How do I enter the caption and change the map scale to degrees?
library("rgeos")
library("maptools")
library("ggplot2")
library("mapproj")
cores1 = c('brown2', 'aquamarine2', 'darkgray','darkolivegreen1', 'floralwhite')
ggplot() + geom_polygon(data=mapa, mapping=aes(x=long, y=lat, group=group),
color="black", fill=cores1[mapa$tb]) +
coord_map() +
labs(y="latitude", x="longitude") +
theme(plot.title=element_text(hjust = 5))
The ggplot is not including the caption because you are assigning colors as an attribute and not as mapping . | Define attributes does not include new information in the chart (map), it only changes visual aspects. For this reason they do not need captioning.
Already mapping a variable in some aesthetic aspect (within aes(...) is to add information to the graph (map), so this information can be decoded, it needs captioning.
By simply including fill = tb within aes(...) , ggplot itself already creates the caption.
I used this object mapa to build as maps below:
mapa <- map_data("state")
mapa$tb <- factor(sample(1:5, size = nrow(mapa), replace = TRUE))
Simply remove fill=cores1[mapa$tb] and include fill = tb within aes()
ggplot() +
geom_polygon(data=mapa, mapping=aes(x=long, y=lat, group=group, fill = tb),
color="black") +
coord_map() +
labs(y="latitude", x="longitude") +
theme(plot.title=element_text(hjust = 5))
Butinthissolutionwelostthecolorsyouwanted.Toreinclinethemwiththeproposedmethodology,wehavetoaddamanualcolorscalewiththescale_fill_manual()function.Theargumentthatwillbepassedtothisfunctionisjustthevectorwiththecolorsyouhavechosen.Thevaluesargumentmustbeexplicit.Sowehave:
ggplot()+geom_polygon(data=mapa,mapping=aes(x=long,y=lat,group=group,fill=tb),color="black") +
coord_map() +
labs(y="latitude", x="longitude") +
theme(plot.title=element_text(hjust = 5)) +
scale_fill_manual(values = cores1)
