metagear (version 0.6)

random_RR: Random generation of log response ratio (RR) effect sizes.

Description

Generates random log response ratios and their variances (Hedges et al. 1999). NOTE: samples from a log-normal distribution to generate non-negative control and treatment means (following Lajeunesse 2015).

Usage

random_RR(K, X_t, var_t, N_t, X_c, var_c, N_c)

Arguments

K

Number of effect sizes to generate.

X_t

The population mean (mu) of the (t)reatment group (numerator of ratio).

var_t

The population variance of the treatment group mean.

N_t

The number of samples of the treatment mean. When a non-negative integer, all treatment means will be estimated using the same N. A vector of unequal N's can also be taken; if so, K will be ignored and the number of randomly generated means will equal the length of that vector, and each mean will be based on each N within the vector.

X_c

The population mean (mu) of the (c)ontrol group (denominator of ratio).

var_c

The population variance of the control group mean.

N_c

The number of samples of the control mean. When a non-negative integer, all control means will be estimated using the same N. A vector of unequal N's can also be taken; if so, K will be ignored and the number of randomly generated means will equal the length of that vector, and each mean will be based on each N within the vector.

Value

A data table with columns of random effect sizes (RR) and their variances.

References

Hedges, L.V., J. Gurevitch, and P.S. Curtis. 1999. The meta-analysis of response ratios in experimental ecology. Ecology 80: 1150-1156.

Lajeunesse, M.J. 2015. Bias and correction for the log response ratio used in ecological meta-analysis. Ecology.

Examples

# NOT RUN {
   random_RR(K = 5, X_t = 25, var_t = 1, N_t = 15, X_c = 10, var_c = 1, N_c = 15)

# }