Entire Results from R

msanchez78 has asked for the wisdom of the Perl Monks concerning the following question:

seeking the wisdom of the perl monks ...

within R i submit this code:

> data <- c("2016-03-15 13","2016-03-16 23","2016-03-17 06","2016-03-1
+8 15","2016-03-19 08","2016-03-20 21")
> datevec <- strptime(data,"%Y-%m-%d %H")
> difftime(datevec[-length(datevec)],datevec[-1],units="hours")
[download]

which correctly produces this output:
Time differences in hours
1 -34 -7 -33 -17 -37

notice the two lines. now, in perl i have this code:

$R->set( 'data', "2016-03-15 13","2016-03-16 23","2016-03-17 06","2016
+-03-18 15","2016-03-19 08","2016-03-20 21" );
$R->run( q`datevec <- strptime(data,"%Y-%m-%d %H")` );
$R->run( q`xx <- difftime(datevec[-length(datevec)],datevec[-1],units=
+"hours")` );
@Rres = $R->get('xx');
print Dumper(\@Rres);
[download]

which correctly produces this result:

$VAR1 = [
          [
            'Time',
            'difference',
            'of',
            'hours'
          ]
        ];
[download]

the problem is that no matter what i do i cannot get to the second output line from R ... the line 1 -34 -7 -33 -17 -37

any suggestion on how i can get to the second (and in many cases n-number) of subsequent output lines from R? thanks!

Comment on Entire Results from R Select or Download Code

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Re: Entire Results from R by Veltro (Hermit) on Feb 20, 2019 at 16:31 UTC
Can you try to print the raw result? Maybe this will help to see what is wrong. my $tmp_str = $R->run(qq`print($varname)`); print $tmp_str . "\n" ; [download] I got the previous line from the 'get' method of the module Statistics::R which I assume you are using. The 'get' method is doing a whole bunch of other stuff (which may cause the problem), so this line might show the entire result. Another small thing is that you are using `@Rres = $R->get('xx');` and the method is returning a array reference. Although it is not entirely incorrect I do suggest using `my $Rres = $R->get('xx'); print Dumper($Rres);` instead Further I don't know much about R edit: Oh, and $varname should be 'datevec' or 'xx' or in this case of course.	[reply] [d/l] [select]
Re^2: Entire Results from R by msanchez78 (Initiate) on Feb 20, 2019 at 18:49 UTC
hi ... thank you for your prompt reply. i tried my $tmp_str = $R->run(qq`print($varname)`); print $tmp_str . "\n" ; [download] the result is the same --- the first line only: Time difference of hours yikes!	[reply] [d/l]
Re^3: Entire Results from R by Your Mother (Archbishop) on Feb 20, 2019 at 22:13 UTC
I would go in and manually edit this line to `1`– `use constant DEBUG => 0; # debugging messages` [download] And see what you get.	[reply] [d/l] [select]
Re: Entire Results from R by haukex (Archbishop) on Feb 21, 2019 at 09:14 UTC
Your use of `$R->set()` is incorrect: to set multiple values, you have to pass an arrayref: `$R->set( 'data', ["2016-03-15 13","2016-03-16 23","2016-03-17 06","2016-03-18 15","2016-03-19 08","2016-03-20 21"] );` Then the code works for me.	[reply] [d/l] [select]
Re^2: Entire Results from R by kevbot (Priest) on Feb 22, 2019 at 06:36 UTC
++haukex I put together a short script to confirm that your solution works (I was curious about Statistics::R since I had not used it before). This code, #!/usr/bin/env perl use Statistics::R; use Data::Dumper; # Create a communication bridge with R and start R my $R = Statistics::R->new(); $R->set( 'data', [ "2016-03-15 13", "2016-03-16 23", "2016-03-17 06", "2016-03-18 15", "2016-03-19 08", "2016-03-20 21" ] ); $R->run( q`datevec <- strptime(data,"%Y-%m-%d %H")` ); $R->run( q`xx <- difftime(datevec[-length(datevec)],datevec[-1],units= +"hours")` ); @Rres = $R->get('xx'); print Dumper(\@Rres); exit; [download] Gives this output, `$VAR1 = [ [ '[1]', '-34', '-7', '-33', '-17', '-37' ] ];` [download]	[reply] [d/l] [select]
Re^3: Entire Results from R by haukex (Archbishop) on Feb 22, 2019 at 18:05 UTC
Thanks for the example! I also submitted a pull request that adds a "too many arguments" error to `->set`.	[reply] [d/l]


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