Chapter02 {DanielBiostatistics10th}

Chapter 2: Descriptive Statistics

Description

Functions and examples for Chapter 2, Descriptive Statistics.

Usage

print_stats(x, na.rm = TRUE)

print_freqs(x, breaks, include.lowest = TRUE, right = TRUE)

Arguments

x

numeric vector, the observations. In function print_freqs, this argument can also be a factor

na.rm

logical scalar, whether to remove the missing observations (default TRUE)

breaks

numeric vector, see cut.default

include.lowest

logical scalar, default TRUE. See cut.default

right

logical scalar, see cut.default

Details

Function print_freqs prints the (relative) frequencies and cumulative (relative) frequencies, from a numeric input vector, specified interval breaks as well as open/close status of the ends of the intervals.

Function print_stats prints the simple statistics of the input observations, such as sample size, mean, median, (smallest) mode, variance, standard deviation, coefficient of variation (if all observations are non-negative), quartiles, inter-quartile range (IQR), range, skewness and kurtosis. A histogram is also printed.

Value

Function print_freqs returns a freqs object, for which a show method is defined.

Function print_stats does not have a returned value.

See Also

cut.default table cumsum mean.default median.default Mode var sd quantile skewness kurtosis

Examples

library(DanielBiostatistics10th)

# Example 2.2.1; Page 20 (10th ed), Page 19 (11th ed)
head(EXA_C01_S04_01)
class(age <- EXA_C01_S04_01$AGE) # 'integer'
sort(age) # Table 2.2.1

# Example 2.3.1; Page 23 (10th ed); Page 22 (11th ed)
(r231 = print_freqs(age, breaks = seq.int(from=30, to=90, by=10), right = FALSE)) # Table 2.3.2
# The open/close of interval ends is determined by textbook using 30-39, 40-49, etc.

# Example 2.4.1-2.4.6; Page 38-42 (10th ed); Page 30-34 (11th ed)
# Example 2.5.1-2.5.3; Page 44-46 (10th ed); Page 35-41 (11th ed)
print_stats(age) # or some other data input

# Example 2.5.4 (omitted); Page 49 (10th ed), Page 41 (11th ed)

# Example 2.5.5; Page 50 (10th ed)
head(EXA_C02_S05_05)
boxplot(EXA_C02_S05_05$GRF, main = c('Example 2.5.5 (10th ed)'))
print_stats(EXA_C02_S05_05$GRF)
print_freqs(EXA_C02_S05_05$GRF, breaks = seq.int(10, 45, by = 5))