Implement multiplicative constant to apply to a Faust at initialization time.

The constant is named alpha, not lambda like in Matlab wrapper, because lambda is a keyword in Python (lambda functions).

wrapper/python/FaustPy.py

@@ -54,7 +54,7 @@ class Faust:
     matrix.
     """
 
-    def  __init__(F, list_factors=None, filepath=None, core_obj=None):
+    def  __init__(F, list_factors=None, alpha=1.0, filepath=None, core_obj=None):
         """ Creates a Faust from a list of factors or alternatively from a file.
 
             Another easy way to create a Faust is to call the static method Faust.randFaust().
@@ -62,6 +62,9 @@ class Faust:
         Args:
             list_factors: list/tuple of numpy matrices (either
             scipy.sparse.csr.csr_matrix or numpy.ndarray).
+            alpha: multiplicative scalar applied to the factor product before
+            to set the Faust with. Note that the constant is ignored if
+            list_factors argument isn't used.
             filepath: the file in Matlab format (.mat) from which a Faust will
             be created (the file must have been saved before with
             Faust.save()).
@@ -81,7 +84,7 @@ class Faust:
                     contents = loadmat(filepath)
                     list_factors = contents['faust_factors'][0]
             if(list_factors is not None):
-                F.m_faust = FaustCorePy.FaustCore(list_factors);
+                F.m_faust = FaustCorePy.FaustCore(list_factors, alpha);
             #else:
                 #TODO: manage empty Faust
 

wrapper/python/src/FaustCorePy.pyx

@@ -50,6 +50,7 @@ from libcpp cimport bool
 from libcpp cimport complex
 from cpython.mem cimport PyMem_Malloc, PyMem_Realloc, PyMem_Free
 from scipy import sparse
+from re import match
 
 cdef class FaustCore:
 
@@ -60,7 +61,7 @@ cdef class FaustCore:
     cdef bool _isReal
     #### CONSTRUCTOR ####
     #def __cinit__(self,np.ndarray[double, mode="fortran", ndim=2] mat):
-    def  __cinit__(self,list_factors=None, core=False):
+    def  __cinit__(self,list_factors=None, alpha=1.0, core=False):
         cdef double [:,:] data
         cdef double [:] data1d #only for csr mat factor
         cdef int [:] indices # only for csr mat
@@ -70,6 +71,9 @@ cdef class FaustCore:
         cdef unsigned int nbrow
         cdef unsigned int nbcol
         if(list_factors is not None):
+            if(match('.*int', repr(list_factors[0].dtype))):
+               list_factors[0] = list_factors[0].astype(np.float)
+            list_factors[0] *= alpha
             self._isReal = True
             for i,factor in enumerate(list_factors):
                 # Faust uses row-major order for sparse matrices