search for: xylm

Displaying 2 results from an estimated 2 matches for "xylm".

Did you mean: mylm
2012 Aug 28
3
date in plot, can't add regression line
...method 1): xdates <- tradeflavorbyday$timestamp[tradeflavorbyday$tradeflavor == 1] ydata <- tradeflavorbyday$x[tradeflavorbyday$tradeflavor == 1] plot(xdates, ydata, col="black", xlab="Dates", ylab="Count") Up to here it works great. Now a abline through lm: xylm <- lm(ydata~xdates) <------ this fails, can't do dates as below abline(xylm, col="black") > lm(ydata~xdates) Error in model.frame.default(formula = ydata ~ xdates, drop.unused.levels = TRUE) : invalid type (list) for variable 'xdates' So I try this instead (m...
2007 Jan 12
5
Regression lines
My simpleminded understanding of simple regression is that when plotting regression lines for x on y and y on x in the same plot, the lines should cross each other at the respective means. But, given the R function below, abline (lm(y~x)) works fine, but abline (lm(x~y)) does not. Why? function () { attach (attitude) x <- rating y <- learning detach (attitude) plot (x, y)