This is an updated and expanded version of the mammals sleep dataset. Updated sleep times and weights were taken from V. M. Savage and G. B. West. A quantitative, theoretical framework for understanding mammalian sleep. Proceedings of the National Academy of Sciences, 104 (3):1051-1056, 2007. msleep https://ggplot2.tidyverse.org/reference/msleep.html
library(downloader)
url="https://raw.githubusercontent.com/genomicsclass/dagdata/master/inst/extdata/msleep_ggplot2.csv"
filename <- basename(url)
download(url,filename)
if (!file.exists(filename)) download(url, destfile=filename)## [1] "data.frame"## 'data.frame': 83 obs. of 11 variables:
## $ name : Factor w/ 83 levels "African elephant",..: 12 57 52 36 17 77 55 81 21 67 ...
## $ genus : Factor w/ 77 levels "Acinonyx","Aotus",..: 1 2 3 4 5 6 7 8 9 10 ...
## $ vore : Factor w/ 4 levels "carni","herbi",..: 1 4 2 4 2 2 1 NA 1 2 ...
## $ order : Factor w/ 19 levels "Afrosoricida",..: 3 15 17 19 2 14 3 17 3 2 ...
## $ conservation: Factor w/ 6 levels "cd","domesticated",..: 4 NA 5 4 2 NA 6 NA 2 4 ...
## $ sleep_total : num 12.1 17 14.4 14.9 4 14.4 8.7 7 10.1 3 ...
## $ sleep_rem : num NA 1.8 2.4 2.3 0.7 2.2 1.4 NA 2.9 NA ...
## $ sleep_cycle : num NA NA NA 0.133 0.667 ...
## $ awake : num 11.9 7 9.6 9.1 20 9.6 15.3 17 13.9 21 ...
## $ brainwt : num NA 0.0155 NA 0.00029 0.423 NA NA NA 0.07 0.0982 ...
## $ bodywt : num 50 0.48 1.35 0.019 600 ...Use the filter function to select only the primates. How many animals in the table are primates? Hint: the nrow function gives you the number of rows of a data frame or matrix.
Use the select function to extract the sleep (total) for the primates. What class is this object? Hint: use %>% to pipe the results of the filter function to select.
library(dplyr)##
## Attaching package: 'dplyr'## The following objects are masked from 'package:stats':
##
## filter, lag## The following objects are masked from 'package:base':
##
## intersect, setdiff, setequal, unionprim_sleep <- filter(dat2, order=="Primates")%>%select(sleep_total)%>%classNow we want to calculate the average amount of sleep for primates (the average of the numbers computed above). One challenge is that the mean function requires a vector so, if we simply apply it to the output above, we get an error. Look at the help file for unlist and use it to compute the desired average.
prim_sleep_mean <- filter(dat2, order=="Primates")%>%select(sleep_total)
mean(prim_sleep_mean$sleep_total)## [1] 10.5For the last exercise, we could also use the dplyr summarize function. We have not introduced this function, but you can read the help file and repeat exercise 5, this time using just filter and summarize to get the answer.