哪里

    height.vals=matrix(runif(dim(grid)[1]),nrow=dim(grid)[1],ncol=1)

我收到一条错误消息，说x和y应该增加。

一个人可以使用akima函数interp，但是随后我得到了插值数据。

Answer 1

看起来您在20 x 20的网格上有点。 因此，您可以创建20 x 20的矩阵，并用height.vals的值填充它。

稍作调整，就可以将x和y值转换为矩阵的索引，并使用这些索引将height.vals分配给height.vals中的适当位置。

# Turn the x and y values into integers.
# R doesn't take 0 as an index, so add 1 to the x values to get rid of the 0s
inds <- cbind(x = as.integer(20*x + 1), y = as.integer(20*y))

# create the 20 x 20 matrix
m <- matrix(nrow = 20, ncol = 20)
# fill the matrix with height.vals based on the indices
m[inds] <- height.vals

然后，您可以将m用作image ， filled.contour和lattice::levelplot类的函数的输入

image(m)