get.vaTer = function(Pc, VRT, MRT, s=.1)
{
    s2 = s^2
    # The default value for the scaling parameter s equals .1

    if (Pc == 0)
        cat("Oops, Pc == 0!\n")
    if (Pc == 0.5)
        cat("Oops, Pc == .5!\n")
    if (Pc == 1)
        cat("Oops, Pc == 1!\n")
    # If Pc equals 0, .5, or 1, the method will not work, and
    # an edge-correction is required.

    L = qlogis(Pc)
    # The function "qlogis" calculates the logit.
    x = L*(L*Pc^2 - L*Pc + Pc - 0.5)/VRT
    v = sign(Pc-0.5)*s*x^(1/4)
    # This gives drift rate.

    a = s2*qlogis(Pc)/v
    # This gives boundary separation.

    y   = -v*a/s2
    MDT = (a/(2*v))*(1-exp(y))/(1+exp(y))
    Ter = MRT-MDT
    # This gives nondecision time.

    return(list(v, a, Ter))
}