diff options
Diffstat (limited to 'ot/lp/emd_wrap.pyx')
| -rw-r--r-- | ot/lp/emd_wrap.pyx | 101 |
1 files changed, 59 insertions, 42 deletions
diff --git a/ot/lp/emd_wrap.pyx b/ot/lp/emd_wrap.pyx index 4febb32..7056e0e 100644 --- a/ot/lp/emd_wrap.pyx +++ b/ot/lp/emd_wrap.pyx @@ -1,9 +1,12 @@ # -*- coding: utf-8 -*- """ -Created on Thu Sep 11 08:42:08 2014 - -@author: rflamary +Cython linker with C solver """ + +# Author: Remi Flamary <remi.flamary@unice.fr> +# +# License: MIT License + import numpy as np cimport numpy as np @@ -12,47 +15,50 @@ cimport cython cdef extern from "EMD.h": - void EMD_wrap(int n1,int n2, double *X, double *Y,double *D, double *G, double *cost, - double* alpha, double* beta, int max_iter) + int EMD_wrap(int n1,int n2, double *X, double *Y,double *D, double *G, double* alpha, double* beta, double *cost, int max_iter) + cdef enum ProblemType: INFEASIBLE, OPTIMAL, UNBOUNDED @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 maxiter): +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): """ Solves the Earth Movers distance problem and returns the optimal transport matrix - + gamm=emd(a,b,M) - + .. math:: - \gamma = arg\min_\gamma <\gamma,M>_F - + \gamma = arg\min_\gamma <\gamma,M>_F + s.t. \gamma 1 = a - - \gamma^T 1= b - + + \gamma^T 1= b + \gamma\geq 0 where : - + - M is the metric cost matrix - a and b are the sample weights - + Parameters ---------- a : (ns,) ndarray, float64 - source histogram + source histogram b : (nt,) ndarray, float64 target histogram M : (ns,nt) ndarray, float64 - loss matrix - - + loss matrix + max_iter : int + The maximum number of iterations before stopping the optimization + algorithm if it has not converged. + + Returns ------- gamma: (ns x nt) ndarray Optimal transportation matrix for the given parameters - + """ cdef int n1= M.shape[0] cdef int n2= M.shape[1] @@ -61,7 +67,8 @@ def emd_c( np.ndarray[double, ndim=1, mode="c"] a,np.ndarray[double, ndim=1, mod 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) - + + if not len(a): a=np.ones((n1,))/n1 @@ -69,47 +76,54 @@ def emd_c( np.ndarray[double, ndim=1, mode="c"] a,np.ndarray[double, ndim=1, mod b=np.ones((n2,))/n2 # calling the function - EMD_wrap(n1,n2,<double*> a.data,<double*> b.data,<double*> M.data,<double*> G.data, - <double*> alpha.data, <double*> beta.data, <double*> &cost, maxiter) + cdef int resultSolver = 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 resultSolver != OPTIMAL: + if resultSolver == INFEASIBLE: + print("Problem infeasible. Try to increase numItermax.") + elif resultSolver == UNBOUNDED: + print("Problem unbounded") return G, alpha, beta @cython.boundscheck(False) @cython.wraparound(False) -def emd2_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 maxiter): +def emd2_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): """ Solves the Earth Movers distance problem and returns the optimal transport loss - + gamm=emd(a,b,M) - + .. math:: - \gamma = arg\min_\gamma <\gamma,M>_F - + \gamma = arg\min_\gamma <\gamma,M>_F + s.t. \gamma 1 = a - - \gamma^T 1= b - + + \gamma^T 1= b + \gamma\geq 0 where : - + - M is the metric cost matrix - a and b are the sample weights - + Parameters ---------- a : (ns,) ndarray, float64 - source histogram + source histogram b : (nt,) ndarray, float64 target histogram M : (ns,nt) ndarray, float64 - loss matrix - - + loss matrix + max_iter : int + The maximum number of iterations before stopping the optimization + algorithm if it has not converged. + + Returns ------- gamma: (ns x nt) ndarray Optimal transportation matrix for the given parameters - + """ cdef int n1= M.shape[0] cdef int n2= M.shape[1] @@ -119,16 +133,19 @@ def emd2_c( np.ndarray[double, ndim=1, mode="c"] a,np.ndarray[double, ndim=1, mo cdef np.ndarray[double, ndim = 1, mode = "c"] alpha = np.zeros([n1]) cdef np.ndarray[double, ndim = 1, mode = "c"] beta = np.zeros([n2]) - + if not len(a): a=np.ones((n1,))/n1 if not len(b): b=np.ones((n2,))/n2 # calling the function - EMD_wrap(n1,n2,<double*> a.data,<double*> b.data,<double*> M.data,<double*> G.data, - <double*> alpha.data, <double*> beta.data, <double*> &cost, maxiter) - + cdef int resultSolver = 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 resultSolver != OPTIMAL: + if resultSolver == INFEASIBLE: + print("Problem infeasible. Try to inscrease numItermax.") + elif resultSolver == UNBOUNDED: + print("Problem unbounded") return cost, alpha, beta |