log scale and limits with ggvis

Question

Hi I'm a little confused with the scales in ggvis. I'm trying to do two things: one is have a log scale (the equivalent of log="x" in plot()). I'm also looking for the equivalent of xlim=c(). In both cases, the code below is not giving the expected results.

# install.packages("ggvis", dependencies = TRUE)
library(ggvis)
df <- data.frame(a=c(1, 2, 3, 1000, 10000), b=c(0.1069, 0.0278, 0.0860, 15.5640, 30.1745))
df %>% ggvis(~a, ~b)
df %>% ggvis(~a, ~b) %>% scale_numeric("x", trans="log")

Notice that with trans="log", all dots are on the left of the plot and the scale disappears.

Next, I want to restrict the plot to certain values. I could subset the data frame but I'm looking to have the equivalent of xlim from plot().

df %>% ggvis(~a, ~b) %>% scale_numeric("x", trans="linear", domain=c(10, 40))

This is giving even weirder results, so I'm guessing I might be misinterpreting what domain does.

Thanks for your help!

Answer 1

I've encountered the same problem that you've mentioned.

Apparently, the developer of ggvis noticed this bug as well. This is currently marked as an issue. You can find the issue here: https://github.com/rstudio/ggvis/issues/230

In the context of your question:

# install.packages("ggvis", dependencies = TRUE)
library(ggvis)
df <- data.frame(a=c(1, 2, 3, 1000, 10000), b=c(0.1069, 0.0278, 0.0860, 15.5640, 30.1745))
df %>% ggvis(~a, ~b)

# Points will disapper
df %>% ggvis(~a, ~b) %>% scale_numeric("x", trans="log")
# Should work
df %>% ggvis(~a, ~b) %>% scale_numeric("x", trans="log", expand=0)

However, you may notice that after the transformation, the spacing between ticks don't appear to be uniform. But at least the dots are rendered correctly.

Answer 2

I ran into the same issue and noticed that as soon as I removed the 0 data points from my data (of which log() cannot be computed) everything started to work fine.