def _ptransform(p):
 return ((-1.0) / (1.0 + (1.5 * _phi(((1.0 + p) / 2.0)))))

def _ptransform ( p ) : return ( ( - 1.0 ) / ( 1.0 + ( 1.5 * _phi ( ( ( 1.0 + p ) / 2.0 ) ) ) ) )
function for p-value abcissa transformation .