I want to plot the regression line of a log regression into a plot with my normal, nonlog, data. for example x <- (1,2,3,4,5) y <- (6,7,8,9,10) plot (x,y) I tried a log-regression by a <- glm (log(y) ~ log(x)) and then i tried to insert the answer to my graph, where the standard values are shown: abline (a, col="red") unfortunately it does not work.... -- View this message in context: http://r.789695.n4.nabble.com/plotting-log-regression-tp4653087.html Sent from the R help mailing list archive at Nabble.com.
plotting log regression
4 messages · Rui Barradas, mrkooper, Andrews, Chris
Hello, How can you expect to see the fit line if you are ploting x and y values, not their logarithms? And your definitions of x and y are wrong, they should use c(). x <- c(1,2,3,4,5) y <- c(6,7,8,9,10) plot(log(x), log(y)) fit <- lm(log(y) ~ log(x)) # Same as glm abline(fit) Please read R-intro, in the doc folder of your installation of R. Hope this helps, Rui Barradas Em 14-12-2012 13:58, mrkooper escreveu:
I want to plot the regression line of a log regression into a plot with my normal, nonlog, data. for example x <- (1,2,3,4,5) y <- (6,7,8,9,10) plot (x,y) I tried a log-regression by a <- glm (log(y) ~ log(x)) and then i tried to insert the answer to my graph, where the standard values are shown: abline (a, col="red") unfortunately it does not work.... -- View this message in context: http://r.789695.n4.nabble.com/plotting-log-regression-tp4653087.html Sent from the R help mailing list archive at Nabble.com.
______________________________________________ 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.
2 days later
Thank you for your help! i'm still wondering if it's possible to transfer the results of the log regression into a plot with the nonlog values. -- View this message in context: http://r.789695.n4.nabble.com/plotting-log-regression-tp4653087p4653279.html Sent from the R help mailing list archive at Nabble.com.
Your example seems strange because a line fits on the x-y scale; not on the log(x)-log(y) scale. Anyway, here is my example. You can build on it for more general data. x <- exp(1:10) y <- exp(10:1 + rnorm(10)) logmod <- lm(log(y)~log(x)) logypred <- predict(logmod) plot(y~x) lines(exp(logypred)~x, col=2) plot(y~x, log="xy") lines(exp(logypred)~x, col=2) Chris -----Original Message----- From: Rui Barradas [mailto:ruipbarradas at sapo.pt] Sent: Friday, December 14, 2012 12:06 PM To: mrkooper Cc: r-help at r-project.org Subject: Re: [R] plotting log regression Hello, How can you expect to see the fit line if you are ploting x and y values, not their logarithms? And your definitions of x and y are wrong, they should use c(). x <- c(1,2,3,4,5) y <- c(6,7,8,9,10) plot(log(x), log(y)) fit <- lm(log(y) ~ log(x)) # Same as glm abline(fit) Please read R-intro, in the doc folder of your installation of R. Hope this helps, Rui Barradas Em 14-12-2012 13:58, mrkooper escreveu:
I want to plot the regression line of a log regression into a plot with my normal, nonlog, data. for example x <- (1,2,3,4,5) y <- (6,7,8,9,10) plot (x,y) I tried a log-regression by a <- glm (log(y) ~ log(x)) and then i tried to insert the answer to my graph, where the standard values are shown: abline (a, col="red") unfortunately it does not work.... -- View this message in context: http://r.789695.n4.nabble.com/plotting-log-regression-tp4653087.html Sent from the R help mailing list archive at Nabble.com.
______________________________________________ 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.
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