• editor: type & save code for reuse later
• console: basic interaction w/ R & type code

R Markdown

• allows put code, outputs, comments
• need a code chunk

```{r}
# the code need to run and out put
## do not forget output-function to show the results

example:

x <- 4+3
x

![Untitled](<https://s3-us-west-2.amazonaws.com/secure.notion-static.com/42f277cf-bd4b-4124-be81-0141807acb77/Untitled.png>)

---

- related to LaTex for output math formula

```r
\\[
\\bar{X}
\\]

• use Kint to output as HTML/PDF

• when commentting, comment the code in code chunk (for hw)
• use "=" instead of "←" is discouraged