I am a complete newbee in R, and I have a problem with linear trend fitting.

My data is daily financial data for around 4 years. The financial year is 260 days (5 days a week) so the total amount of data is 913.

For the simplicity, the data is only one cloumb with 913 data and with one header.

I can plot the time series data without problem. But when I try to plot linear trend with lm, I can get the error message:

"formula.default(object, env = baseenv()) : invalid formula"

And when I try to plot the linear trend with abline, I get the error message:

"Error: $ operator is invalid for atomic vectors"

My code is below. So can anyone help me draw linear trend with lm or abline? I check the web to see how lm or abline is used. Some examples used "formula" for lm and abline, but I didn't understand what kind of formula i should use.

Code:

```
SE=read.csv(file="SE1.csv",head=TRUE,sep="")
Price<-SE$Closingprice
Price.SEK<-ts(Price, start=2011)
plot(Price.SEK,main="Stockholm 30 Index from August 2011 to March 2015",lwd=1,col=4)
str(Price.SEK)
lm.01<-lm(Price.SEK)
```