stat_smooth - variable length differs
ggplot2, r
Solution
Formulas in `stat_smooth()` should use the names of aesthetic objects (`x`, `y`, `colour`, etc.), and not the names of the variables. See `help("stat_smooth")`:
formula: formula to use in smoothing function, eg. ‘y ~ x’, ‘y ~ poly(x, 2)’, ‘y ~ log(x)’
OP wrote:
p <- p + stat_smooth(method = "lm", formula = qt_int ~ rr)
But the correct way to write the formula is:
p <- p + stat_smooth(method = "lm", formula = y ~ x)
Which produces the expected output:
Problem
I want to plot two variables against each other using ggplot. Later on I want to use a nonlinear fit, but I am having a problem with an error message I do not fully understand. I can see that others having similar problem, but I may not be bright enough to understand the answer I have a dataset ost containing 4 variables. There is no NA's in the dataset. using ggplot2 I want to plot the data with a regression line. For simplicity I start with the simple linear regression ``` library(ggplot2) qt_int <- c(404, 402, 426, 392, 418, 410) rr <- c(1000, 958, 982, 752, 824, 844) gender <- c('male','female','female','female','female','female') deltnr <- c(10445, 1022, 9122, 60, 246, 306) df = data.frame(deltnr, gender, qt_int, rr) p <- ggplot(df, aes(rr, qt_int)) p <- p + geom_point (size = 2) p <- p + stat_smooth(method = "lm", formula = qt_int ~ rr) p ``` I get the following warning message: Warning messages: 1: 'newdata' had 80 rows but variables found have 6702 rows 2: Computation failed in `stat_smooth()`: argumenter antyder forskelligt antal rækker: 80, 6 [En: arguments suggest different number of rows: 80, 6] Strangely enough it works if I omit formula (but I want later on to do nonlinear fit, so I have to get it to work) What am I missing?