R - Markdown avoiding package loading messages

Question

I have been using Knitr via R-Studio, and think it is pretty neat. I have a minor issue though. When I source a file in an R-Chunk, the knitr output includes external comments as follows:

+ FALSE Loading required package: ggplot2

+ FALSE Loading required package: gridExtra

+ FALSE Loading required package: grid

+ FALSE Loading required package: VGAM

+ FALSE Loading required package: splines

+ FALSE Loading required package: stats4

+ FALSE Attaching package: 'VGAM'

+ FALSE The following object(s) are masked from 'package:stats4':

I have tried to set R-chunk options in various ways but still didn't seem to avoid the problem:

```{r echo=FALSE, cache=FALSE, results=FALSE, warning=FALSE, comment=FALSE, warning=FALSE} 

source("C:/Rscripts/source.R");

```

Is there any way to comment out these messages?

Answer 1

To avoid package loading messages, you can suppress the warnings temporarily as follows:

defaultW <- getOption("warn") 

options(warn = -1) 

YOUR CODE 

options(warn = defaultW)

You can also use the include = FALSE to exclude everything in a chunk.i.e.,

```{r include=FALSE}

install.packages("ggplot2")

```

To only suppress messages:

```{r message=FALSE}

install.packages("ggplot2")

```