r - R 中使用 persp3d 图实现 Ackley 函数

Question

x1<-as.matrix(seq(-32.768,32.768,length=100))

x2<-as.matrix(seq(-32.768,32.768,length=100))

X<-cbind(x1,x2)

y <- outer(X,X,Ackley)

功能实现

Ackley <- function(x1,x2){
a<-20
b<- 0.2
c<-(2*pi)

fofx1<- -a*exp(-b*sqrt((rowSums(X^2)/100)))-
exp(rowSums(cos((c*X)/100)))+a+exp(1)

fofx2 <- -a*exp(-b*sqrt((rowSums(X^2)/100)))-
exp(rowSums(cos((c*X)/100)))+a+exp(1)
return(fofx1+fofx2)
}

我收到这样的错误 -dim(robj) <- c(dX, dY) 中的错误: dims [产品 40000] 与对象的长度 [100] 不匹配

我不会这样绘制

Answer 1

ackley <- function(x1, x2) {
 a <- 20
 b <- 0.2
 c <- (2*pi)
 d <- 2
 fofx1 <- -a*exp(-b*sqrt(1/d*sum(c(x1,x2)^2))) -
           exp(sum( cos(c*c(x1,x2))/d))+a+exp(1)

 #fofx2 <- -a*exp(-b*sqrt(sum(c(x1,x2)^2)/100))-
 #          exp(sum( cos(c*c(x1,x2))/100))+a+exp(1)
 return(fofx1)
}
Ackley <- Vectorize(ackley)

x1 <- seq(-32.768,32.768,length=500)
x2 <- seq(-32.768,32.768,length=500)
z <- outer(x1, x2, FUN="Ackley")

library(plotly)
plot_ly(x=~x1, y=~x2, z = ~z, type="surface") %>% 
 layout(scene=list(aspectratio = list(x = 1, y = 1, z = 1)))