ggplot2：Heatmap Plotting，geom_text只在選定的單元格中放置

Question

我正在使用熱圖來追蹤我的實驗中的耗損，並且我想僅在兩個第一列中打印某些日期信息，但由於某些原因，ggplot2贏得了' t接受許多遺漏的觀察結果。

這是我的情節如何看待這個時刻（通往許多日期的方式）。

任何人都可以告訴我如何限制geom_text只有兩個第一列？

查看示例代碼。

require(ggplot2) 
require(plyr) 
require(reshape) 

# create sample data 
set.seed(666) 
dfn <- data.frame(
Referral = seq(as.Date("2007-01-15"), len= 26, by="23 day"), 
VISIT01 = seq(as.Date("2008-06-15"), len= 24, by="15 day")[sample(30, 26)], 
VISIT02 = seq(as.Date("2008-12-15"), len= 24, by="15 day")[sample(30, 26)], 
VISIT03 = seq(as.Date("2009-01-01"), len= 24, by="15 day")[sample(30, 26)], 
VISIT04 = seq(as.Date("2009-03-30"), len= 24, by="60 day")[sample(30, 26)], 
VISIT05 = seq(as.Date("2010-11-30"), len= 24, by="6 day")[sample(30, 26)], 
VISIT06 = seq(as.Date("2011-01-30"), len= 24, by="6 day")[sample(30, 26)], 
Discharge = seq(as.Date("2012-03-30"), len= 24, by="30 day")[sample(30, 26)], 
Patient = factor(1:26, labels = LETTERS), 
openCase = rep(0:1, 100)[sample(100, 26)]) 

# set today's data for cases that do not have an Discharge date 
dfn$Discharge[ is.na(dfn$Discharge) ] <- as.Date("2014-01-30") 

mdfn <- melt(dfn, id=c('Patient', 'openCase'), variable_name = "Visit") 
names(mdfn)[4] <- 'Year' 

# order data in mdfn by 'Referral' in dfn 
mdfn$Patient <- factor(mdfn$Patient,levels = (dfn$Patient[order(dfn$Referral)]), 
ordered = TRUE) 

mdfn$Year2 <- ifelse(mdfn$Year != 0, 1, 0) 
mdfn$Year2[ is.na(mdfn$Year) ] <- 0 

mdfn$FWrap <- 'Core Measures' 
mdfn$FWrap[mdfn$Visit == 'Referral'] <- 'Referral' 
mdfn$FWrap[mdfn$Visit == 'VISIT05' | mdfn$Visit == 'VISIT06'] <- 'Optional Measures' 
mdfn$FWrap[mdfn$Visit == 'Discharge'] <- 'Discharge' 
mdfn$FWrap <- ordered(mdfn$FWrap, levels = c('Referral', 'Core Measures', 'Optional Measures', 'Discharge')) 

base_size <- 9 
m2 <- ggplot(mdfn, aes(Visit, Patient)) + 
geom_tile(aes(fill = Year2), colour = "gray") + 
scale_fill_gradient(low = "white", high = "steelblue") 
m2 + theme_grey(base_size = base_size) + labs(x = "", y = "") + 
scale_x_discrete(expand = c (0, 0)) + scale_y_discrete(expand = c(0, 0)) + 
opts(legend.position = "none", axis.ticks = theme_blank(), 
axis.text.x = theme_text(size = base_size * 0.8, angle = 330, hjust = 0, 
colour = "grey50")) + facet_grid(~ FWrap, scales = "free", space="free") + 
geom_text(aes (label=format(Year, "%b. %d, %Y")), size=3, colour='white') 

# this is how I thought I could solve it. 
mdfn$Yearlabel <- mdfn$Year 
mdfn$Yearlabel[mdfn$Visit != 'Referral' & mdfn$Visit != 'VISIT01'] <- NA 
# mdfn[,c(4,5,7,3)] 

m2 <- ggplot(mdfn, aes(Visit, Patient)) + 
geom_tile(aes(fill = Year2), colour = "gray") + 
scale_fill_gradient(low = "white", high = "steelblue") 
m2 + theme_grey(base_size = base_size) + labs(x = "", y = "") + 
scale_x_discrete(expand = c (0, 0)) + scale_y_discrete(expand = c(0, 0)) + 
opts(legend.position = "none", axis.ticks = theme_blank(), 
axis.text.x = theme_text(size = base_size * 0.8, angle = 330, hjust = 0, 
colour = "grey50")) + facet_grid(~ FWrap, scales = "free", space="free") + 
geom_text(aes (label=format(Yearlabel, "%b. %d, %Y")), size=3, colour='white') 

Answer 1

嘗試此，

p = ggplot(mdfn, aes(Visit, Patient)) + 
    geom_tile(aes(fill = Year2), colour = "gray") + 
    scale_fill_gradient(low = "white", high = "steelblue") + 
    theme_grey(base_size = base_size) + 
    labs(x = "", y = "") + 
    scale_x_discrete(expand = c(0, 0)) + 
    scale_y_discrete(expand = c(0, 0)) + 
    opts(legend.position = "none", axis.ticks = theme_blank(), 
     axis.text.x = theme_text(size = base_size * 0.8, angle = 330, 
     hjust = 0, colour = "grey50")) + 
    facet_grid(~ FWrap, scales = "free", space="free") 

s = subset(mdfn, Visit %in% c("Referral","VISIT01")) 
p + geom_text(aes(label=format(Year, "%b. %d, %Y")), data = s, 
       size=3, colour = 'white')