Fail to add a linear trend line on a barplot in R

Question

I have created a barplot using barplot and then I want to show the linear trend. I use abline but the linear trend line does not show in the figure. I wonder what the problem is. Thanks.

set.seed(100)
Mydata=rnorm(65)
Year=1950:2014
barplot(Mydata)
fit=lm(Mydata~Year)
abline(fit)

As @G5W points out, fit=lm(Mydata~I(Year-1950)). But the new problem is that the trend line is too "long". As shown in the second figure, the trend line goes beyond the barplot. Is there any advice?

Answer 1

If you can use ggplot:

library(ggplot2)    

df <- data.frame(Mydata, Year)

ggplot(df, aes(x = Year, y = Mydata)) + 
  geom_bar(stat = "identity") + 
  geom_smooth(method = "lm")

Answer 2

To expand on @bouncyball's comment, use a higher value of line width (lwd) to resemble barplot if you want.

plot(Year, Mydata, type = 'h',lwd=5,col = "grey")
abline(fit, lty =2)

EDIT

First copy this function

barplot2 <- function(x, y, lty = 1, lwd = 1, col = "grey", border = "black"){
w = ((max(x) - min(x))/length(x)) * 0.75
plot(x, y, type = 'p', pch = NA, yaxt = "n", xaxt = "n", xlab = "", ylab = "")
for (i in 1:length(x)){
x1  = x[i] - w/2
x2 = x[i] + w/2
y1 = 0
y2 = y[i]
polygon(x = c(x1,x2,x2,x1), y = c(y1,y1,y2,y2), lty = lty, lwd = lwd, col = col, border = border)
}
}

Then make the barplot

barplot2(Year,Mydata)

Then add the ablineclip from plotrix library

ablineclip(fit, x1 = min(Year), x2 = max(Year), y1 = min(Mydata), y2 = max(Mydata))