Examination of curves for hard-rock sites (Vs30 = 2000) shows that the Campbell (getCampCEUS) follows the older pattern of explicitly requiring change of model ID sign (10 to -10) in an input file in order to use hard-rock coefficients, instead of having a switch on Vs30 that negates the sign if Vs30 > 1500.
Examination of curves for hard-rock sites (Vs30 = 2000) shows that the Campbell (getCampCEUS) follows the older pattern of explicitly requiring change of model ID sign (10 to -10) in an input file in order to use hard-rock coefficients, instead of having a switch on Vs30 that negates the sign if Vs30 > 1500.