Cohen's d
Description
Calculate Cohen's d from raw data or a call to t_test
/t.test
.
Usage
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17  cohens_d(...)
## Default S3 method:
cohens_d(x, y = NULL, paired = FALSE, corr = c("none",
"hedges_g", "glass_delta"), na.rm = FALSE, ...)
## S3 method for class 'data.frame'
cohens_d(data, dv, iv, paired = FALSE, corr = c("none",
"hedges_g", "glass_delta"), na.rm = FALSE, ...)
## S3 method for class 'formula'
cohens_d(formula, data, paired = FALSE, corr = c("none",
"hedges_g", "glass_delta"), na.rm = FALSE, ...)
## S3 method for class 'htest'
cohens_d(ttest, corr = c("none", "hedges_g", "glass_delta"),
...)

Arguments
... 
Further arguments passed to methods. 
x 
A (nonempty) numeric vector of data values. 
y 
An optional (nonempty) numeric vector of data values. 
paired 
A logical indicating whether Cohen's d should be calculated for a paired sample or two independent samples (default). Ignored when calculating Cohen's for one sample. 
corr 
Character specifying the correction applied to calculation of the
effect size: 
na.rm 
Logical. Should missing values be removed? 
data 
A data frame containing either the variables in the formula

dv 
Character indicating the name of the column in 
iv 
Character indicating the name of the column in 
formula 
A formula of the form 
ttest 
An object of class 
Details
To calculate Cohen's d from summary statistics (M, SD, ..) use cohens_d_.
References
Lakens, D. (2013). Calculating and reporting effect sizes to facilitate cumulative science: a practical primer for ttests and ANOVAs. Frontiers in Psychology, 4, 863. doi:10.3389/fpsyg.2013.00863
Examples
1 2 3 4 5 6 7 8 9 10 11 12  # Calculate from raw data
cohens_d(c(10, 15, 11, 14, 17), c(22, 18, 23, 25, 20))
# Methods when working with data frames
cohens_d(sleep, dv = extra, iv = group, paired = TRUE)
# or
cohens_d(sleep, dv = "extra", iv = "group", paired = TRUE)
# formula interface
cohens_d(extra ~ group, sleep, paired = TRUE)
# Or pass a call to t_test or t.test
cohens_d(t_test(extra ~ group, sleep, paired = TRUE))
