仅在R图中显示轴的一部分

背景：如下图所示，当前y轴从-2延伸到2，即y轴包含正值和负值

问题:

保持一切如下图所示，我想知道是否有一种方法可以从0开始只显示y轴的正部分，并以某种方式隐藏y轴的负部分？请参阅下面的R代码

以下是R代码：

看到了吗？轴。您只需要指定at参数

axisside=2，at=0:2

if(!require(library(plotrix))){install.packages('plotrix') }
library(plotrix)          ## A package for drawing ellipses ##


plot(1, ty='n', ann = F, axes = F, xlim = c(-4, 6), ylim = c(-2.5, 2) ) ## platform for ellipses

axis(side = 2)   ## HERE is my question ## ???


draw.ellipse(x = rep(1, 11), y = rep(-1.2, 11), 
     a = seq(1, 6, by = .4), b = seq(1/4.5, 6/4.5 , by = .4/4.5 ), 
     lty = 2, border = 'gray60' )       ## Draw multiple Concentric ellipses ##


AA <- seq(-4, 6, len = 13)     ## A range of values on the x-xis just like "xlim" ##
BB <- dcauchy( AA, 1, .95)*5   ## The Height for the AA according to a distribution ##

segments(AA, rep(-1.2, length(AA) ), AA, BB, lty = 3, lwd = 2, col= 'green4' )

curve(dcauchy(x, 1, .95)*5, -4, 6, add = T, col ='magenta', lwd = 3)