绘图上的标记点(R语言) [英] Labelling Points on a Plot (R Language)

问题描述

我正在使用R编程语言，并通过遵循

从这里开始，我试图修改这些图，以使其更易于识别.我正在尝试添加一个标签"(从1到100的数字)到每个圆圈，以便更轻松地识别每个圆圈:

我不确定是否有一种简单的方法可以在每个对应的圆上放置一个数字.查看kohonen软件包中的 som()函数(

I am using the R programming language and learning about kohonen package by following this tutorial. The kohonen R package allows the user to run Kohonen Networks (also called SOM - Self Organizing Maps), a type of unsupervised machine learning algorithm used in data visualization.

I ran the following code and produced the below plots:

#load libraries
library(kohonen) #fitting SOMs
library(RColorBrewer) #colors, using predefined palettes

#process data
iris_complete <-iris[complete.cases(iris),] #only complete cases... the iris dataset floats around in the sky with diamonds.
iris_unique <- unique(iris_complete) # Remove duplicates
iris.sc = scale(iris_unique[, 1:4])

#run the SOM
iris.grid = somgrid(xdim = 10, ydim=10, topo="hexagonal", toroidal = TRUE)
set.seed(33) #for reproducability
iris.som <- som(iris.sc, grid=iris.grid, rlen=700, alpha=c(0.05,0.01), keep.data = TRUE)

#make plots (3 different plots)
plot(iris.som, type="count")

plot(iris.som, type="dist.neighbours", 
     palette.name=grey.colors, shape = "straight")

var <- 1 #define the variable to plot
plot(iris.som, 
     type = "property", 
     property = getCodes(iris.som)[,var], 
     main=colnames(getCodes(iris.som))[var], 
     palette.name=terrain.colors)

From here, I am trying to modify these plots so that they are more recognizable. I am trying to add a "label" (a number from 1-100) to each circle so that is easier to identify each circle:

I am not sure if there is a straightforward way to place a number on each corresponding circle. Looking at the som() function in the kohonen package (https://www.rdocumentation.org/packages/kohonen/versions/2.0.19/topics/som), it seems it is possible to determine which observation belongs to which circle:

#determine which circle each observation belongs to
a = iris.som$unit.classif

#pull the original data
b = iris.som$data

#combine both of them into one frame
c = rbind(a,b)

But I am not sure if it is possible to "superimpose" these numbers on to the corresponding circles. Does anyone know if this can be done?

Update:

I tried the following code:

iris_unique$ID <- seq_along(iris_unique[,1]) 
plot(iris.som, type="mapping", bg = rgb(colour4), shape = "straight", 
     border = "grey", labels = iris_unique[,6])

or:

library(plotly)

plot1 = plot(iris.som, type="mapping", bg = rgb(colour4), shape = "straight", 
             border = "grey", labels = iris_unique[,6])

plotly_plot = ggplotly(plot1)

But I don't think that this is correct.

解决方案

You can find the coordinates of the center of each circle or hexagon in iris.som$grid$pts. One way to put the labels on the coordinates is to assign a name to each circle by using dimnames(), and then assign the names as the labels on the corresponding circle's coordinates by using text().

iris.som$grid$pts
#          x         y
#  [1,]  1.5 0.8660254
#  [2,]  2.5 0.8660254
#  [3,]  3.5 0.8660254
#  [4,]  4.5 0.8660254
#  [5,]  5.5 0.8660254
#  up to [100,] 10.0 8.6602540

# Assign a name for each coordinate. For example, "1", "2", "3", etc

dimnames(iris.som$grid$pts) = list(as.character(1:100), c("x","y"))  

#iris.som$grid$pts
#       x         y
#1    1.5 0.8660254
#2    2.5 0.8660254
#3    3.5 0.8660254
#4    4.5 0.8660254
#5    5.5 0.8660254

# Put the names on the plot 
text(iris.som$grid$pts, dimnames(iris.som$grid$pts[[1]]))

# Do the same steps for other plots
plot(iris.som, type="dist.neighbours", 
     palette.name=grey.colors, shape = "straight")
text(iris.som$grid$pts, dimnames(iris.som$grid$pts[[1]]))

Note that if you use RStudio, you may need to adjust the width of your plotting pane to display all the labels properly.

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