R help - Oct 2023 - Is it possible to get a downward pointing solid triangle plotting symbol in R?

You are right, sorry.

Another possible solution then: use geom_text instead of geom_point and 
use a triangle shape as text:

ggplot(data = tmpTibPoints,
        aes(x = x, y = y)) +
   geom_polygon(data = tmpTibAreas,
                aes(x = x, y = y, fill = a)) +
   geom_text(data = tmpTibPoints,
              aes(x = x, y = y, label = "?", color = c),
              size = 6) + guides(color = FALSE)



On 06-10-2023 12:11, Chris Evans via R-help wrote:
> Sadly, no.? Still shows the same legend with both sets of fill 
> mappings.? I have found a workaround, sadly
> much longer than yours (!) that does get me what I want but it is a real 
> bodge.? Still interested to see
> if there is a way to create a downward pointing solid symbol but here is 
> my bodge using new_scale_fill()
> and new_scale_color() from the ggnewscale package (many thanks to Elio 
> Campitelli for that).
> 
> library(tidyverse)
> library(ggnewscale) # allows me to change the scales used
> tibble(x = 2:9, y = 2:9,
>  ?????? ### I have used A:C to ensure the changes sort in the correct 
> order to avoid the messes of using shape to scale an ordinal variable
>  ?????? ### have to say that seems a case where it is perfectly sensible 
> to map shapes to an ordinal variable, scale_shape_manual() makes
>  ?????? ### this difficult hence this bodge
>  ?????? c = c(rep("A", 5), "B", rep("C", 2)),
>  ?????? change = c(rep("Deteriorated", 5), "No change",
rep("Improved",
> 2))) %>%
>  ? ### this is just keeping the original coding but not used below
>  ? mutate(change = ordered(change,
>  ????????????????????????? levels = c("Deteriorated", "No
change",
> "Improved"))) -> tmpTibPoints
> ### create the area mapping
> tibble(x = c(1, 5, 5, 1), y = c(1, 1, 5, 5), a = rep("a", 4))
->
> tmpTibArea1
> tibble(x = c(5, 10, 10, 5), y = c(1, 1, 5, 5), a = rep("b", 4))
->
> tmpTibArea2
> tibble(x = c(1, 5, 5, 1), y = c(5, 5, 10, 10), a = rep("c", 4))
->
> tmpTibArea3
> tibble(x = c(5, 10, 10, 5), y = c(5, 5, 10, 10), a = rep("d", 4))
->
> tmpTibArea4
> bind_rows(tmpTibArea1,
>  ????????? tmpTibArea2,
>  ????????? tmpTibArea3,
>  ????????? tmpTibArea4) -> tmpTibAreas
> ### now plot
> ggplot(data = tmpTib,
>  ?????? aes(x = x, y = y)) +
>  ? geom_polygon(data = tmpTibAreas,
>  ?????????????? aes(x = x, y = y, fill = a),
>  ?????????????? alpha = .5) +
>  ? scale_fill_manual(name = "Areas",
>  ??????????????????? values = c("orange", "purple",
"yellow", "brown"),
>  ??????????????????? labels = letters[1:4]) +
>  ? ### next two lines use ggnewscale functions to reset the scale mappings
>  ? new_scale_fill() +
>  ? new_scale_colour() +
>  ? ### can now use the open triangles and fill aesthetic to map them
>  ? geom_point(data = tmpTibPoints,
>  ???????????? aes(x = x, y = y, shape = c, fill = c, colour = c),
>  ???????????? size = 6) +
>  ? ### use the ordered variable c to get mapping in desired order
>  ? ### which, sadly, isn't the alphabetical order!
>  ? scale_shape_manual(name = "Change",
>  ?????????????????? values = c("A" = 24,
>  ????????????????????????????? "B" = 23,
>  ????????????????????????????? "C" = 25),
>  ?????????????????? labels = c("Deteriorated",
>  ????????????????????????????? "No change",
>  ????????????????????????????? "Improved")) +
>  ? scale_colour_manual(name = "Change",
>  ?????????????????? values = c("A" = "red",
>  ????????????????????????????? "B" = "grey",
>  ????????????????????????????? "C" = "green"),
>  ?????????????????? labels = c("Deteriorated",
>  ????????????????????????????? "No change",
>  ????????????????????????????? "Improved")) +
>  ? scale_fill_manual(name = "Change",
>  ?????????????????? values = c("A" = "red",
>  ????????????????????????????? "B" = "grey",
>  ????????????????????????????? "C" = "green"),
>  ?????????????????? labels = c("Deteriorated",
>  ????????????????????????????? "No change",
>  ????????????????????????????? "Improved"))
> 
> That gives the attached plot which is really what I want.? Long bodge 
> though!*
> *
> 
> On 06/10/2023 11:50, Jan van der Laan wrote:
>>
>> Does adding
>>
>> , show.legend = c("color"=TRUE, "fill"=FALSE)
>>
>> to the geom_point do what you want?
>>
>> Best,
>> Jan
>>
>> On 06-10-2023 11:09, Chris Evans via R-help wrote:
>>> library(tidyverse)
>>> tibble(x = 2:9, y = 2:9, c = c(rep("A", 5),
rep("B", 3))) ->
>>> tmpTibPoints
>>> tibble(x = c(1, 5, 5, 1), y = c(1, 1, 5, 5), a = rep("a",
4)) ->
>>> tmpTibArea1
>>> tibble(x = c(5, 10, 10, 5), y = c(1, 1, 5, 5), a =
rep("b", 4)) ->
>>> tmpTibArea2
>>> tibble(x = c(1, 5, 5, 1), y = c(5, 5, 10, 10), a =
rep("c", 4)) ->
>>> tmpTibArea3
>>> tibble(x = c(5, 10, 10, 5), y = c(5, 5, 10, 10), a =
rep("d", 4)) ->
>>> tmpTibArea4
>>> bind_rows(tmpTibArea1,
>>> ?????????? tmpTibArea2,
>>> ?????????? tmpTibArea3,
>>> ?????????? tmpTibArea4) -> tmpTibAreas
>>> ggplot(data = tmpTib,
>>> ??????? aes(x = x, y = y)) +
>>> ?? geom_polygon(data = tmpTibAreas,
>>> ??????????????? aes(x = x, y = y, fill = a)) +
>>> ?? geom_point(data = tmpTibPoints,
>>> ????????????? aes(x = x, y = y, fill = c),
>>> ????????????? pch = 24,
>>> ????????????? size = 6)
>>
>>
>> ______________________________________________
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http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.

Thanks again Jan.? That is lovely and clean and I probably should have 
seen that option.

I had anxieties about the portability of using text.? (The function will 
end up in my
https://github.com/cpsyctc/CECPfuns package so I'd like it to be fairly 
immune to character
sets and different platforms in different countries.

I'm morphing this question a lot now but I guess it's still on topic 
really.? I know
I need to put in some time to understand the complexities of R and 
platforms (I'm
pretty exclusively on Linux, Ubuntu or Debian now so have mostly done 
the ostrich thing
about these issues though I do hit problems exchanging things with my 
Spanish speaking
colleagues).? Jan or anyone: any simple reassurance or pointers to 
resources I should
best use for homework about these issues?

TIA (again!)

Chris

On 06/10/2023 12:55, Jan van der Laan wrote:
> You are right, sorry.
>
> Another possible solution then: use geom_text instead of geom_point 
> and use a triangle shape as text:
>
> ggplot(data = tmpTibPoints,
> ?????? aes(x = x, y = y)) +
> ? geom_polygon(data = tmpTibAreas,
> ?????????????? aes(x = x, y = y, fill = a)) +
> ? geom_text(data = tmpTibPoints,
> ???????????? aes(x = x, y = y, label = "?", color = c),
> ???????????? size = 6) + guides(color = FALSE)
>
[much snipped]


-- 
Chris Evans (he/him)
Visiting Professor, UDLA, Quito, Ecuador & Honorary Professor, 
University of Roehampton, London, UK.
Work web site: https://www.psyctc.org/psyctc/
CORE site: http://www.coresystemtrust.org.uk/
Personal site: https://www.psyctc.org/pelerinage2016/