I'm trying to create simple tables with R Markdown (.Rmd), using RStudio. The most customizable and easily applicable way I found is xtable package. Even though xtable should produce a table with horizontal lines by default. What I should get would be like this (or these), but what I get is this. I cannot get it with following code:
```{r,results='asis'}
library(xtable)
tTable <- xtable(head(mtcars))
print(tTable,type="html",hline.after=c(-1,0))
tTable <- xtable(lm(mpg ~ hp, data = mtcars))
print(tTable,type="html")
```
Where am I wrong?