library(ggplot2)

prices = read.csv("mieszkania.tsv", sep="\t", header=TRUE)
prices$area = prices$powierzchnia
prices$price = prices$cena
pdf("linregr2.pdf")
ggplot(prices, aes(x=area, y=price)) + geom_point() + stat_smooth(method=lm, se=FALSE)
dev.off()