everything is technically working

c/interaction/interaction.c

@@ -13,7 +13,6 @@ interaction_force_function
 	int i;
 	for(i = 0; i < 7; i++)
 	{
-		printf("%x\n", coefficients);
 		result += coefficients[i] * powf(r, i);
 	}
 	result *= coefficients[7] * expf(coefficients[8] * (r - coefficients[9]));
@@ -28,7 +27,7 @@ interaction_ufunc_force
 	( char ** args
 	, npy_intp * dimensions
 	, npy_intp * steps
-	, void ** data)
+	, void * data)
 {
 	char * in = args[0]
 		, * out = args[1];
@@ -38,9 +37,7 @@ interaction_ufunc_force
 
 	npy_intp i;
 
-	printf("DATA IS: %x\n", data);
-	printf("DATA[0] IS: %x\n", data[0]);
-	float * coefficients = (float *) data[0];
+	float * coefficients = (float *) data;
 
 	for(i = 0; i < n; i++)
 	{
@@ -139,6 +136,7 @@ typedef struct
 	PyObject_HEAD
 	float coefficients[19];
 	PyObject * ufunc;
+	void *data[1];
 } interaction_UFuncWrapper;
 
 static int
@@ -189,29 +187,30 @@ interaction_UFuncWrapper_init
 			return -1;
 		}
 	}
+	self->data[0] = (void *)self->coefficients;
 
 	switch(type)
 	{
 		case 0:
 		{
 			self->ufunc = PyUFunc_FromFuncAndData(
-				force_funcs
-				, (void **) &(self->coefficients)
-				, force_types
-				, 1
-				, 1
-				, 1
-				, PyUFunc_None
-				, "force_function"
-				, "computes the scalar force between two particles with given coefficients"
-				, 0);
+				force_funcs // func
+				, self->data // data
+				, force_types //types
+				, 1 // ntypes
+				, 1 // nin
+				, 1 // nout
+				, PyUFunc_None // identity
+				, "force_function" // name
+				, "computes the scalar force between two particles with given coefficients" // doc
+				, 0); // unused
 			break;
 		}
 		case 1:
 		{
 			self->ufunc = PyUFunc_FromFuncAndData(
 				interaction_funcs
-				, (void **) &(self->coefficients)
+				, self->data
 				, interaction_types
 				, 1
 				, 4
@@ -229,8 +228,6 @@ interaction_UFuncWrapper_init
 		}
 	}
 	Py_INCREF(self->ufunc);
-	printf("PASSED = %x\n", &(self->coefficients));
-	printf("PASSED[0] = %x\n", self->coefficients);
 	return 0;
 }
 

c/interaction/interaction.h

@@ -37,6 +37,6 @@ interaction_ufunc_force
 	( char ** args
 	, npy_intp * dimensions
 	, npy_intp * steps
-	, void ** data);
+	, void * data);
 
 #endif