Section 31 Mean & Confidence Interval

31.1 Example 1

# data

DF <- data.frame(
  trt = factor(c(1, 1, 2, 2)),
  resp = c(1, 5, 3, 4),
  group = factor(c(1, 2, 1, 2)),
  upper = c(1.1, 5.3, 3.3, 4.2),
  lower = c(0.8, 4.6, 2.4, 3.6)
)


# geom_point

g <- ggplot(data=DF, mapping=aes(trt, resp, colour = group))
g <- g + geom_point(size=5)
g

# geom_errorbar

g <- ggplot(data=DF, mapping=aes(trt, resp, colour = group))
g <- g + geom_point(size=5)
g <- g + geom_errorbar(aes(ymin = lower, ymax = upper), width = 0.2)
g

# geom_crossbar

g <- ggplot(data=DF, mapping=aes(trt, resp, colour = group))
g <- g + geom_crossbar(aes(ymin = lower, ymax = upper), width = 0.2)
g

# Draw lines connecting group means
g <- ggplot(data=DF, mapping=aes(trt, resp, colour = group))
g <- g + geom_point(size=5)
g <- g + geom_errorbar(aes(ymin = lower, ymax = upper), width = 0.2)
g <- g + geom_line(aes(group = group))
g + theme_bw()

31.2 Example 2

# data

DF <- data.frame(
  trt = factor(c(1, 1, 2, 2)),
  resp = c(1, 5, 3, 4),
  group = factor(c(1, 2, 1, 2)),
  upper = c(1.1, 5.3, 3.3, 4.2),
  lower = c(0.8, 4.6, 2.4, 3.6)
)


# Option 1: geom_bar

g <- ggplot(data=DF, mapping=aes(trt, resp, fill = group))
g <- g + geom_bar(position='dodge', stat='identity')
g

# Option 2: geom_bar

g <- ggplot(data=DF, mapping=aes(trt, resp, fill = group))
g <- g + geom_bar(position=position_dodge(), stat='identity')
g

# geom_errorbar

g <- ggplot(data=DF, mapping=aes(trt, resp, fill = group))
g <- g + geom_bar(position=position_dodge(), stat='identity')
g <- g + geom_errorbar(aes(ymin = lower, ymax = upper), width = 0.2)
g

# geom_errorbar position

g <- ggplot(data=DF, mapping=aes(trt, resp, fill = group))
g <- g + geom_bar(position=position_dodge(), stat='identity')
g <- g + geom_errorbar(aes(ymin = lower, ymax = upper), 
                       width = 0.5, position=position_dodge(width=0.9))
g + theme_bw()