R help - Feb 2004 - In praise of ->

This is not a problem, but I thought that I might say one or two things 
in favour of right pointing assignment before anybody influential gets 
the idea of scrapping it!

Situation (a)

You have just typed a long complcated expression into the console and 
you suddenly realise that you will need it later in the session. Just 
append
-> something
to the end of the expression. You can do this with any recently 
evaluated expression with the help of the up-arrow key (in Windows at 
least).

Situation (b)

You have written a chunk of code and you want to see how it behaves for 
various values of the scalar "fred". Just put
-> fred
at the start of the code block, type any number, then paste the code 
into the console.

Cheers,  Murray

-- 
Dr Murray Jorgensen      http://www.stats.waikato.ac.nz/Staff/maj.html
Department of Statistics, University of Waikato, Hamilton, New Zealand
Email: maj at waikato.ac.nz                                Fax 7 838 4155
Phone  +64 7 838 4773 wk    +64 7 849 6486 home    Mobile 021 1395 862

> From: Murray Jorgensen
> 
> This is not a problem, but I thought that I might say one or 
> two things 
> in favour of right pointing assignment before anybody 
> influential gets 
> the idea of scrapping it!
> 
> Situation (a)
> 
> You have just typed a long complcated expression into the console and 
> you suddenly realise that you will need it later in the session. Just 
> append
> -> something
> to the end of the expression. You can do this with any recently 
> evaluated expression with the help of the up-arrow key (in Windows at 
> least).
You can do this just as easily in two ways:

1. IforgotThis <- .Last.value   [This always works, even if command editing
is not available.]

2. If command line editing is available, hit [up-arrow], [home] (or ctrl-a)
then type IforgotThis = ...
 
> Situation (b)
> 
> You have written a chunk of code and you want to see how it 
> behaves for 
> various values of the scalar "fred". Just put
> -> fred
> at the start of the code block, type any number, then paste the code 
> into the console.
This is also easily accomodated w/o the use of ->:  Instead of 

MyValue -> fred
[code that follows]

use:

fred <-
MyValue
[code that follows]

Andy

 
> Cheers,  Murray
> 
> -- 
> Dr Murray Jorgensen      http://www.stats.waikato.ac.nz/Staff/maj.html
> Department of Statistics, University of Waikato, Hamilton, New Zealand
> Email: maj at waikato.ac.nz                                Fax 7 838 4155
> Phone  +64 7 838 4773 wk    +64 7 849 6486 home    Mobile 021 1395 862
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://www.stat.math.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide! 
> http://www.R-project.org/posting-guide.html
> 
> 

------------------------------------------------------------------------------
Notice:  This e-mail message, together with any attachments,...{{dropped}}

Liaw, Andy wrote:


 > This is also easily accomodated w/o the use of ->:  Instead of
 >
 > MyValue -> fred
 > [code that follows]
 >
 > use:
 >
 > fred <-
 > MyValue
 > [code that follows]
 >
 > Andy

The point is that

-> fred
[code that follows]

is sitting as one piece in the clipboard. So instead of

3 <paste>
8 <paste>
etc

you need to do

fred -> 3 <paste>
fred -> 8 <paste>
etc

Not a big saving, but some of us are lazy!


-- 
Dr Murray Jorgensen      http://www.stats.waikato.ac.nz/Staff/maj.html
Department of Statistics, University of Waikato, Hamilton, New Zealand
Email: maj at waikato.ac.nz                                Fax 7 838 4155
Phone  +64 7 838 4773 wk    +64 7 849 6486 home    Mobile 021 1395 862