Re: [R] Trying to understand the magic of lm (Still trying)

2019-05-13 Thread Sorkin, John
-project.org; Sorkin, John Subject: Re: [R] Trying to understand the magic of lm (Still trying) John, The text below is cut out of a "how to write a package" course I gave at the R conference in Vanderbilt. I need to find a home for the course notes, because it had a lot of tidbits that ar

Re: [R] Trying to understand the magic of lm (Still trying)

2019-05-13 Thread Therneau, Terry M., Ph.D. via R-help
John,  The text below is cut out of a "how to write a package" course I gave at the R conference in Vanderbilt.   I need to find a home for the course notes, because it had a lot of tidbits that are not well explained in the R documentation. Terry T. Model frames: One of the first task

Re: [R] Trying to understand the magic of lm (Still trying)

2019-05-10 Thread David Winsemius
On 5/10/19 12:53 PM, Sorkin, John wrote: A number of people have helped me in my mission to understand how lm (and other fucntions) are able to pass a dataframe and then refer to a specific column in the dataframe. I thank everyone who has responded. I now know a bit about deparse(substitute

[R] Trying to understand the magic of lm (Still trying)

2019-05-10 Thread Sorkin, John
A number of people have helped me in my mission to understand how lm (and other fucntions) are able to pass a dataframe and then refer to a specific column in the dataframe. I thank everyone who has responded. I now know a bit about deparse(substitute(xx)), but I still don't fully understand how

Re: [R] Trying to understand the magic of lm

2019-05-09 Thread Bert Gunter
I don't think previous responses have addressed the question, which appears to be: "How does R know to look in the "data" object for the variable names in the formula?" And, of course, I could be wrong -- in which case ignore all the following. My answer to that question is: it's quite complicated

Re: [R] Trying to understand the magic of lm

2019-05-09 Thread William Michels via R-help
Hello John, Others have commented on the first half of your question, but the second half of your question looks very much like R's built-in predict() functions: >?predict >?predict.lm Best Regards, Bill. W. Michels, Ph.D. On Wed, May 8, 2019 at 6:23 PM Sorkin, John wrote: > > Can someone

Re: [R] Trying to understand the magic of lm

2019-05-09 Thread Rui Barradas
Hello, There is a "standard" deparse/substitute trick that gets the names of the variables passed to a function. There are more sophisticated ways but maybe that is what you are looking for. myfunction <- function(y, x, dataframe){ y <- deparse(substitute(y)) x <- deparse(substitute(x))

Re: [R] Trying to understand the magic of lm

2019-05-08 Thread Ben Tupper
Hi, I'm not sure if this is what you are after, but instead of defining arguments for elements of the formula why not simply pass your desired formula to your function? Cheers, Ben myfunction <- function(frmla,dataframe){ fit0 <- lm(frmla,data=dataframe) print (summary(fit0)) } # Run the

[R] Trying to understand the magic of lm

2019-05-08 Thread Sorkin, John
Can someone send me something I can read about passing parameters so I can understand how lm manages to have a dataframe passed to it, and use columns from the dataframe to set up a regression. I have looked at the code for lm and don't understand what I am reading. What I want to do is somethin