introduce donut_radius and bg_circle_radius parameters

R/geom_scatterpie.R

@@ -8,14 +8,18 @@
 ##' @param pie_scale amount to scale the pie size if there is no radius mapping exists
 ##' @param sorted_by_radius whether plotting large pie first
 ##' @param legend_name name of fill legend
-##' @param long_format whether use long format of input data
+##' @param long_format logical whether use long format of input data
+##' @param donut_radius numeric the radius of donut chart (relative the radius of circle), default is NULL.
+##' it should be between 0 and 1, if it is provided, the donut chart will be displayed instead of pie chart.
+##' @param bg_circle_radius numeric the radius of background circle, default is FALSE, we suggest setting it 
+##' to between 1 and 1.5 .
 ##' @param ... additional parameters
-##' @importFrom ggforce geom_arc_bar
+##' @importFrom ggforce geom_arc_bar geom_circle
 ##' @importFrom utils modifyList
 ##' @importFrom tidyr gather
 ##' @importFrom rlang enquo
 ##' @importFrom rlang !!
-##' @importFrom ggplot2 aes_
+##' @importFrom ggplot2 aes_ aes
 ##' @importFrom ggfun get_aes_var
 ##' @importFrom stats as.formula
 ##' @importFrom dplyr bind_rows group_by group_split
@@ -30,8 +34,27 @@
 ##' ggplot() + geom_scatterpie(aes(x=x, y=y), data=d, cols=c("A", "B", "C")) + coord_fixed()
 ##' d <- tidyr::gather(d, key="letters", value="value", -x:-y)
 ##' ggplot() + geom_scatterpie(aes(x=x, y=y), data=d, cols="letters", long_format=TRUE) + coord_fixed()
+##' p1 <- ggplot() + 
+##'       geom_scatterpie(
+##'         mapping = aes(x=x, y=y), data=d, cols="letters", 
+##'         long_format=TRUE, 
+##'         donut_radius=.5
+##'       ) + 
+##'       coord_fixed()
+##' p1
+##' p2 <- ggplot() + 
+##'       geom_scatterpie(
+##'         mapping = aes(x=x, y=y), data=d, cols="letters", 
+##'         long_format=TRUE, 
+##'         donut_radius = .5, 
+##'         bg_circle_radius = 1.2
+##'       ) + 
+##'       coord_fixed()
+##' p2
 ##' @author Guangchuang Yu
-geom_scatterpie <- function(mapping=NULL, data, cols, pie_scale = 1, sorted_by_radius = FALSE, legend_name = "type", long_format=FALSE, ...) {
+geom_scatterpie <- function(mapping=NULL, data, cols, pie_scale = 1, 
+                            sorted_by_radius = FALSE, legend_name = "type", 
+                            long_format=FALSE, donut_radius=NULL, bg_circle_radius=NULL, ...) {
     if (is.null(mapping))
         mapping <- aes_(x = ~x, y = ~y)
     mapping <- modifyList(mapping,
@@ -45,6 +68,16 @@ geom_scatterpie <- function(mapping=NULL, data, cols, pie_scale = 1, sorted_by_r
         size <- diff(range(data[, xvar]))/ 50 * pie_scale
         data$r <- size
         mapping <- modifyList(mapping, aes_(r=size))
+        if (!is.null(donut_radius)){
+            donut_radius <- .check_donut_radius(donut_radius)
+            mapping <- modifyList(mapping, aes_(r0 = ~size * donut_radius))
+        }
+    }else{
+        if (!is.null(donut_radius)){
+            rvar <- get_aes_var(mapping, 'r')
+            donut_radius <- .check_donut_radius(donut_radius)
+            mapping <- modifyList(mapping, aes_(r0 = ~rvar * donut_radius))
+        }
     }
 
     names(mapping)[match(c("x", "y"), names(mapping))] <- c("x0", "y0")
@@ -76,19 +109,38 @@ geom_scatterpie <- function(mapping=NULL, data, cols, pie_scale = 1, sorted_by_r
       mapping <- modifyList(mapping, aes_(group = ~.group.id))
     }
 
-    if (!sorted_by_radius) {
-        return(geom_arc_bar(mapping, data=df, stat='pie', inherit.aes=FALSE, ...))
-    }
-
     if ('r' %in% colnames(df)){
         rvar <- 'r'
     }else{
         rvar <- get_aes_var(mapping, 'r')
     }
-
-    lapply(split(df, df[,rvar, drop=TRUE])[as.character(sort(unique(df[,rvar, drop=TRUE]), decreasing=TRUE))], function(d) {
-        geom_arc_bar(mapping, data=d, stat='pie', inherit.aes=FALSE, ...)
-    })
+
+    if (!sorted_by_radius) {
+        pie.layer <- geom_arc_bar(mapping, data=df, stat='pie', inherit.aes=FALSE, ...)
+        if (!is.null(bg_circle_radius)){
+            mapping.circle <- mapping[names(mapping) %in% c('x0', 'y0')]
+            dt <- .extract_mapping_df(df, mapping, extract_aes = c('x0', 'y0'), col_var=rvar)
+            mapping.circle <- modifyList(mapping.circle, aes(r = !!as.symbol(rvar) * bg_circle_radius))
+            circle.layer <- geom_circle(data = dt, mapping = mapping.circle, inherit.aes=FALSE, ...)
+            pie.layer <- list(circle.layer, pie.layer)
+        }
+        return(pie.layer)
+    }
+
+    lapply(split(df, df[,rvar, drop=TRUE])[as.character(sort(unique(df[,rvar, drop=TRUE]), decreasing=TRUE))], 
+           function(d) 
+           {
+        pie.layer <- geom_arc_bar(mapping, data=d, stat='pie', inherit.aes=FALSE, ...)
+        if (!is.null(bg_circle_radius)){
+            mapping.circle <- mapping[names(mapping) %in% c('x0', 'y0', 'r')]
+            d2 <- .extract_mapping_df(d, mapping, extract_aes = c('x0', 'y0', 'r'), col_var = rvar)
+            mapping.circle <- modifyList(mapping.circle, aes(r = !!as.symbol(rvar) * bg_circle_radius))
+            circle.layer <- geom_circle(data = d2, mapping = mapping.circle, inherit.aes=FALSE, ...)
+            pie.layer <- list(circle.layer, pie.layer)
+        }
+        return(pie.layer)
+      }
+   )
 }
 
 

R/utilities.R

@@ -16,3 +16,22 @@ is_fixed_radius <- function(rvar) {
     }
     return(TRUE)
 }
+
+.check_donut_radius <- function(x){
+    if (x > 1){
+        cli::cli_warn("The `donut.radius` should be range 0 and 1, it was set to 0.5 automatically.")
+        x <- 0.5
+    }
+    return(x)
+}
+
+.extract_mapping_df <- function(data,
+                                mapping, 
+                                extract_aes = c('x0', 'y0'),
+                                col_var = NULL
+                                ){
+    extract.var <- lapply(extract_aes, function(x)get_aes_var(mapping, x)) |> unlist()
+    extract.var <- union(col_var, extract.var)
+    df <- data[, colnames(data) %in% extract.var, drop=FALSE] |> dplyr::distinct()
+    return(df)
+}