[MRG] GPU bugs solve (#288)

* gpus tests now passing

* pep8 compliance

* GPU tests succeeding even if b has rank higher than 1

Co-authored-by: Rémi Flamary <remi.flamary@gmail.com>

Author: ncassereau

ot/bregman.py

@@ -312,7 +312,7 @@ def sinkhorn_knopp(a, b, M, reg, numItermax=1000,
     numItermax : int, optional
         Max number of iterations
     stopThr : float, optional
-        Stop threshol on error (>0)
+        Stop threshold on error (>0)
     verbose : bool, optional
         Print information along iterations
     log : bool, optional

ot/gpu/bregman.py

@@ -54,7 +54,7 @@ def sinkhorn_knopp(a, b, M, reg, numItermax=1000, stopThr=1e-9,
     numItermax : int, optional
         Max number of iterations
     stopThr : float, optional
-        Stop threshol on error (>0)
+        Stop threshold on error (>0)
     verbose : bool, optional
         Print information along iterations
     log : bool, optional
@@ -148,13 +148,15 @@ def sinkhorn_knopp(a, b, M, reg, numItermax=1000, stopThr=1e-9,
             # we can speed up the process by checking for the error only all
             # the 10th iterations
             if nbb:
-                err = np.sum((u - uprev)**2) / np.sum((u)**2) + \
-                    np.sum((v - vprev)**2) / np.sum((v)**2)
+                err = np.sqrt(
+                    np.sum((u - uprev)**2) / np.sum((u)**2)
+                    + np.sum((v - vprev)**2) / np.sum((v)**2)
+                )
             else:
                 # compute right marginal tmp2= (diag(u)Kdiag(v))^T1
                 tmp2 = np.sum(u[:, None] * K * v[None, :], 0)
                 #tmp2=np.einsum('i,ij,j->j', u, K, v)
-                err = np.linalg.norm(tmp2 - b)**2  # violation of marginal
+                err = np.linalg.norm(tmp2 - b)  # violation of marginal
             if log:
                 log['err'].append(err)
 

ot/gpu/da.py

@@ -120,7 +120,7 @@ def sinkhorn_lpl1_mm(a, labels_a, b, M, reg, eta=0.1, numItermax=10,
     labels_a2 = cp.asnumpy(labels_a)
     classes = npp.unique(labels_a2)
     for c in classes:
-        idxc, = utils.to_gpu(npp.where(labels_a2 == c))
+        idxc = utils.to_gpu(*npp.where(labels_a2 == c))
         indices_labels.append(idxc)
 
     W = np.zeros(M.shape)