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一些背景资料:我需要在3D网格从某点的距离计算出到每个小区,则应用一个函数这个距离。我需要为多个点执行此操作,并为所有点在每个单元格中添加函数值。我可以使用下面的代码为位于(x,Y,Z)的点做到这一点:řforeach循环三维阵列数据
x <- c(1,2,3,4,5)
y <- x
z <- x
radius <- c(0.4,0.5,0.6,0.7,0.8)
numsphere <- length(x)
radius_buffer <- 0.2
xvox <- seq((min(x)-1),(max(x)+2),0.5)
yvox <- xvox
zvox <- xvox
probability_array <<- array(0,dim=c(length(xvox),length(yvox),length(zvox)))
for (j in 1:length(yvox)){ # for every y element
for (i in 1:length(xvox)){ # for every x element
for (k in length(zvox):1){ # for every z element
for (n in 1:numsphere){ # for the total number of points
dist_sd <- ((xvox[i]-x[n])^2+(yvox[j]-y[n])^2+(zvox[k]-z[n])^2)^0.5
probability_array[i,j,k] <- probability_array[i,j,k] +
round(exp(-1*(dist_sd-radius[n])^2/(2*radius_buffer^2)),3)
}
}
}
}
输出是一个数组,所标绘的结果如下所示:
probability_array <- probability_array/max(probability_array)
contour3d(probability_array,level=c(0.2,0.8,0.9),x=xvox,y=yvox,z=zvox,color = c("aquamarine","gold","darkorange"),alpha = c(0.1,0.2,0.5),add=T)
我试图平行这个,因为它似乎是理想的,但不能得到它的工作。 我已经试过:
cl<-makeCluster(detectCores(),type="SOCK")
registerDoSNOW(cl)
for (j in 1:length(yvox)){
for (i in 1:length(xvox)){
for(k in length(zvox):1){
probability_array[i,j,k] <- foreach(n=1:numsphere, .combine='+') %dopar% {
dist_sd <- ((xvox[i]-x[n])^2+(yvox[j]-y[n])^2+(zvox[k]-z[n])^2)^0.5
round(exp(-1*(dist_sd-radius[n])^2/(2*radius_buffer^2)),3)
}
}
}
}
之类的东西:
r <- foreach(j=1:length(yvox)) %:% foreach(i=1:length(xvox)) %:% foreach(k=length(zvox):1) %:% foreach(n=1:numsphere, .combine='+') %do% {
dist_sd <- ((xvox[i]-x[n])^2+(yvox[j]-y[n])^2+(zvox[k]-z[n])^2)^0.5
probability_array[i,j,k] <- probability_array[i,j,k] + round(exp(-1*(dist_sd-radius[n])^2/(2*radius_buffer^2)),3)
probability_array[i,j,k]
}
但我失去了一些重要的东西。任何帮助将不胜感激。 干杯
冠军!我不知道这是可能的。四舍五入,我错过了。非常感谢你。 – Mark