Control the range of values in the map legend-CodePudding

I would like to increase the range of values in the graph. In the example, the values range from 50 to 200. However, I need to distribute the values as follows: 50 75 100 125 150 175 200 and preferably using the scale_fill_gradientn function, is it possible?

volcano %>% reshape2::melt(varnames=c("x", "y")) %>% as_tibble() %>% 
        ggplot(aes(x,y, fill=value))   geom_tile()   
        scale_fill_gradientn(colours=hcl.colors(15, palette = "Purple-Green"), limits=c(50,200))

CodePudding user response：

We could use breaks along with labels argument:

library(ggplot2)
volcano %>% reshape2::melt(varnames=c("x", "y")) %>% as_tibble() %>% 
  ggplot(aes(x,y, fill=value))   geom_tile()   
  scale_fill_gradientn(colours=hcl.colors(15, palette = "Purple-Green"), limits=c(50,200),
                       breaks = c(50,75,100,125, 150, 175, 200), labels=c(50,75,100,125, 150, 175, 200))