On Sep 26, 2012, at 10:31 PM, Krunal Nanavati wrote:
Dear Rui,
Thanks for your time.
I have a question though, when I run the 5 regression, whose outputs are
stored in “lm.list[i]”, I only get the coefficients for the Intercept,
Price, Trend & Seasonality as below
lm.list[1]
[[1]]
Call:
lm(formula = as.formula(fmla), data = tryout)
Coefficients:
(Intercept) Price4 Trend Seasonality
9923123 -2606826 64616 551392
summ.list <- lapply(lm.list, summary)
coef.list <- lapply(summ.list, coef)
coef.list
I am also looking out for t stats and p value and R squared.
For the r.squared
rsq.vec <- sapply(summ.list, "$", "r.squared")
adj.rsq <- sapply(summ.list, "$", "adj.r.squared")
Do you know,
how can I get all these statistics. Also, why is “ as.formula “ used in the
lm function. It should work without that as well, right?
No.
Can you please tell me, why the code that I had written, does not work with
R. I thought it should work perfectly.
In R there is a difference between expression objects and character objects.
Thanks & Regards,
Krunal Nanavati
9769-919198
*From:* Rui Barradas [mailto:ruipbarra...@sapo.pt]
*Sent:* 26 September 2012 17:13
*To:* Krunal Nanavati
*Cc:* r-help@r-project.org
*Subject:* Re: [R] Running different Regressions using for loops
Hello,
Try the following.
#cnames <- names(tryout) # in your code, use this one
cnames <- c("Volume", "Price1", "Price2", "Price3", "Price4", "Price5",
"Trend", "Seasonaliy")
price <- cnames[grep("Price", cnames)]
resp <- cnames[1]
regr <- cnames[7:8]
#lm.list <- vector("list", 5)
for(i in 1:5){
regress <- paste(price[i], paste(regr, collapse = "+"), sep = "+")
fmla <- paste(resp, regress, sep = "~")
print(fmla)
#lm.list[[i]] <- lm(as.formula(fmla), data = tryout)
}
Hope this helps,
Rui Barradas
Em 26-09-2012 08:08, Krunal Nanavati escreveu:
Hi,
I am trying to run many different regressions using a FOR Loop.
The input data that is read into R has the following variables
· Volume
· Price2
· Price3
· Price4
· Price5
· Trend
· Seasonality
I want to run 5 regressions, with the Volume as an dependent variable and
Price, Trend & Seasonality as independent variables. I have read the above
mentioned variables in a variable called “tryout”
I am entering the following syntax in R
for(i in 1:5)
+ {
+ result[i]=lm(Volume~Price[i]+Trend+Seasonaliy,data=tryout)
+ summary(result[i])
+ }
After running these lines…I am getting the following error message
Error in eval(expr, envir, enclos) : object 'Price' not found
Can someone help me out with this error message. Appreciate for your time
and consideration.
[[alternative HTML version deleted]]
David Winsemius, MD
Alameda, CA, USA
