r - insert side by side png images using knitr

Question

How can I insert side by side png files from my computer into rstudio when creating an html document?

The following works well (plots)

```{r, echo=FALSE,fig.width=4, fig.show='hold'}
 plot(cars)
plot(rnorm(100))
```

But for images from a path, only the last image is displayed

 ```{r fig.width=3, fig.show='hold'}
   library(png)
  img <- readPNG("C:/path to my picture/picture.png")
  grid.raster(img)

  img2 <- readPNG("C:/path to my picture/picture2.png")
  grid.raster(img2)
  ```

Answer 1

You can use knitr::include_graphics() as this one accepts a vector of paths as an argument.

Then you should use fig.show='hold',fig.align='center' in order to plot them on the same line and out.width="49%", out.height="20%" to control the output size.

```{r, echo=FALSE,out.width="49%", 
out.height="20%",fig.cap="caption",fig.show='hold',fig.align='center'}
knitr::include_graphics(c("path/to/img1","path/to/img1"))
```