Legend coloring issue when plotting multiple legends for different geom_point layers

[janstrauss1]

Hi @eliocamp,

Many thanks for your time and effort to develop ggnewscale!

Unfortunately, I'm currently having some issues with the correct coloring of my legend when plotting multiple legends for two geom_point layers using color as single aesthetic. Not sure if it's a bug or just some big oversight of myself...

Please see a reprex below to illustrate my issue. What I'm trying to achieve are two legends with blue, orange and green points, one with filled colored points using geom_point(shape = 19...) and one with open circles using geom_point(shape = 21...) (like in the bottom plot).

Yet, somehow the coloring of my points in the legend get messed up?!

Many thanks for any feedback and help!

library(tidyverse)
library(ggnewscale)

## make example data
set.seed(123)
d <- tibble(
  feature = rep(base::factor(c("feature1","feature2")), 54),
  name = rep(base::factor(c("name1", "name2", "name3")), 36),
  x = runif(108, min = 0.1, max = 100),
  y = runif(108, min = 0.1, max = 100)
  )

## Point scatterplot with two legends
ggplot(data = d, aes(x = x, y = y)) +
  geom_point(shape = 19, data = subset(d, feature == "feature1"), aes(color = name), size = 3, show.legend = TRUE) +
  scale_color_manual(name = "feature1", values = c("blue", "orange", "green")) +
  new_scale_color() + # geoms below will use another color scale
  geom_point(shape = 21, data = subset(d, feature == "feature2"), aes(color = name), size = 3, show.legend = TRUE) +
  scale_color_manual(name = "feature2", values = c("blue", "orange", "green")) +
  geom_abline(linetype = "dashed") +
  xlim(0, 100) + ylim(0, 100) +
  theme_bw()

ggplot(data = d, aes(x = x, y = y)) +
  geom_point(shape = 19, data = subset(d, feature == "feature1"), aes(color = name), size = 3, show.legend = FALSE) +
  scale_color_manual(name = "feature1", values = c("blue", "orange", "green")) +
  new_scale_color() + # geoms below will use another color scale
  geom_point(shape = 21, data = subset(d, feature == "feature2"), aes(color = name), size = 3, show.legend = TRUE) +
  scale_color_manual(name = "feature2", values = c("blue", "orange", "green")) +
  geom_abline(linetype = "dashed") +
  xlim(0, 100) + ylim(0, 100) +
  theme_bw()

^{Created on 2021-06-07 by the reprex package (v2.0.0)}

sessionInfo()
#> R version 4.0.5 (2021-03-31)
#> Platform: x86_64-apple-darwin17.0 (64-bit)
#> Running under: macOS Catalina 10.15.7
#> 
#> Matrix products: default
#> BLAS:   /Library/Frameworks/R.framework/Versions/4.0/Resources/lib/libRblas.dylib
#> LAPACK: /Library/Frameworks/R.framework/Versions/4.0/Resources/lib/libRlapack.dylib
#> 
#> locale:
#> [1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8
#> 
#> attached base packages:
#> [1] stats     graphics  grDevices utils     datasets  methods   base     
#> 
#> loaded via a namespace (and not attached):
#>  [1] digest_0.6.27      withr_2.4.2        lifecycle_1.0.0    magrittr_2.0.1    
#>  [5] reprex_2.0.0       evaluate_0.14      highr_0.9          stringi_1.6.2     
#>  [9] rlang_0.4.11       cli_2.5.0          rstudioapi_0.13    fs_1.5.0          
#> [13] vctrs_0.3.8        rmarkdown_2.8      tools_4.0.5        stringr_1.4.0.9000
#> [17] glue_1.4.2         xfun_0.23          yaml_2.2.1         compiler_4.0.5    
#> [21] htmltools_0.5.1.1  knitr_1.33

^{Created on 2021-06-07 by the reprex package (v2.0.0)}

[eliocamp]

I started removing some bits of (probably unnecesary) code and I think that if you remove the show.legend = TRUE bits you can get the result you want. I have no idea why that's necesary, though, but hopefuly this is good enough for you right now until I can publish a proper fix.

library(ggplot2)
library(ggnewscale)

set.seed(123)
d <- data.frame(
  feature = rep(base::factor(c("feature1","feature2")), 54),
  name = rep(base::factor(c("name1", "name2", "name3")), 36),
  x = runif(108, min = 0.1, max = 100),
  y = runif(108, min = 0.1, max = 100)
)

ggplot(data = d, aes(x = x, y = y)) +
  geom_point(shape = 19, data = subset(d, feature == "feature1"), aes(color = name), size = 3) +
  scale_color_manual(name = "feature1", values = c("blue", "orange", "green")) +
  new_scale_color() +
  geom_point(shape = 21, data = subset(d, feature == "feature2"), aes(color = name), size = 3) +
  scale_color_manual(name = "feature2", values = c("blue", "orange", "green")) 

^{Created on 2021-06-07 by the reprex package (v2.0.0)}

[janstrauss1]

Hi @eliocamp,

That's certainly good enough for me.

I actually used the show.legendargument initially only for testing and playing around with different ggplot() settings. Wouldn't have expected that this might affect my plotting results.

Many thanks for your help!

[eliocamp]

Good to know. I'll leave this issue open because I feel that this is a genuine bug.

[eliocamp]

I'll close this since it's likely the same as #59.