code for help teaching chs. 11 and 12 of FPP

chs. 11-12 code

# data loading and tidying
##########################
# Note: we haven't talked about how to do this, and I don't expect you to
# understand the code below. But trust me that it grabs the data you submitted
# in the forms and loads it as a data frame.
library(googlesheets)  # used to load the google sheet data
sheet <- gs_key("1mJVzIpolvJ5XPROMCXg1A5iU_mlWXwHBlXQwG5t_QVk") # register google sheet
bodies <- gs_read(sheet)  # load sheet
saveRDS(bodies, "data/bodies.rds")  # save the former google sheet as a .rds
rm(sheet, bodies)  # remove the sheet to have a clean workspace
# done with tidying  
###################  

# load newly saved data frame
bodies <- readRDS("data/bodies.rds")

# quick look at data
tibble::glimpse(bodies)

# calculate aveages and SDs for each variable
apply(bodies, 2, mean)
apply(bodies, 2, sd)

# calculate correlations
num_bodies <- dplyr::select(bodies, -time, -sex)
cor(dplyr::select(bodies, -time, -sex))

# plot of forearm length and height
gg1 <- ggplot(bodies, aes(x = forearm, y = height)) + 
  geom_point() + 
  labs(title = "Scatterplot of Forearm Length and Height")

# plot of hand span and height
gg2 <- ggplot(bodies, aes(x = hand, y = height, color = sex)) + 
  geom_point() + 
  labs(title = "Scatterplot of Hand Span and Height")

# plot of head circumference and height
gg3 <- ggplot(bodies, aes(x = head, y = height, color = sex)) + 
  geom_point() + 
  labs(title = "Scatterplot of Head Circumference and Height")

# combine the three ggplots
gridExtra::grid.arrange(gg1, gg2, gg3)

# plot forearms and height with SD line
slope <- sd(bodies$height)/sd(bodies$forearm)
intercept <- mean(bodies$height) - mean(bodies$forearm)*slope
gg1 + geom_abline(slope = slope, intercept = intercept) + 
  geom_smooth(method = "lm", linetype = "dashed", color= "red", se = FALSE)