how do you print table in knitr - r

Question

I am trying to us knitr to print data frame in table format using xtable:
```{r xtable,fig.width=10, fig.height=8, message=FALSE, results = 'asis', echo=FALSE, warning=FALSE, fig.cap='long caption', fig.scap='short',tidy=FALSE}
print(xtable(d),format="markdown")
```
This is the data frame d:
d <- structure(list(Hostname = structure(c(8L, 8L, 9L, 5L, 6L, 7L,
1L, 2L, 3L, 4L), .Label = c("db01", "db02", "farm01", "farm02",
"tom01", "tom02", "tom03", "web01", "web03"), class = "factor"),
Date = structure(c(6L, 10L, 5L, 3L, 2L, 1L, 8L, 9L, 7L, 4L
), .Label = c("10/5/2015 1:15", "10/5/2015 1:30", "10/5/2015 2:15",
"10/5/2015 4:30", "10/5/2015 8:30", "10/5/2015 8:45", "10/6/2015 8:15",
"10/6/2015 8:30", "9/11/2015 5:00", "9/11/2015 6:00"), class = "factor"),
Cpubusy = c(31L, 20L, 30L, 20L, 18L, 20L, 41L, 21L, 29L,
24L), UsedPercentMemory = c(99L, 98L, 95L, 99L, 99L, 99L,
99L, 98L, 63L, 99L)), .Names = c("Hostname", "Date", "Cpubusy",
"UsedPercentMemory"), class = "data.frame", row.names = c(NA,
-10L))
Any ideas what I am missing here?

Answer 1

Try kable from knitr. It will format the table nicely.
If you would like to use xtable try:
print(xtable(d), type="latex", comment=FALSE)

Answer 2

While Pierre’s solution works, this should ideally happen automatically. Luckily, you can use knitr hooks to make this work.
That is, given this code:
```{r}
d
```
We want knitr to automatically produce a nicely formatted table, without having to invoke a formatting function manually.
Here’s some code I’m using for that. You need to put this at the beginning of your knitr document, or in the code that’s compiling your document:
opts_chunk$set(render = function (object, ...) {
if (pander_supported(object))
pander(object, style = 'rmarkdown')
else if (isS4(object))
show(object)
else
print(object)
})
This uses pander and additionally requires a helper function, pander_supported:
library(pander)
pander_supported = function (object)
UseMethod('pander_supported')
pander_supported.default = function (object)
any(class(object) %in% sub('^pander\\.', '', methods('pander')))
pander.table = function (x, ...)
pander(`rownames<-`(rbind(x), NULL), ...)
For nicer formatting, I also use these defaults:
panderOptions('table.split.table', Inf)
panderOptions('table.alignment.default',
function (df) ifelse(sapply(df, is.numeric), 'right', 'left'))
panderOptions('table.alignment.rownames', 'left')

Answer 3

If you are rendering your knitr/rmarkdown report to HTML, you can use the function rmarkdown::paged_table().
For example:
---
title: "My report"
output: html_document
---
```{r}
library(rmarkdown)
f <- function() {
paged_table(mtcars)
}
f()
```
This .Rmd is knit into the following HTML:
Also, consider using the gt package via gt().