There are two examples for batching jobs in the page.
The first one will demonstrate different batching method, and
the second will demonstrate a batching method with extra arguments.
Some of Linux knowledges are required for understanding these commands,
and they are also useful when you have to process bunch of jobs.
More ways to batch jobs can be found at the page
"Batch More"
in this web site
and the page
"Rscript"
in the
HPSC
web site.
---
#### Example 1:
1. For MS Windows user
Use Rterm.exe
or Rcmd.exe
to substitute
R
in the following command mode.
2. Hello world !
First, create an R code file "hello_1.r" contains the following.
```
# File name: hello_1.r
a <- c("Hello", "world", "!")
print(a)
b <- paste(a, collapse = " ")
print(b)
```
Here, it sets an array variable "a" contains 3 elements, "Hello", "world", and "!", and
prints them. It also uses the function "paste" to join all elements in array "a" by " " (space)
and then it sets the array to a variable "b" and prints it.
3. Batch From Script
Use the command mode to send "hello_1.r" as a batch job.
```
SHELL> R CMD BATCH --vanilla --slave hello_1.r output_file
```
or
```
SHELL> nohup R CMD BATCH --vanilla --slave hello_1.r output_file &
```
By default, the output will be saved in "hello_1.r.Rout" if an "output_file" isn't
assigned. The output file (hello_1.r.Rout) will as the following.
```
> a <- c("Hello", "world", "!")
> print(a)
[1] "Hello" "world" "!"
> b <- paste(a, collapse = " ")
> print(b)
[1] "Hello world !"
>
```
4. Batch From Command
Use the command mode to send "hello_1.r" as a batch job from [STDIN] and show the
output on [SDTOUT]. The followings have similar commands, and can provide
same results, but they can be used in different purposes.
```
SHELL> R --vanilla --slave < hello_1.r > output_file
```
or
```
SHELL> cat hello_1.r | R --vanilla --slave > output_file
```
or
```
SHELL> echo 'source("hello_1.r")' | R --vanilla --slave > output_file
```
By default, the output will be show on the screen, you can use ">" to redirect the
output into "output_file". The output will like this.
```
[1] "Hello" "world" "!"
[1] "Hello world !"
```
---
#### Example 2:
1. Hello world, MOLAS !
First, create an R code file "hello_2.r" contains the following.
```
# File name: hello_2.r
a <- c("Hello", "world,", argv, "!")
print(a)
b <- paste(a, collapse = " ")
print(b)
```
Here, it sets an array variable "a" contains 4 elements, "Hello", "world,", argv,
and "!", and prints them. The variable "argv" will be passed from STDIN command.
It also uses the function "paste" to join all elements in array "a" by " " (space)
and sets to a variable "b" and prints it.
2. Pass Variable From STDIN
Use command mode to send "hello_2.r" for batch job from STDIN and show the
output on SDTOUT. The variable "argv" as "MOLAS" is assigned before the "hello_2.r" is passed to R.
```
SHELL> echo 'argv <- "MOLAS"; source("hello_2.r")' | R --vanilla --slave > output_file
```
By default, the output will be shown on the screen, you can use ">" to redirect the
output into an "output_file". The output will like this.
```
[1] "Hello" "world," "MOLAS" "!"
[1] "Hello world, MOLAS !"
```
3. Background process in Linux
The commends may include `echo`, `nohup`, `&`, `|`, `<`, and `>`.
---