This function contains Fleishman's third-order polynomial transformation equations (10.1007/BF02293811). It is used in
find_constants to find the constants c1, c2, and c3 (c0 = -c2) that satisfy the
equations given skewness and standardized kurtosis values. It can be used to verify a set of constants satisfy
the equations. Note that there exist solutions that yield invalid power method pdfs (see
power_norm_corr, pdf_check).
This function would not ordinarily be called by the user.
Usage
fleish(c, a)
Arguments
c
a vector of constants c1, c2, c3; note that find_constants returns c0, c1, c2, c3
a
a vector c(skewness, standardized kurtosis)
Value
a list of length 3; if the constants satisfy the equations, returns 0 for all list elements
References
Fleishman AI (1978). A Method for Simulating Non-normal Distributions. Psychometrika, 43, 521-532. 10.1007/BF02293811.
Headrick TC, Sawilowsky SS (1999). Simulating Correlated Non-normal Distributions: Extending the Fleishman Power
Method. Psychometrika, 64, 25-35. 10.1007/BF02294317.