R help - May 2010 - export dataframe's column classes to a list

Hi Folks,

I want to export a dataframe's column classes to a list so that I can
reinstantiate the dataframe from a CSV file in the future.  (I know
about save(), which I'm using in addition to this).

what I want to do is the following:
    write.csv(myframe);
    col_classes = get_col_classes(myframe);
    write.csv(col_classes, "column_classes")

    ... time passes, R gets closed, etc ...

    col_classes = read.csv("column_classes")
    new_myframe = read.csv("myfile.csv", colClasses = col_classes)


My question is how to construct the "get_col_classes()" function
above.
 Any thoughts are greatly appreciated!

Thanks,
Allie

-- 
Alexander Shenkin
PhD Candidate
School of Natural Resources and Environment
University of Florida

http://snre.ufl.edu/people/students.asp

Tena koe Allie

Does

sapply(myframe, class)

do what you want?

Peter Alspach
> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> project.org] On Behalf Of Alexander Shenkin
> Sent: Thursday, 20 May 2010 8:19 a.m.
> To: r-help at r-project.org
> Subject: [R] export dataframe's column classes to a list
> 
> Hi Folks,
> 
> I want to export a dataframe's column classes to a list so that I can
> reinstantiate the dataframe from a CSV file in the future.  (I know
> about save(), which I'm using in addition to this).
> 
> what I want to do is the following:
>     write.csv(myframe);
>     col_classes = get_col_classes(myframe);
>     write.csv(col_classes, "column_classes")
> 
>     ... time passes, R gets closed, etc ...
> 
>     col_classes = read.csv("column_classes")
>     new_myframe = read.csv("myfile.csv", colClasses =
col_classes)
> 
> 
> My question is how to construct the "get_col_classes()" function
above.
>  Any thoughts are greatly appreciated!
> 
> Thanks,
> Allie
> 
> --
> Alexander Shenkin
> PhD Candidate
> School of Natural Resources and Environment
> University of Florida
> 
> http://snre.ufl.edu/people/students.asp
> 
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