CODEWITHSUNDEEP
rplot
João Carvalho
João Carvalho

Reputation: 159

How to change line width when plotting a locfit object in R?

This sounds like a really basic question and it probably is but I can't figure out how to change the line width when plotting a locfit object. If you do a simple test, such as:

plot(locfit::locfit(~rnorm(n = 1000)))

and compare it with

plot(locfit::locfit(~rnorm(n = 1000)), lwd = 2.0)

You will see that the plotted line has the same thickness in both plots. So using lwd does not work when plotting a locfit object? Is there any workaround?

Thanks!

Upvotes: 1

Views: 65

Answers (2)

Quinten
Quinten

Reputation: 41265

You could use your model to predict the output to use lines on an empty plot which makes it possible to change the linewidth with lwd like this:

library(locfit)
#> locfit 1.5-9.7    2023-01-02
set.seed(7)
fit <- locfit(~rnorm(n = 1000))
plot(fit)


set.seed(7)
xvalues <- seq(min(rnorm(n = 1000)), max(rnorm(n = 1000)), length.out = 100)
pred <- predict(fit, xvalues)
plot(1, type="n", xlab="", ylab="", xlim=c(-3, 3), ylim=c(0, 0.4))
lines(xvalues, pred, lwd = 10)

Created on 2023-02-09 with reprex v2.0.2

Upvotes: 2

DaveArmstrong
DaveArmstrong

Reputation: 21937

There is not currently a way to do that in the existing function. When you call plot() on the locfit object, it calls preplot.locift() on your object, and then plot.preplot.locfit() which calls plot.locfit.1d(). The relevant lines from the code are:

    plot(xev[ord], yy[ord], type = "n", xlab = xlab, ylab = ylab, 
      main = main, xlim = range(x$xev[[1]]), ylim = ylim, 
      ...)
  }
  lines(xev[ord], yy[ord], type = type, lty = lty, col = col)

As you can see, the ... goes through to the plot function, but the line actually gets added with lines() which does not have access to other arguments specified in ...

Upvotes: 2

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