[R] Epicalc package

[David Winsemius]

On Nov 14, 2008, at 8:12 AM, Luciano La Sala wrote:

> Dear R-friends,
>
> I am using the epicalc package and the manual by V. Chongsuvivatwong  
> "Analysis of epidemiological
> data using R and Epicalc" to get the hang of some basic  
> epidemiological analyses.
>
> After running all the analyses of chapter 7, one is supposed to wrap  
> it up by saving the data writing:
>
>> save(.data, file = "Chapter7.Rdata")
>
> ... after writing the command and pressing Enter, the program just  
> asks for more input by printing out its prompt "<".

Isn't that actually indicating that the action was successful?

> Q: what am I supposed to do next?

? Perhaps you are presumed to need some rest and quitting would be  
appropriate. Try quit()

> Where would the data be saved and in what format?

It is saved in the working directory in .Rdata format

> Can one retrieve it later?

That is what load() does for you. As the next chapter implies.

>
>
> ... then chapter 8 starts by loading the data saved from the  
> preceding chapter, writing:
>
>> zap()
>> load("Chapter7.Rdata")
>
> ... but, as I told you above, I am not being able to even save the  
> data from chapter 7 correctly, so I guess there’s nothing to load  
> afterwards really, and I can’t go on with the rest.

I saw no evidence that saving the file was unsuccessful. What happens  
after typing the chapter 8 commands above and then entering ls() at  
the R prompt? Although it's not a base function, I am presuming that  
zap() is an epicalc function that cleared everything out. Don't you  
see that the the data objects were loaded back into memory?

What happens when you type getwd()? Depending on your OS (which you  
have not stated) you may or may not see any files with type .Rdata in  
that directory, but it should be there. If you are in a Windoze  
variant you may need to explicitly allow Windows Explorer to display  
full file names.

Best of luck;
David Winsemius

> Any tips will be very welcome!
>
> Luciano
> Argentina