Create 02_recitation.R

code/02_recitation.R

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+# Lousiana Parishes ########################################
+
+## Load packages ###########################
+library(dplyr)
+library(readr)
+
+## Data ###########################
+# Read in stuff
+la = read_csv("workshops/la_parishes.csv")
+
+## Statistics ###########################
+
+# Percentage of houses damaged by the hurricane
+la$pc_damage
+
+sigma = la$pc_damage %>% sd()
+# The percentage of houses damaged by the hurricane varies from the average by ~20 (units)
+mu = la$pc_damage %>% mean()
+# The average county had 51% of houses damaged
+n = la$pc_damage %>% length()
+
+mu + sigma
+mu - sigma
+
+# mu + sigma*3
+# mu - sigma*3
+
+
+# Coefficient of Variation 
+sigma / mu
+
+# Standard Error
+se = sigma / sqrt(n)
+
+# Confidence Interval
+mu + se*1.96
+mu - se*1.96
+
+
+mu
+
+
+rm(list = ls())
+
+
+
+# Quality Control with Cheese ##########################
+
+
+## Packages ########################
+library(dplyr)
+
+## Data ###########################
+a = c(50, 70, 125, 235, 230, 200, 180, 260, 300, 500, 275, 280)
+b = c(300, 380, 250, 50, 55, 57, 60, 65, 100, 150, 250, 200, 150, 175, 225, 200, 225, 250)
+c= c(400, 300, 400, 300, 350, 200, 250, 300, 330, 375)
+
+
+## Mean
+## Std
+## Coefficient of Variation / Standard Error
+
+# Tell me who you'd buy your cheese from and why.
+
+
+mean(a)
+mean(b)
+mean(c)
+
+data = data.frame(
+  type = c("a", "b", "c"),
+  mu = c( mean(a), mean(b), mean(c) ),
+  sigma = c( sd(a), sd(b), sd(c)  ),
+  n = c( length(a), length(b), length(c) )
+)
+
+data$cv = data$sigma / data$mu
+data$se = data$sigma / sqrt(data$n)
+
+data$upper = data$mu + data$sigma
+data$lower = data$mu - data$sigma
+data
+
+library(ggplot2)
+
+ggplot() +
+  geom_point(data = data, mapping = aes(x = mu, y = type, color = "Mean")) +
+  geom_point(data = data, mapping = aes(x = lower, y = type, color = "-1 sigma")) +
+  geom_point(data = data, mapping = aes(x = upper, y = type, color = "+1 sigma")) +
+  labs(x = "Time to Failure (hours)")
+
+
+