Hi Luigi, Maybe just: plot(as.numeric(factor(x,levels=x)),y,xaxt="n", main="Concentration by effect", xlab="Concentration",ylab="Effect") axis(1,at=1:4,labels=x)
Jim On Thu, Aug 27, 2020 at 10:16 PM Luigi Marongiu <marongiu.lu...@gmail.com> wrote: > > Hello, > I have a dataframe as follows: > ``` > x = c("0 pmol", "10 pmol", "100 pmol", "1000 pmol") > y = c(0.9306, 1.8906, 2.2396, 2.7917) > df = data.frame(x, y) > > > str(df) > 'data.frame': 4 obs. of 2 variables: > $ x: chr "0 pmol" "10 pmol" "100 pmol" "1000 pmol" > $ y: num 0.931 1.891 2.24 2.792 > ``` > I would like to visualize the data with the classic dots (pch=16) but: > ``` > > plot(df$y ~ df$x) > Error in plot.window(...) : need finite 'xlim' values > In addition: Warning messages: > 1: In xy.coords(x, y, xlabel, ylabel, log) : NAs introduced by coercion > 2: In min(x) : no non-missing arguments to min; returning Inf > 3: In max(x) : no non-missing arguments to max; returning -Inf > ``` > which is right because x is not numeric, so I took the factor: > ``` > plot(df$y ~ factor(df$x)) # gives bars instead of dots > plot(df$y ~ factor(df$x), pch = 16) # this also > ``` > I tried to convert directly the dataframe: > ``` > df$x = lapply(df$x, factor) > > str(df) > 'data.frame': 4 obs. of 2 variables: > $ x:List of 4 > ..$ : Factor w/ 1 level "0 pmol": 1 > ..$ : Factor w/ 1 level "10 pmol": 1 > ..$ : Factor w/ 1 level "100 pmol": 1 > ..$ : Factor w/ 1 level "1000 pmol": 1 > $ y: num 0.931 1.891 2.24 2.792 > > > plot(r$y ~ r$x, pch = 16) > Error in plot.window(...) : need finite 'xlim' values > In addition: Warning messages: > 1: In xy.coords(x, y, xlabel, ylabel, log) : NAs introduced by coercion > 2: In min(x) : no non-missing arguments to min; returning Inf > 3: In max(x) : no non-missing arguments to max; returning -Inf > ``` > If I try to pass the number of levels: > ``` > plot(df$y ~ factor(df$x, 1:4), pch = 16) # this draw a boxplot with > all data on level 1 > > > df$x = lapply(df$x, factor(1:4)) > Error in match.fun(FUN) : > 'factor(1:4)' is not a function, character or symbol > ``` > > Since the transformation has given only one level (1), my questions are: > How do I tell R to use a dot instead of a line? > What is the correct way of setting factors? > > > -- > Best regards, > Luigi > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > 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. ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.