How to write after decimal zero in ggplot (geom_text)

问题

I am wondering how i can put after decimal zero in the faceted ggplot plot. Following picture make it more clear. I would like to write r-squared =0.61 and 0.30 in two facets of ggplot using geom_text. It writes 0.61 properly but writes only 0.3 and not 0.30 in second plot. see the figure. My working data and codes are below.

 dput(ssdata)
 structure(list(Value = c(0.0776799352545487, 0.0249900650410425, 
 0.0530261633888124, 0.0567436050950435, 0.0120449632406235, 0.0148445528174501, 
 0.00322103330067226, 0.0841269995036878, 0.0667567417539399, 
 0.0353554071120496, 0.0168391247006024, 0.0187554325376238, 0.0862325738977503, 
 0.0353403282165527, 0.0459572764543387, 0.0153406669137266, 0.0390336212195695, 
 0.0620484352111816, 0.0489626884460449, 0.0221186299849756), 
 Ft = c(1, 1, 1, 1, 2, 2, 2, 1, 1, 1, 1, 1, 1, 2, 1, 2, 1, 
 1, 1, 1), RT = c(869, 722, 1790, 875, 1524, 1314, 1061, 919, 
 1525, 1127, 932, 1182, 1046, 1004, 1238, 1497, 1066, 1500, 
 1654, 903), Season = c("Winter", "Spring", "Spring", "Winter", 
 "Summer", "Fall", "Fall", "Winter", "Winter", "Spring", "Summer", 
 "Summer", "Winter", "Winter", "Spring", "Fall", "Spring", 
 "Winter", "Spring", "Spring"), fac = structure(c(1L, 2L, 
 2L, 1L, 3L, 4L, 4L, 1L, 1L, 2L, 3L, 3L, 1L, 1L, 2L, 4L, 2L, 
 1L, 2L, 2L), .Label = c("Winter", "Spring", "Summer", "Fall"
 ), class = "factor")), .Names = c("Value", "Ft", "RT", "Season", 
 "fac"), row.names = c(51L, 1320L, 1341L, 427L, 2384L, 3342L, 
  3111L, 16L, 330L, 1062L, 2501L, 2500L, 61L, 711L, 941L, 3171L, 
 973L, 610L, 1418L, 1524L), class = "data.frame")

 dput(data)
 structure(list(fac = structure(1:4, .Label = c("Winter", "Spring", 
 "Summer", "Fall"), class = "factor"), tp = c("R^2== 0.26", "R^2== 0.61", 
 "R^2== 0.30", "R^2== 0.22"), ttp = c("n== 844", "n== 844", "n== 844", 
  "n== 844"), family = c("serif", "serif", "serif", "serif"), fontface = c("italic", 
  "italic", "italic", "italic"), size = c(5, 5, 5, 5), x = c(0, 
  0, 0.8, 0.8), y = c(2000, 2000, 2000, 2000), yy = c(1800, 1800, 
  1800, 1800)), .Names = c("fac", "tp", "ttp", "family", "fontface", 
  "size", "x", "y", "yy"), row.names = c(NA, -4L), class = "data.frame")

Code:

plot.sea1<-ggplot(ssdata,aes(x=10*Value, y= RT))+
geom_point()+
#stat_smooth(method="loess", se=F,fullrange=TRUE, size=0.8)+
facet_grid(fac~.,scales="free_x")+
geom_text(data=data,aes(x=x,y=y,label=tp),parse=TRUE,inherit.aes=F,show_guide=  F,size=3)
plot.sea1

回答1:

You are having problems due to how the r2 strings.you are passing are getting parsed.

EDIT

Using methods from earlier post (below) on your data:

lm_eqn <- function(ssdata){
           m = lm(RT ~ Value, ssdata)
           eq <- substitute(italic(r)^2~"="~r2, 
                   list(r2 = formatC(summary(m)$r.squared, digits = 2)))
           as.character(as.expression(eq))          
        }

eq1 <- ddply(ssdata,.(fac), lm_eqn)

plot.sea1 <- ggplot(ssdata,aes(x=10*Value, y= RT)) +
                 geom_point() +
                 stat_smooth(method="loess", se=F,fullrange=TRUE, size=0.8) +
                 facet_grid(fac~.,scales="free_x") + 
                 geom_text(data=eq1 ,aes(x = 0.6, y = 1200, label=V1), 
                                                               parse = TRUE)

First post

# example using mtcars
data(mtcars)

# facetted plot similar to yours
p <- ggplot(mtcars, aes(mpg, wt)) + 
        geom_point(aes(color=factor(vs))) +
        stat_smooth(method="loess", se=F,fullrange=TRUE, size=0.8) + 
        facet_grid(am ~.)


eq <- data.frame(am = c(0,1), r2 =  c("italic(r)^2 == 0.30",
               as.character(as.expression(substitute(italic(r)^2~"="~r2, 
                       list(r2 = formatC(0.30, format = "f", digits = 2)))))))

eq
#  am                         r2
# 1  0        italic(r)^2 == 0.30
# 2  1 italic(r)^2 ~ "=" ~ "0.30"

# add the text
p + geom_text(data=eq ,aes(x = 25, y = 5, label=r2), parse=TRUE)

Only the second is parsed correctly. When you just pass the string the training zero is removed.

So using JT85 answer here gives an alternate way to generate the r2 strings.

# define a function to generate r2 string
lm_eqn <- function(mtcars) {
              m = lm(mpg ~ wt, mtcars)
              eq <- substitute(italic(r)^2~"="~r2, 
                          list(r2 = formatC(summary(m)$r.squared, digits = 2)))
                                               as.character(as.expression(eq))   
          }

library(plyr)
# generate r2 string
eq1 <- ddply(mtcars, .(am), lm_eqn)

# plot
p + geom_text(data=eq1 aes(x = 25, y = 5, label=V1), parse = TRUE)

来源：https://stackoverflow.com/questions/25108062/how-to-write-after-decimal-zero-in-ggplot-geom-text

标签

ggplot2

decimal

facet

geom-text