[R] Fast tau-estimator line does ot appear on the plot

[varin sacha]

Dear R-experts,

Here below my reproducible R code. I want to add many straight lines to a plot using "abline"
The last fit (fast Tau-estimator, color yellow) will not appear on the plot. What is going wrong ?
Many thanks for your reply.

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Y=c(2,4,5,4,3,4,2,3,56,5,4,3,4,5,6,5,4,5,34,21,12,13,12,8,9,7,43,12,19,21)
Z=c(43,2,1,2,34,4,3,4,5,30,4,5,4,3,4,5,56,6,43,21,34,19,12,11,9,34,21,23,2,19)
reg1<-lm(Z ~ Y)
plot(Y,Z)
abline(reg1, col="black")

install.packages("robustbase")
library (robustbase)
reg=lmrob(Z ~ Y, data = Dataset)
abline(reg, col="green")

install.packages("MASS")  
library(MASS)
Huber=rlm(Z ~ Y, data = Dataset)
abline(Huber,col="red")

Tukey=rlm(Z ~ Y, data = Dataset,psi=psi.bisquare)
abline(Tukey,col="purple")
 
install.packages("quantreg")
library(quantreg)
L1=rq(Z ~ Y, data = Dataset,tau=0.5)
abline(L1,col="blue")
 
install.packages("RobPer")
library(RobPer)
FastTau(Z,Y)
fast=FastTau(Z,Y)
abline(fast, col="yellow")

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