平滑点的曲线，并在R中包含原点

Question

I am a beginner in R and started with graphics recently.

I have managed to program a working empirical cumulative distribution function (user-generated, not using the standard ecdf() function) and to generate a plot. However, the plot is not as it should be, there are two issues with it and I am not sure on how to solve them (I have done my 'research' but have not found a solution).

This is my code:

set.seed(1)
n = 50

x = rpois(n, 2.2)

cdf = function(x,n)
{
  v=c()
  for(z in 1:max(x))
  {
    a = length(x[x<=z])/n
    v = c(v, a)
  }
  plot(v,type="l", main="empirical cumulative distribution function",   xlab="x", ylab="cumulative probability", xlim=c(0,6), ylim=c(0,1.0))

}
cdf(x, n)

There are two issues with this plot:

1. The lines are straight but it should be a smooth curve through all points.

2. The origin is not included (now the curve starts at x = 1).

How can these issues be resolved in an elegant way?

Answer 1

尝试使用以下样条插值器：

plot(spline(c(0, v)), type = "l")