class-activity-1.Rmd

---
title: "class activity 1"
author: "Charles Lang"
date: "9/24/2018"
output: html_document
---

```{r}
#3.
library(dplyr)
library(tidyr)

#4.
DF1 <- read.csv("swirl-data.csv")

#5.
DF2 <- select(DF1, hash, lesson_name, attempt)

#6.
DF3 <- DF2 %>% group_by(hash, lesson_name) %>% summarise(attempt = sum(attempt))

#7./8.
DF3b <- spread(DF3, lesson_name, attempt)

#9.
DF4 <- select(DF1, hash, lesson_name, correct)

#10.
DF4$correct <- ifelse(DF4$correct == TRUE, 1, 
                      ifelse(DF4$correct == NA, NA, 0))

#11.
DF5 <- DF4 %>% group_by(hash, lesson_name) %>% summarise(mean.correct = mean(correct, na.rm = TRUE))

# Extra Credit

DF6 <- select(DF1, correct, datetime)

DF6$correct <- ifelse(DF6$correct == TRUE, 1, 0)

DF6$datetime <- as.POSIXlt(DF6$datetime, origin = "1970-01-01 00:00.00 UTC")

DF6$datetime <- strftime(DF6$datetime, format="%b:%e")

DF7 <- DF6 %>% group_by(datetime) %>% summarise(av.correct = mean(correct, na.rm = TRUE))
```