An embedded and charset-unspecified text was scrubbed... Name: not available URL: <https://stat.ethz.ch/pipermail/r-help/attachments/20130213/56979756/attachment.pl>
Need Help Plotting "Line" for multiple linear regression
3 messages · Craig O'Connell, PIKAL Petr, Greg Snow
Hi
-----Original Message-----
From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
project.org] On Behalf Of Craig O'Connell
Sent: Wednesday, February 13, 2013 11:03 PM
To: r-help at r-project.org
Subject: [R] Need Help Plotting "Line" for multiple linear regression
Hello,
My name is Craig and I need help plotting a "line" for a multiple
linear regression in R.
Here is my sample data (filename: convis.txt)
Output of convis.txt is (vis and density being predictors of either
avoidance or entrance):
vis den avoid entrance
1 10 1 0.0000 0.0000
2 10 3 0.8750 0.0000
3 8 3 0.8180 0.0300
4 8 3 0.6670 0.0667
5 8 1 0.2110 0.0000
6 6 1 0.2500 0.0000
7 10 1 0.3000 0.0000
8 10 1 0.1050 0.0000
9 8 1 0.7000 0.1000
10 3 5 0.1176 0.0588
11 3 5 0.3077 0.1150
12 3 9 0.9090 0.0900
13 3 7 0.7778 0.1110
14 3 5 0.5560 0.1110
15 3 1 0.5710 0.0000
16 3 4 0.5710 0.0000
In order to do the multiple regression, I used the following coding:
double=read.table("convis.txt",header=TRUE)
attach(double)
double
stem(vis)
stem(den)
stem(avoid)
stem(entrance)
plot(entrance,vis*den) *as means to see how the interaction
This is not an interaction, you just multiply vis and den and plot entrance on x axis and vis*den on y axis, so basically you want to model vis*den by entrance.
between visibility and density may impact entrance behaviors model6=lm(entrance~vis*den)
This model is oposite of what you plotted.
model6 summary(model6) *abline(model6) *Here is the issue as I used this for my simple linear regression technique, but do not know what to use for a multiple regression*
You seem to not understand how the multiple regression output and abline works. Based on what you want you can do plot(vis*den, entrance) model6 <- lm(entrance~I(vis*den)) abline(model6) however your model will have only intercept and one coefficient for variable x=vis*den If you want to have separate coefficients for vis ***and*** den and their interaction you can use model6=lm(entrance~vis*den) but in this case resulting coefficients are Intercept, vis, den and interaction between vis and den. In that case beside of other procedures for model evaluation you can do. plot(entrance, fitted(model6)) abline(0,1) Regards Petr
If anybody can provide some feedback on this, it would be greatly appreciated. Kind Regards, Craig -- <>< <>< <>< Craig O'Connell University of Massachusetts Dartmouth Marine Biologist www.youtube.com/craigpoconnell craigosea.blogspot.com [[alternative HTML version deleted]]
______________________________________________ R-help at r-project.org mailing list 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.
An embedded and charset-unspecified text was scrubbed... Name: not available URL: <https://stat.ethz.ch/pipermail/r-help/attachments/20130214/8706700c/attachment.pl>