diff --git a/chap11/fig11-11-left.R b/chap11/fig11-11-left.R
index 39ca9be..d607e80 100644
--- a/chap11/fig11-11-left.R
+++ b/chap11/fig11-11-left.R
@@ -4,17 +4,17 @@ load('output/result-model11-8.RData')
 ms <- rstan::extract(fit_vb)
 
 probs <- c(0.1, 0.25, 0.5, 0.75, 0.9)
-idx <- expand.grid(1:K, 1:I)
+idx <- expand.grid(tag=1:K, item=1:I)
 
-d_qua <- t(apply(idx, 1, function(x) quantile(ms$phi[,x[1],x[2]], probs=probs)))
-d_qua <- data.frame(idx, d_qua)
-colnames(d_qua) <- c('tag', 'item', paste0('p', probs*100))
+qua <- apply(idx, 1, function(x) quantile(ms$phi[,x[1],x[2]], probs=probs))
+d_est <- data.frame(idx, t(qua), check.names=FALSE)
 
-p <- ggplot(data=d_qua, aes(x=item, y=p50))
-p <- p + theme_bw(base_size=18)
-p <- p + facet_wrap(~tag, ncol=3)
-p <- p + coord_flip()
-p <- p + scale_x_reverse(breaks=c(1, seq(20, 120, 20)))
-p <- p + geom_bar(stat='identity')
-p <- p + labs(x='ItemID', y='phi[k,y]')
+p <- ggplot(data=d_est, aes(x=item, y=`50%`)) +
+  theme_bw(base_size=18) +
+  theme(axis.text.x=element_text(angle=40, vjust=1, hjust=1)) +
+  facet_wrap(~tag, ncol=3) +
+  coord_flip() +
+  scale_x_reverse(breaks=c(1, seq(20, 120, 20))) +
+  geom_bar(stat='identity') +
+  labs(x='ItemID', y='phi[k,y]')
 ggsave(file='output/fig11-11-left.png', plot=p, dpi=300, w=7, h=5)
diff --git a/chap11/fig11-11-right.R b/chap11/fig11-11-right.R
index 4551a9a..966ffdd 100644
--- a/chap11/fig11-11-right.R
+++ b/chap11/fig11-11-right.R
@@ -4,18 +4,17 @@ load('output/result-model11-8.RData')
 ms <- rstan::extract(fit_vb)
 
 probs <- c(0.1, 0.25, 0.5, 0.75, 0.9)
-idx <- expand.grid(1:N, 1:K)
+idx <- expand.grid(person=1:N, tag=1:K)
 
-d_qua <- t(apply(idx, 1, function(x) quantile(ms$theta[,x[1],x[2]], probs=probs)))
-d_qua <- data.frame(idx, d_qua)
-colnames(d_qua) <- c('person', 'tag', paste0('p', probs*100))
+qua <- apply(idx, 1, function(x) quantile(ms$theta[,x[1],x[2]], probs=probs))
+d_est <- data.frame(idx, t(qua), check.names=FALSE)
 
-p <- ggplot(data=subset(d_qua, person %in% c(1,50)), aes(x=tag, y=p50))
-p <- p + theme_bw(base_size=18)
-p <- p + facet_wrap(~person, nrow=2)
-p <- p + coord_flip()
-p <- p + scale_x_reverse(breaks=1:6)
-p <- p + geom_bar(stat='identity')
-p <- p + geom_errorbar(aes(ymin=p25, ymax=p75), width=0.25)
-p <- p + labs(x='tag', y='theta[n,k]')
+p <- ggplot(data=subset(d_est, person %in% c(1,50)), aes(x=tag, y=`50%`)) +
+  theme_bw(base_size=18) +
+  facet_wrap(~person, nrow=2) +
+  coord_flip() +
+  scale_x_reverse(breaks=1:6) +
+  geom_bar(stat='identity') +
+  geom_errorbar(aes(ymin=`25%`, ymax=`75%`), width=0.25) +
+  labs(x='tag', y='theta[n,k]')
 ggsave(file='output/fig11-11-right.png', plot=p, dpi=300, w=5, h=5)
diff --git a/chap11/fig11-2.R b/chap11/fig11-2.R
index 42001bb..5f68a0c 100644
--- a/chap11/fig11-2.R
+++ b/chap11/fig11-2.R
@@ -3,10 +3,10 @@ library(ggplot2)
 d <- read.csv(file='input/data-mix1.txt')
 dens <- density(d$Y)
 
-p <- ggplot(data=d, aes(x=Y))
-p <- p + theme_bw(base_size=18)
-p <- p + geom_histogram(binwidth=0.5, colour='black', fill='white')
-p <- p + geom_density(aes(y=..count.. * 0.5), alpha=0.35, colour='black', fill='gray20')
-p <- p + scale_y_continuous(breaks=seq(from=0, to=10, by=2))
-p <- p + labs(x='Y') + xlim(range(dens$x))
+p <- ggplot(data=d, aes(x=Y)) +
+  theme_bw(base_size=18) +
+  geom_histogram(binwidth=0.5, colour='black', fill='white') +
+  geom_density(aes(y=..count.. * 0.5), alpha=0.35, colour='black', fill='gray20') +
+  scale_y_continuous(breaks=seq(from=0, to=10, by=2)) +
+  labs(x='Y') + xlim(range(dens$x))
 ggsave(file='output/fig11-2.png', plot=p, dpi=300, w=4, h=3)
diff --git a/chap11/fig11-3.R b/chap11/fig11-3.R
index b1d0bde..a02b25c 100644
--- a/chap11/fig11-3.R
+++ b/chap11/fig11-3.R
@@ -3,9 +3,9 @@ library(ggplot2)
 d <- read.csv(file='input/data-mix2.txt')
 dens <- density(d$Y)
 
-p <- ggplot(data=d, aes(x=Y))
-p <- p + theme_bw(base_size=18)
-p <- p + geom_histogram(color='black', fill='white')
-p <- p + geom_density(aes(y=..count..), alpha=0.35, colour='black', fill='gray20')
-p <- p + labs(x='Y') + xlim(range(dens$x))
+p <- ggplot(data=d, aes(x=Y)) +
+  theme_bw(base_size=18) +
+  geom_histogram(color='black', fill='white') +
+  geom_density(aes(y=..count..), alpha=0.35, colour='black', fill='gray20') +
+  labs(x='Y') + xlim(range(dens$x)) 
 ggsave(file='output/fig11-3.png', plot=p, dpi=300, w=4, h=3)
diff --git a/chap11/fig11-4.R b/chap11/fig11-4.R
index 030ae11..4a23b4a 100644
--- a/chap11/fig11-4.R
+++ b/chap11/fig11-4.R
@@ -8,17 +8,17 @@ d$Sake <- as.factor(d$Sake)
 N_col <- ncol(d)
 ggp <- ggpairs(d, upper='blank', diag='blank', lower='blank')
 
-for(i in 1:N_col) {
+for (i in 1:N_col) {
   x <- d[,i]
-  p <- ggplot(data.frame(x), aes(x=x))
-  p <- p + theme_bw(base_size=14)
-  p <- p + theme(axis.text.x=element_text(angle=40, vjust=1, hjust=1))
+  p <- ggplot(data.frame(x), aes(x=x)) +
+    theme_bw(base_size=14) +
+    theme(axis.text.x=element_text(angle=40, vjust=1, hjust=1))
   if (class(x) == 'factor') {
     p <- p + geom_bar(color='grey5', fill='grey80')
   } else {
     bw <- ifelse(colnames(d)[i] == 'Y', 1, (max(x)-min(x))/10)
-    p <- p + geom_histogram(binwidth=bw, color='grey5', fill='grey80')
-    p <- p + geom_line(eval(bquote(aes(y=..count..*.(bw)))), stat='density')
+    p <- p + geom_histogram(binwidth=bw, color='grey5', fill='grey80') +
+      geom_line(eval(bquote(aes(y=..count..*.(bw)))), stat='density')
   }
   p <- p + geom_label(data=data.frame(x=-Inf, y=Inf, label=colnames(d)[i]), aes(x=x, y=y, label=label), hjust=0, vjust=1)
   ggp <- putPlot(ggp, p, i, i)
@@ -27,44 +27,42 @@ for(i in 1:N_col) {
 zcolat <- seq(-1, 1, length=81)
 zcolre <- c(zcolat[1:40]+1, rev(zcolat[41:81]))
 
-for(i in 1:(N_col-1)) {
-  for(j in (i+1):N_col) {
+for (i in 1:(N_col-1)) {
+  for (j in (i+1):N_col) {
     x <- as.numeric(d[,i])
     y <- as.numeric(d[,j])
     r <- cor(x, y, method='spearman', use='pairwise.complete.obs')
     zcol <- lattice::level.colors(r, at=zcolat, col.regions=grey(zcolre))
     textcol <- ifelse(abs(r) < 0.4, 'grey20', 'white')
     ell <- ellipse::ellipse(r, level=0.95, type='l', npoints=50, scale=c(.2, .2), centre=c(.5, .5))
-    p <- ggplot(data.frame(ell), aes(x=x, y=y))
-    p <- p + theme_bw() + theme(
+    p <- ggplot(data.frame(ell), aes(x=x, y=y)) + theme_bw() + theme(
       plot.background=element_blank(),
       panel.grid.major=element_blank(), panel.grid.minor=element_blank(),
-      panel.border=element_blank(), axis.ticks=element_blank()
-    )
-    p <- p + geom_polygon(fill=zcol, color=zcol)
-    p <- p + geom_text(data=NULL, x=.5, y=.5, label=100*round(r, 2), size=6, col=textcol)
+      panel.border=element_blank(), axis.ticks=element_blank()) +
+      geom_polygon(fill=zcol, color=zcol) +
+      geom_text(data=NULL, x=.5, y=.5, label=100*round(r, 2), size=6, col=textcol)
     ggp <- putPlot(ggp, p, i, j)
   }
 }
 
-for(j in 1:(N_col-1)) {
-  for(i in (j+1):N_col) {
+for (j in 1:(N_col-1)) {
+  for (i in (j+1):N_col) {
     x <- d[,j]
     y <- d[,i]
     if (class(x) == 'factor' && class(y) == 'factor') {
-      p <- ggplot(reshape2::melt(table(x,y)), aes(x=x, y=y))
-      p <- p + theme_bw(base_size=14)
-      p <- p + geom_point(aes(size=value), color='grey80')
-      p <- p + geom_text(aes(label=value))
-      p <- p + scale_size_area(max_size=8)
-      p <- p + scale_x_continuous(breaks=0:1, limits=c(-0.5,1.5)) + scale_y_continuous(breaks=0:1, limits=c(-0.5,1.5))
+      p <- ggplot(reshape2::melt(table(x,y)), aes(x=x, y=y)) +
+        theme_bw(base_size=14) +
+        geom_point(aes(size=value), color='grey80') +
+        geom_text(aes(label=value)) +
+        scale_size_area(max_size=8) +
+        scale_x_continuous(breaks=0:1, limits=c(-0.5,1.5)) + scale_y_continuous(breaks=0:1, limits=c(-0.5,1.5))
     } else {
-      p <- ggplot(data.frame(x, y, Y=d$Y), aes(x=x, y=y, color=Y))
-      p <- p + theme_bw(base_size=14)
-      p <- p + theme(axis.text.x=element_text(angle=40, vjust=1, hjust=1))
+      p <- ggplot(data.frame(x, y, Y=d$Y), aes(x=x, y=y, color=Y)) +
+        theme_bw(base_size=14) +
+        theme(axis.text.x=element_text(angle=40, vjust=1, hjust=1))
       if (class(x) == 'factor') {
-        p <- p + geom_boxplot(aes(group=x), alpha=3/6, outlier.size=0, fill='white')
-        p <- p + geom_point(position=position_jitter(w=0.4, h=0), size=1)
+        p <- p + geom_boxplot(aes(group=x), alpha=3/6, outlier.size=0, fill='white') +
+          geom_point(position=position_jitter(w=0.4, h=0), size=1)
       } else {
         p <- p + geom_point(size=1)
       }
diff --git a/chap11/fig11-5.R b/chap11/fig11-5.R
index 52c5759..7a81771 100644
--- a/chap11/fig11-5.R
+++ b/chap11/fig11-5.R
@@ -7,8 +7,8 @@ d <- subset(data.frame(table(d_ori)), Freq >= 1)
 d$PersonID <- as.integer(as.character(d$PersonID))
 d$ItemID <- as.integer(as.character(d$ItemID))
 
-p <- ggplot(data=d, aes(x=ItemID, y=PersonID, fill=Freq))
-p <- p + theme_bw(base_size=22) + theme(axis.text=element_blank(), axis.ticks=element_blank())
-p <- p + geom_point(shape=21, color='white', size=1.5)
-p <- p + scale_fill_gradient(breaks=c(1,5,10), low='grey80', high='black')
+p <- ggplot(data=d, aes(x=ItemID, y=PersonID, fill=Freq)) +
+  theme_bw(base_size=22) + theme(axis.text=element_blank(), axis.ticks=element_blank()) +
+  geom_point(shape=21, color='white', size=1.5) +
+  scale_fill_gradient(breaks=c(1,5,10), low='grey80', high='black')
 ggsave(file='output/fig11-5.png', plot=p, dpi=300, w=8, h=6)
diff --git a/chap11/fig11-6.R b/chap11/fig11-6.R
index 85e1e0b..721ecb9 100644
--- a/chap11/fig11-6.R
+++ b/chap11/fig11-6.R
@@ -1,19 +1,21 @@
+library(dplyr)
 library(ggplot2)
 
 N <- 50
 I <- 120
 d <- read.csv(file='input/data-lda.txt')
-d_cast <- reshape2::dcast(d, PersonID ~ .)
-p <- ggplot(data=d_cast, aes(x=.))
-p <- p + theme_bw(base_size=18)
-p <- p + geom_bar(color='grey5', fill='grey80')
-p <- p + scale_x_continuous(breaks=seq(10,40,10), limits=c(10,40))
-p <- p + labs(x='count by PersonID', y='count')
+
+d_cast <- d %>% group_by(PersonID) %>% summarise(n=n()) %>% ungroup()
+p <- ggplot(data=d_cast, aes(x=n)) +
+  theme_bw(base_size=18) +
+  geom_bar(color='grey5', fill='grey80') +
+  scale_x_continuous(breaks=seq(10,40,10), limits=c(10,40)) +
+  labs(x='count by PersonID', y='count')
 ggsave(file='output/fig11-6-left.png', plot=p, dpi=300, w=4, h=3)
 
-d_cast <- reshape2::dcast(d, ItemID ~ .)
-p <- ggplot(data=d_cast, aes(x=.))
-p <- p + theme_bw(base_size=18)
-p <- p + geom_bar(color='grey5', fill='grey80')
-p <- p + labs(x='count by ItemID', y='count')
+d_cast <- d %>% group_by(ItemID) %>% summarise(n=n()) %>% ungroup()
+p <- ggplot(data=d_cast, aes(x=n)) +
+  theme_bw(base_size=18) +
+  geom_bar(color='grey5', fill='grey80') +
+  labs(x='count by ItemID', y='count')
 ggsave(file='output/fig11-6-right.png', plot=p, dpi=300, w=4, h=3)
diff --git a/chap11/output/fig11-11-left.png b/chap11/output/fig11-11-left.png
index 4ee2253..32de247 100644
Binary files a/chap11/output/fig11-11-left.png and b/chap11/output/fig11-11-left.png differ
diff --git a/chap11/output/fig11-11-right.png b/chap11/output/fig11-11-right.png
index df336d8..e8c7c5a 100644
Binary files a/chap11/output/fig11-11-right.png and b/chap11/output/fig11-11-right.png differ
diff --git a/chap11/output/fig11-11.png b/chap11/output/fig11-11.png
index 390aeec..da56e48 100644
Binary files a/chap11/output/fig11-11.png and b/chap11/output/fig11-11.png differ
diff --git a/chap11/output/fig11-2.png b/chap11/output/fig11-2.png
index d8d8852..456e503 100644
Binary files a/chap11/output/fig11-2.png and b/chap11/output/fig11-2.png differ
diff --git a/chap11/output/fig11-3.png b/chap11/output/fig11-3.png
index ea50c79..3d7a16b 100644
Binary files a/chap11/output/fig11-3.png and b/chap11/output/fig11-3.png differ
diff --git a/chap11/output/fig11-4.png b/chap11/output/fig11-4.png
index 418f3ed..747b10f 100644
Binary files a/chap11/output/fig11-4.png and b/chap11/output/fig11-4.png differ
diff --git a/chap11/output/fig11-5.png b/chap11/output/fig11-5.png
index aca5118..447a40e 100644
Binary files a/chap11/output/fig11-5.png and b/chap11/output/fig11-5.png differ
diff --git a/chap11/output/fig11-6-left.png b/chap11/output/fig11-6-left.png
index 58b35a5..d395636 100644
Binary files a/chap11/output/fig11-6-left.png and b/chap11/output/fig11-6-left.png differ
diff --git a/chap11/output/fig11-6-right.png b/chap11/output/fig11-6-right.png
index e7528b9..7b31ec7 100644
Binary files a/chap11/output/fig11-6-right.png and b/chap11/output/fig11-6-right.png differ
diff --git a/chap11/output/fig11-6.png b/chap11/output/fig11-6.png
index 77c2496..8c1b5d2 100644
Binary files a/chap11/output/fig11-6.png and b/chap11/output/fig11-6.png differ
diff --git a/chap11/run-model11-7.R b/chap11/run-model11-7.R
index 9a1fb0f..ed3fc56 100644
--- a/chap11/run-model11-7.R
+++ b/chap11/run-model11-7.R
@@ -12,5 +12,5 @@ N_mcmc <- length(ms$lp__)
 r <- sapply(1:N_mcmc,
   function(i) cor(ms$lambda[i,], ms$q[i,], method='spearman'))
 quantile(r, prob=c(0.025, 0.25, 0.5, 0.75, 0.975))
-#    2.5%     25%     50%     75%   97.5%
-# -0.7990 -0.6955 -0.6496 -0.6034 -0.4713
\ No newline at end of file
+#       2.5%        25%        50%        75%      97.5% 
+# -0.8063798 -0.6972511 -0.6501928 -0.6052952 -0.4610613 
diff --git a/chap11/run-model11-8.R b/chap11/run-model11-8.R
index 66abea9..0439e82 100644
--- a/chap11/run-model11-8.R
+++ b/chap11/run-model11-8.R
@@ -14,4 +14,4 @@ stanmodel <- stan_model(file='model/model11-8.stan')
 # fit_nuts <- sampling(stanmodel, data=data, seed=123)
 fit_vb <- vb(stanmodel, data=data, seed=123)
 
-save.image('output/result-model11-8.RData')
\ No newline at end of file
+save.image('output/result-model11-8.RData')