diff --git a/tensorflow_privacy/privacy/analysis/gdp_accountant.py b/tensorflow_privacy/privacy/analysis/gdp_accountant.py index 5ac82f8..d7133b4 100644 --- a/tensorflow_privacy/privacy/analysis/gdp_accountant.py +++ b/tensorflow_privacy/privacy/analysis/gdp_accountant.py @@ -30,32 +30,32 @@ from scipy import optimize # Target delta:delta def compute_mu_uniform(epoch, noise_multi, N, batch_size): - '''Compute mu from uniform subsampling''' + '''Compute mu from uniform subsampling.''' T = epoch*N/batch_size c = batch_size*np.sqrt(T)/N return np.sqrt(2)*c*np.sqrt(np.exp(noise_multi**(-2))*\ norm.cdf(1.5/noise_multi)+3*norm.cdf(-0.5/noise_multi)-2) -def compute_mu_Poisson(epoch, noise_multi, N, batch_size): - '''Compute mu from Poisson subsampling''' +def compute_mu_poisson(epoch, noise_multi, N, batch_size): + '''Compute mu from Poisson subsampling.''' T = epoch*N/batch_size return np.sqrt(np.exp(noise_multi**(-2))-1)*np.sqrt(T)*batch_size/N def delta_eps_mu(eps, mu): - '''Dual between mu-GDP and (epsilon, delta)-DP''' + '''Compute dual between mu-GDP and (epsilon, delta)-DP.''' return norm.cdf(-eps/mu+mu/2)-np.exp(eps)*norm.cdf(-eps/mu-mu/2) def eps_from_mu(mu, delta): - '''inverse Dual''' + '''Compute epsilon from mu given delta via inverse dual.''' def f(x): - '''reversely solving dual''' + '''Reversely solve dual by matching delta.''' return delta_eps_mu(x, mu) - delta return optimize.root_scalar(f, bracket=[0, 500], method='brentq').root def compute_eps_uniform(epoch, noise_multi, N, batch_size, delta): - '''inverse Dual of uniform subsampling''' + '''Compute epsilon given delta from inverse dual of uniform subsampling.''' return eps_from_mu(compute_mu_uniform(epoch, noise_multi, N, batch_size), delta) -def compute_eps_Poisson(epoch, noise_multi, N, batch_size, delta): - '''inverse Dual of Poisson subsampling''' - return eps_from_mu(compute_mu_Poisson(epoch, noise_multi, N, batch_size), delta) +def compute_eps_poisson(epoch, noise_multi, N, batch_size, delta): + '''Compute epsilon given delta from inverse dual of Poisson subsampling.''' + return eps_from_mu(compute_mu_poisson(epoch, noise_multi, N, batch_size), delta)