quieting techniques

---

p <- ggplot(data = cars) +
  aes(x = speed) +
  aes(y = dist) +
  geom_point() +
  aes(color = speed) +
  labs(title = "Correlation") + 
  labs(caption = "cars dataset") +
  theme(legend.position = c(.2,.8), 
        legend.direction = "horizontal")

Method 1: Manipulating gtable

Pros - very straightforward; not hacky, just uses existing gtable API Cons - output is no longer a ggplot object

library(grid)
library(gtable)

p_gtable <- ggplot_gtable(ggplot_build(p))
grid.newpage()
grid.draw(p_gtable)

p_gtable_legend_quiet <- gtable_filter(p_gtable, "guide-box", invert = TRUE)
grid.newpage()
grid.draw(p_gtable_legend_quiet)

Method 2: Manipulating ggplot theme

Pros - you get back a ggplot object and can keep adding layers to it Cons - quite a lot to search through and replace

p_global_theme <- ggplot2:::plot_theme(p)
typeof(p_global_theme)

## [1] "list"

names(p_global_theme)

##  [1] "line"                       "rect"                      
##  [3] "text"                       "title"                     
##  [5] "aspect.ratio"               "axis.title"                
##  [7] "axis.title.x"               "axis.title.x.top"          
##  [9] "axis.title.x.bottom"        "axis.title.y"              
## [11] "axis.title.y.left"          "axis.title.y.right"        
## [13] "axis.text"                  "axis.text.x"               
## [15] "axis.text.x.top"            "axis.text.x.bottom"        
## [17] "axis.text.y"                "axis.text.y.left"          
## [19] "axis.text.y.right"          "axis.ticks"                
## [21] "axis.ticks.x"               "axis.ticks.x.top"          
## [23] "axis.ticks.x.bottom"        "axis.ticks.y"              
## [25] "axis.ticks.y.left"          "axis.ticks.y.right"        
## [27] "axis.ticks.length"          "axis.ticks.length.x"       
## [29] "axis.ticks.length.x.top"    "axis.ticks.length.x.bottom"
## [31] "axis.ticks.length.y"        "axis.ticks.length.y.left"  
## [33] "axis.ticks.length.y.right"  "axis.line"                 
## [35] "axis.line.x"                "axis.line.x.top"           
## [37] "axis.line.x.bottom"         "axis.line.y"               
## [39] "axis.line.y.left"           "axis.line.y.right"         
## [41] "legend.background"          "legend.margin"             
## [43] "legend.spacing"             "legend.spacing.x"          
## [45] "legend.spacing.y"           "legend.key"                
## [47] "legend.key.size"            "legend.key.height"         
## [49] "legend.key.width"           "legend.text"               
## [51] "legend.text.align"          "legend.title"              
## [53] "legend.title.align"         "legend.position"           
## [55] "legend.direction"           "legend.justification"      
## [57] "legend.box"                 "legend.box.just"           
## [59] "legend.box.margin"          "legend.box.background"     
## [61] "legend.box.spacing"         "panel.background"          
## [63] "panel.border"               "panel.spacing"             
## [65] "panel.spacing.x"            "panel.spacing.y"           
## [67] "panel.grid"                 "panel.grid.major"          
## [69] "panel.grid.minor"           "panel.grid.major.x"        
## [71] "panel.grid.major.y"         "panel.grid.minor.x"        
## [73] "panel.grid.minor.y"         "panel.ontop"               
## [75] "plot.background"            "plot.title"                
## [77] "plot.title.position"        "plot.subtitle"             
## [79] "plot.caption"               "plot.caption.position"     
## [81] "plot.tag"                   "plot.tag.position"         
## [83] "plot.margin"                "strip.background"          
## [85] "strip.background.x"         "strip.background.y"        
## [87] "strip.placement"            "strip.text"                
## [89] "strip.text.x"               "strip.text.y"              
## [91] "strip.switch.pad.grid"      "strip.switch.pad.wrap"     
## [93] "strip.text.y.left"

p_elements_with_colour <- Filter(Negate(is.null), 
                                 lapply(p_global_theme, 
                                        function(element) if (is.list(element)) 
                                          element$colour))

p_elements_with_colour

## $line
## [1] "black"
## 
## $rect
## [1] "black"
## 
## $text
## [1] "black"
## 
## $axis.text
## [1] "grey30"
## 
## $axis.ticks
## [1] "grey20"
## 
## $legend.background
## [1] NA
## 
## $legend.key
## [1] NA
## 
## $panel.background
## [1] NA
## 
## $panel.grid
## [1] "white"
## 
## $plot.background
## [1] "white"
## 
## $strip.background
## [1] NA
## 
## $strip.text
## [1] "grey10"

ggplot list

p +
  aes(color = NULL) ->
p

p$layers[[1]]$geom$default_aes$colour ->
  color

alpha(color, alpha = .3) ->
 p$layers[[1]]$geom$default_aes$colour 

p