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-rw-r--r--ot/lp/cvx.py29
1 files changed, 17 insertions, 12 deletions
diff --git a/ot/lp/cvx.py b/ot/lp/cvx.py
index 3913ae5..91a5922 100644
--- a/ot/lp/cvx.py
+++ b/ot/lp/cvx.py
@@ -27,7 +27,7 @@ def scipy_sparse_to_spmatrix(A):
def barycenter(A, M, weights=None, verbose=False, log=False, solver='interior-point'):
- """Compute the entropic regularized wasserstein barycenter of distributions A
+ """Compute the Wasserstein barycenter of distributions A
The function solves the following optimization problem [16]:
@@ -149,7 +149,7 @@ def barycenter(A, M, weights=None, verbose=False, log=False, solver='interior-po
-def free_support_barycenter(data_positions, data_weights, X_init, b_init, lamda, numItermax=100, stopThr=1e-5, verbose=False, log=False, **kwargs):
+def free_support_barycenter(measures_locations, measures_weights, X_init, b_init, weights=None, numItermax=100, stopThr=1e-6, verbose=False):
"""
Solves the free support (locations of the barycenters are optimized, not the weights) Wasserstein barycenter problem (i.e. the weighted Frechet mean for the 2-Wasserstein distance)
@@ -170,7 +170,7 @@ def free_support_barycenter(data_positions, data_weights, X_init, b_init, lamda,
Initialization of the support locations (on k atoms) of the barycenter
b_init : (k,) np.ndarray
Initialization of the weights of the barycenter (non-negatives, sum to 1)
- lambda : (k,) np.ndarray
+ weights : (k,) np.ndarray
Initialization of the coefficients of the barycenter (non-negatives, sum to 1)
numItermax : int, optional
@@ -200,25 +200,30 @@ def free_support_barycenter(data_positions, data_weights, X_init, b_init, lamda,
d = X_init.shape[1]
k = b_init.size
- N = len(data_positions)
+ N = len(measures_locations)
+
+ if not weights:
+ weights = np.ones((N,))/N
X = X_init
- displacement_square_norm = 1e3
+ displacement_square_norm = stopThr+1.
while ( displacement_square_norm > stopThr and iter_count < numItermax ):
T_sum = np.zeros((k, d))
- for (data_positions_i, data_weights_i) in zip(data_positions, data_weights):
- M_i = ot.dist(X, data_positions_i)
- T_i = ot.emd(b_init, data_weights_i, M_i)
- T_sum += np.reshape(1. / b_init, (-1, 1)) * np.matmul(T_i, data_positions_i)
+ for (measure_locations_i, measure_weights_i, weight_i) in zip(measures_locations, measures_weights, weights.tolist()):
+
+ M_i = ot.dist(X, measure_locations_i)
+ T_i = ot.emd(b_init, measure_weights_i, M_i)
+ T_sum += np.reshape(1. / b_init, (-1, 1)) * np.matmul(T_i, measure_locations_i)
- X_previous = X
- X = T_sum / N
+ displacement_square_norm = np.sum(np.square(X-T_sum))
+ X = T_sum
- displacement_square_norm = np.sum(np.square(X-X_previous))
+ if verbose:
+ print('iteration %d, displacement_square_norm=%f\n', iter_count, displacement_square_norm)
iter_count += 1