Question

我需要在以下R代码中绘制函数（f2）中定义的圆形密度

library(circular)
mu=c(1,1.166) # true values of the mean vector of bivariate normal variables
var.1 =1.096# sigma.1.squared for first normal variable
var.2=1#sigma.2.squared of second normal variable
cov.1.2=-0.31 # covariance between the two normal variables
var.cov<-matrix(c(var.1,cov.1.2,cov.1.2,var.2),nrow=2,ncol=2,byrow=T) #variance covariance matrix of the bivariate normal random variables    
f2=function(x){
  u=cbind(cos(x),sin(x))
  a=drop((u)%*%solve(var.cov)%*%t(u))
  b=drop((u)%*%solve(var.cov)%*%(mu))
  c=drop(-0.5*t(mu)%*%solve(var.cov)%*%mu)
  d=drop(b/sqrt(a))
  aa=(cos(x))*(1/(2*pi*a*sqrt(det(var.cov))))*exp(c)*(1+((d*pnorm(d))/dnorm(d)))
  return(aa)
}
curve.circular(f2,from=0,to=2*pi,n=101)

问题是我收到错误消息：

lines.circular（x，y，...）中的错误：找不到对象'll' 另外：警告消息：在sqrt（a）中：产生了NaNs

我不知道该如何处理该错误

使用curve.circular绘制圆密度

0 个答案: