In xiangpin/ggsymbol: Symbol Layer Based on 'ggplot2' and 'ggstar'

knitr::opts_chunk$set(tidy=FALSE,warning=FALSE,message=FALSE)
Biocpkg <- function (pkg){
    sprintf("[%s](http://bioconductor.org/packages/%s)", pkg, pkg)
}

CRANpkg <- function(pkg){
    cran <- "https://CRAN.R-project.org/package"
    fmt <- "[%s](%s=%s)"
    sprintf(fmt, pkg, cran, pkg)
}

library(ggplot2)
library(ggsymbol)

1. Introduction

The point shapes of ggplot2 based on grid provide several symbols. And the shapes are stored internally as integers. You can see the pch of points. Recently. I developed ggstar to create some regular polygons (Non-deformable). It is built with the merits of ggplot2 that was based on the grammar of graphics. It can use starshape parameter to control the selection of shapes. However, It can not be mapped with geom_point. To fill the gap. The ggsymbol was born. It provides points layer by integrating the shapes of geom_point of ggplot2 and some starshapes of ggstar

2. Total shapes

The total shapes:

library(ggplot2)
library(ggsymbol)
d <- data.frame(p=c(0:127),f=c(rep("g",26), rep("s", 7), rep("g", 95)))
d$f <- factor(d$f, levels=c("g", "s"))
p <- ggplot() + 
     geom_symbol(data=d, 
                 mapping=aes(x=p%%16, y=p%/%16, symbol=p, fill=f), 
                 size=4, stroke=0.5, show.legend=FALSE) +
     geom_text(data=d, 
               mapping=aes(x=p%%16, y=p%/%16+0.25, label=p), 
               size=3) +
     scale_symbol_identity() +
     scale_fill_manual(values=c("red", "blue")) +
     xlab(NULL) +
     ylab(NULL) +
     theme(axis.ticks=element_blank(),
           axis.text=element_blank())
p

The shapes of 0-25 and 33-127 are from pointsGrob of grid, the 26-32 are from starGrob of ggstar

3. Demo

p <- ggplot(data=iris, aes(x=Sepal.Width,y=Sepal.Length)) +
     geom_symbol(aes(symbol=Species, fill=Species), 
                 color="grey60", size=2.5,
                 stroke=0.5) +
     scale_fill_manual(values=c("#E41A1C", "#377EB8", "#4DAF4A")) +
     scale_symbol_manual(values=c(28, 22, 21))

p