Descriptive statistics for one or several variables
descr.RdFunction computes descriptive statistics for one variable or several variables within a data frame.
Arguments
- variable
one variable or a data.frame with several variables
- na
optional values with should be considered a missing values
- p.weights
optional: vector with individual weights if weighted statistics should be computed
- na.rm
logical: should missings be removed prior to estimation?
- verbose
logical: Print messages to console?
Value
a data frame with the following columns
- N
number of observations
- N.valid
number of non-missing observations
- Missing
number of missings
- Minimum
minimum of numeric variables
- Maximum
maximum of numeric variables
- Sum
sum of numeric variables
- Mean
arithmetic mean of numeric variables
- std.err
standard error of the arithmetic mean. Note: for weighted means, standard error is estimated according to Cochran (1977): \(sigma_x^2=n/((n-1)*w_s^2)*Sigma(w_i^2*(x_i-x))\).
- sig
p value
- Median
median of numeric variables
- SD
standard deviation of numeric variables
- Var
variance of numeric variables
Examples
data(mtcars)
descr(mtcars)
#> N N.valid Missing Minimum Maximum Sum Mean std.err
#> mpg 32 32 0 10.400 33.900 642.900 20.090625 1.06542396
#> cyl 32 32 0 4.000 8.000 198.000 6.187500 0.31570933
#> disp 32 32 0 71.100 472.000 7383.100 230.721875 21.90947271
#> hp 32 32 0 52.000 335.000 4694.000 146.687500 12.12031731
#> drat 32 32 0 2.760 4.930 115.090 3.596563 0.09451874
#> wt 32 32 0 1.513 5.424 102.952 3.217250 0.17296847
#> qsec 32 32 0 14.500 22.900 571.160 17.848750 0.31588992
#> vs 32 32 0 0.000 1.000 14.000 0.437500 0.08909831
#> am 32 32 0 0.000 1.000 13.000 0.406250 0.08820997
#> gear 32 32 0 3.000 5.000 118.000 3.687500 0.13042656
#> carb 32 32 0 1.000 8.000 90.000 2.812500 0.28552971
#> sig Median SD Var
#> mpg 1.526151e-18 19.200 6.0269481 3.632410e+01
#> cyl 5.048147e-19 6.000 1.7859216 3.189516e+00
#> disp 9.189065e-12 196.300 123.9386938 1.536080e+04
#> hp 2.794134e-13 123.000 68.5628685 4.700867e+03
#> drat 1.377586e-27 3.695 0.5346787 2.858814e-01
#> wt 2.257406e-18 3.325 0.9784574 9.573790e-01
#> qsec 7.790282e-33 17.710 1.7869432 3.193166e+00
#> vs 2.776961e-05 0.000 0.5040161 2.540323e-01
#> am 6.632258e-05 0.000 0.4989909 2.489919e-01
#> gear 1.066949e-23 4.000 0.7378041 5.443548e-01
#> carb 4.590930e-11 2.000 1.6152000 2.608871e+00