efficiency_plot: the aim of the script is to check the mean values of a turbine efficiency, given a fixed correlation matrix for pressure and temperatures.
efficiency_variance: the aim is the calculation of the square root of the variance of turbine efficiency, given a fixed matrix of correlation between temperatures and pressures.
mapping points: checks the variations of efficiency when points are mapped from physical to a new standard space (an inverse Nataf transformation has been used)
order_check: how the efficiency order may change when we map the points with an inverse Nataf transformation?