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-rw-r--r--ot/lp/emd_wrap.pyx42
1 files changed, 36 insertions, 6 deletions
diff --git a/ot/lp/emd_wrap.pyx b/ot/lp/emd_wrap.pyx
index 2b6c495..c0d7128 100644
--- a/ot/lp/emd_wrap.pyx
+++ b/ot/lp/emd_wrap.pyx
@@ -20,6 +20,9 @@ import warnings
cdef extern from "EMD.h":
int EMD_wrap(int n1,int n2, double *X, double *Y,double *D, double *G, double* alpha, double* beta, double *cost, int maxIter)
+ int EMD_wrap_return_sparse(int n1, int n2, double *X, double *Y, double *D,
+ long *iG, long *jG, double *G, long * nG,
+ double* alpha, double* beta, double *cost, int maxIter)
cdef enum ProblemType: INFEASIBLE, OPTIMAL, UNBOUNDED, MAX_ITER_REACHED
@@ -39,7 +42,7 @@ def check_result(result_code):
@cython.boundscheck(False)
@cython.wraparound(False)
-def emd_c(np.ndarray[double, ndim=1, mode="c"] a, np.ndarray[double, ndim=1, mode="c"] b, np.ndarray[double, ndim=2, mode="c"] M, int max_iter):
+def emd_c(np.ndarray[double, ndim=1, mode="c"] a, np.ndarray[double, ndim=1, mode="c"] b, np.ndarray[double, ndim=2, mode="c"] M, int max_iter, bint dense):
"""
Solves the Earth Movers distance problem and returns the optimal transport matrix
@@ -72,7 +75,8 @@ def emd_c(np.ndarray[double, ndim=1, mode="c"] a, np.ndarray[double, ndim=1, mod
max_iter : int
The maximum number of iterations before stopping the optimization
algorithm if it has not converged.
-
+ dense : bool
+ Return a sparse transport matrix if set to False
Returns
-------
@@ -82,12 +86,19 @@ def emd_c(np.ndarray[double, ndim=1, mode="c"] a, np.ndarray[double, ndim=1, mod
"""
cdef int n1= M.shape[0]
cdef int n2= M.shape[1]
+ cdef int nmax=n1+n2-1
+ cdef int result_code = 0
+ cdef int nG=0
cdef double cost=0
- cdef np.ndarray[double, ndim=2, mode="c"] G=np.zeros([n1, n2])
cdef np.ndarray[double, ndim=1, mode="c"] alpha=np.zeros(n1)
cdef np.ndarray[double, ndim=1, mode="c"] beta=np.zeros(n2)
+ cdef np.ndarray[double, ndim=2, mode="c"] G=np.zeros([0, 0])
+
+ cdef np.ndarray[double, ndim=1, mode="c"] Gv=np.zeros(0)
+ cdef np.ndarray[long, ndim=1, mode="c"] iG=np.zeros(0,dtype=np.int)
+ cdef np.ndarray[long, ndim=1, mode="c"] jG=np.zeros(0,dtype=np.int)
if not len(a):
a=np.ones((n1,))/n1
@@ -95,10 +106,29 @@ def emd_c(np.ndarray[double, ndim=1, mode="c"] a, np.ndarray[double, ndim=1, mod
if not len(b):
b=np.ones((n2,))/n2
- # calling the function
- cdef int result_code = EMD_wrap(n1, n2, <double*> a.data, <double*> b.data, <double*> M.data, <double*> G.data, <double*> alpha.data, <double*> beta.data, <double*> &cost, max_iter)
+ if dense:
+ # init OT matrix
+ G=np.zeros([n1, n2])
+
+ # calling the function
+ result_code = EMD_wrap(n1, n2, <double*> a.data, <double*> b.data, <double*> M.data, <double*> G.data, <double*> alpha.data, <double*> beta.data, <double*> &cost, max_iter)
+
+ return G, cost, alpha, beta, result_code
+
+
+ else:
+
+ # init sparse OT matrix
+ Gv=np.zeros(nmax)
+ iG=np.zeros(nmax,dtype=np.int)
+ jG=np.zeros(nmax,dtype=np.int)
+
+
+ result_code = EMD_wrap_return_sparse(n1, n2, <double*> a.data, <double*> b.data, <double*> M.data, <long*> iG.data, <long*> jG.data, <double*> Gv.data, <long*> &nG, <double*> alpha.data, <double*> beta.data, <double*> &cost, max_iter)
+
+
+ return Gv[:nG], iG[:nG], jG[:nG], cost, alpha, beta, result_code
- return G, cost, alpha, beta, result_code
@cython.boundscheck(False)