diff --git a/sphereproj/copy.pxd b/sphereproj/copy.pxd
new file mode 100644
index 0000000..182bbba
--- /dev/null
+++ b/sphereproj/copy.pxd
@@ -0,0 +1,22 @@
+cimport cython
+cimport numpy as npx
+
+ctypedef fused sum_type:
+    cython.int
+    cython.float
+    npx.uint64_t
+    npx.uint32_t
+
+@cython.boundscheck(False)
+cdef inline sum_type _mysum(sum_type[:] jobs) nogil:
+  cdef sum_type s
+  cdef npx.uint64_t N
+  cdef int i
+
+  s = 0
+  N = jobs.shape[0]
+  for i in xrange(N):
+    s += jobs[i]
+  return s
+
+