[R] Converting a list to a data frame

[Rui Barradas]

Hello,

No, it's not possible to work with a matrix in ggplot2.
Not even with an object of class "list".



l <- list(x=1:5, y=1:5)
d <- as.data.frame(l)
m <- as.matrix(d)

library(ggplot2)
ggplot(l, aes(x, y)) + geom_point()  # Error
ggplot(d, aes(x, y)) + geom_point()  # OK, as expected
ggplot(m, aes(x, y)) + geom_point()  # Error



Hope this helps,

Rui Barradas


Às 22:31 de 24/07/21, Jeff Reichman escreveu:
> Duncan
> 
> I need to plot the results (ggplot2) and I'm thinking I can only use a data.frame object in ggplot2. It is a rath r large "list" over 1 million rows. It is possible to work with a matrix in ggplot2?
> 
> Jeff
> 
> -----Original Message-----
> From: Duncan Murdoch <murdoch.duncan using gmail.com>
> Sent: Saturday, July 24, 2021 12:03 PM
> To: reichmanj using sbcglobal.net; R-help using r-project.org
> Subject: Re: [R] Converting a list to a data frame
> 
> Others have shown you how to extract the matrix and convert it to a dataframe.  My only addition is to suggest that you don't do this:
> matrix methods are often much more efficient than dataframe methods, so if you can work with the matrix without conversion, you'll often find things run a lot faster.
> 
> Duncan Murdoch
> 
> On 24/07/2021 9:18 a.m., Jeff Reichman wrote:
>> How does one convert a list into a data frame?
>>
>>    
>>
>>> str(weight_chains)
>>
>> List of 1
>>
>> $ : 'mcmc' num [1:100000, 1:3] -105 -105 -105 -104 -103 ...
>>
>>     ..- attr(*, "dimnames")=List of 2
>>
>>     .. ..$ : NULL
>>
>>     .. ..$ : chr [1:3] "a" "b" "s"
>>
>>     ..- attr(*, "mcpar")= num [1:3] 1001 101000 1
>>
>> - attr(*, "class")= chr "mcmc.list"
>>
>>    
>>
>> Such that ..
>>
>>    
>>
>>>
>>
>> weight_chains
>>
>>
>>
>>                  a         b         s
>>
>> 1     -104.72512 1.0141407  9.369227
>>
>> 2     -104.52297 1.0167432  9.131354
>>
>> 3     -104.72669 1.0139528  9.219877
>>
>>    
>>
>>
>> 	[[alternative HTML version deleted]]
>>
>> ______________________________________________
>> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide
>> http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>>
> 
> ______________________________________________
> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>