Write and Load functions from an external file
Moumita Das wrote:
Hi All, Would be grateful,if anyone can answer my queries. I need to share code. For example, if I am working in C/C++, I would put some function declarations in .h files that you would include. In PHP, I would create files with the common functions in them and then "include()" them. So far, I haven't been able to figure out what the standard practice is in R. The two options are: 1. Write everything in one file. No sharing of functions. 2. Write libraries - but you *have to package it* first to use it.
What you probably want is 2: Write a *package*. Packaging it does not take ages once you have tried it ... Uwe Ligges
Neither is a good option. how you I share functions across two scripts? there is "source()" But are there any other way? For example, in python, what I do is create common functions in a separate file (say, called A), use those functions from file B by including it like I would any other library. Then when I'm ready to 'release' it, I can package the library and the script... I did find something:----- http://www.ma.hw.ac.uk/~stan/R/Rnotes.pdf<http://www.ma.hw.ac.uk/%7Estan/R/Rnotes.pdf>says :-- To create and edit functions, use the (built-in) R function edit. (As usual, type ?edit at the command prompt for details|see Section 10.) Alternatively the function source|also available via the File menu|can be used to input lengthy function denitions from an externally edited le. (The function dump will write an existing function denition to a file.) But then source() also ,not only loads but parses the file too. https://stat.ethz.ch/pipermail/r-help/2007-October/142938.html You can save one or more functions and datasets to a file (see ?save) then on starting another session attach that file (see ?attach). The process is like:--- foo <- function(x) mean(as.numeric(x), trim = 0.3) save(foo, file = "myproject/rfunctions/saved.rda") then, when starting a new session, use attach("myproject/rfunctions/saved.rda") The .rda extension on the filename is commonly used for saved R data sets but you can also have function definitions in a saved file. Are these the only ways,and the best ways,to do what I want? *-- Thanks Moumita*