There may be collisions between variables in .GlobalEnv and variables in the 
function-call environment, and the parent of the function-call environment 
probably includes functions & other variables not available in .GlobalEnv. (If 
the function calls substitute or anything like that then the problem becomes 
even harder.) I would probably use the debugger to step into the function. If 
you want more control then create an environment that resembles what would be 
created in a function call:

env.func <- new.env(parent=environment(f))
delayedAssign(assign.env=env.func, �.) for everything you pass in
delayedAssign(assign.env=env.func, eval.env=env.func, �.) for anything that 
will take a default value
eval(envir=env.func, �.) or evalq(envir=env.func, �.) to execute parts of the 
function body or anything else

You can even coerce body(f) to a character, strip the leading �{�, and 
parse(text=�.) to break the function into expressions. That might be easier 
than copy-pasting function code.

Regards,
Jorgen Harmse.


Message: 1
Date: Tue, 19 Sep 2023 23:09:18 +0530
From: Brian Smith <briansmith199...@gmail.com>
To: r-help@r-project.org
Subject: [R] Could you manually replicate execution of a R function
Message-ID:
        <cahubdy_wr_uwtk3t2bu+emvgvkrnhw4ddvmqmq+f0rq6r3o...@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"

Hi,

I have trying to replicate a function from rugarch package manually.
Below is the calculation based on the function,

�

        [[alternative HTML version deleted]]

______________________________________________
R-help@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.

Reply via email to