Using org-table data for R block

Question

I'd like to be able to plot in an orgbabel chunk these data I have in a org-table:

#+NAME:amount
| date             | amount
|------------------+--------|
| <2022-01-30 Sun> |   55.1 | 
| <2022-01-31 Mon> |   54.7 |
| <2022-02-01 Tue> |   54.5 |
| <2022-02-02 Wed> |   55.1 |
| <2022-02-03 Thu> |   54.2 |
| <2022-02-04 Fri> |   54.1 |
| <2022-02-05 Sat> |   53.9 |
| <2022-02-06 Sun> |   54.1 |

The idea is to use these data in a R block and plot amount (y axis) as a function of date (x axis):

#+BEGIN_SRC R 
#+END_SRC

How to reference the data?

Thanks!

Answer 1

You can pass the table name to a variable in the R block header:

#+NAME:amount
| date             | amount
|------------------+--------|
| <2022-01-30 Sun> |   55.1 | 
| <2022-01-31 Mon> |   54.7 |
| <2022-02-01 Tue> |   54.5 |
| <2022-02-02 Wed> |   55.1 |
| <2022-02-03 Thu> |   54.2 |
| <2022-02-04 Fri> |   54.1 |
| <2022-02-05 Sat> |   53.9 |
| <2022-02-06 Sun> |   54.1 |


#+begin_src R :var tab=amount
  tab[, 2] <-tab[, 2] * 100
  tab
#+end_src

#+RESULTS:
| <2022-01-30 Sun> | 5510 |
| <2022-01-31 Mon> | 5470 |
| <2022-02-01 Tue> | 5450 |
| <2022-02-02 Wed> | 5510 |
| <2022-02-03 Thu> | 5420 |
| <2022-02-04 Fri> | 5410 |
| <2022-02-05 Sat> | 5390 |
| <2022-02-06 Sun> | 5410 |

Note that your orgmode time stamps will be imported as character strings. If you want to use them as dates, you'll need to convert them in R, maybe with lubridate or something similar.

Update

Working with dates in R is a big topic, and off-topic here. Here's a pointer for converting org timestamps to Date objects:

#+begin_src R :var tab=amount
  tab[, 1] <- as.Date(tab[, 1], tryFormats = "<%Y-%m-%d")
  plot(tab)
#+end_src