Add support for float data type to numpy.random.randn call

randn_dtype.patch

diff --git a/mtrand/mtrand.pyx b/mtrand/mtrand.pyx
index 65c1954..79d0d70 100755
--- a/mtrand/mtrand.pyx
+++ b/mtrand/mtrand.pyx
@@ -71,6 +71,7 @@ cdef extern from "randomkit.h":
     rk_error rk_altfill(void *buffer, size_t size, int strong,
             rk_state *state) nogil
     double rk_gauss(rk_state *state) nogil
+    float rk_gauss_32bit(rk_state *state) nogil
     void rk_random_uint64(npy_uint64 off, npy_uint64 rng, npy_intp cnt,
                           npy_uint64 *out, rk_state *state) nogil
     void rk_random_uint32(npy_uint32 off, npy_uint32 rng, npy_intp cnt,
@@ -124,6 +125,7 @@ cdef extern from "distributions.h":
     long rk_logseries(rk_state *state, double p) nogil
 
 ctypedef double (* rk_cont0)(rk_state *state) nogil
+ctypedef float (* rk_cont0_32bit)(rk_state *state) nogil
 ctypedef double (* rk_cont1)(rk_state *state, double a) nogil
 ctypedef double (* rk_cont2)(rk_state *state, double a, double b) nogil
 ctypedef double (* rk_cont3)(rk_state *state, double a, double b, double c) nogil
@@ -172,6 +174,26 @@ cdef object cont0_array(rk_state *state, rk_cont0 func, object size,
                 array_data[i] = func(state)
         return array
 
+cdef object cont0_array_32bit(rk_state *state, rk_cont0_32bit func, object size,
+                               object lock):
+    cdef float *array_data
+    cdef ndarray array "arrayObject"
+    cdef npy_intp length
+    cdef npy_intp i
+    cdef float rv
+    if size is None:
+        with lock, nogil:
+            rv = func(state)
+        return rv
+    else:
+        array = <ndarray>np.empty(size, np.float32)
+        length = PyArray_SIZE(array)
+        array_data = <float *>PyArray_DATA(array)
+        with lock, nogil:
+            for i from 0 <= i < length:
+                array_data[i] = func(state)
+        return array
+
 
 cdef object cont1_array_sc(rk_state *state, rk_cont1 func, object size, double a,
                            object lock):
@@ -1500,7 +1522,7 @@ cdef class RandomState:
 
 
     # Complicated, continuous distributions:
-    def standard_normal(self, size=None):
+    def standard_normal(self, size=None, dtype=np.double):
         """
         standard_normal(size=None)
 
@@ -1531,7 +1553,10 @@ cdef class RandomState:
         (3, 4, 2)
 
         """
-        return cont0_array(self.internal_state, rk_gauss, size, self.lock)
+        if dtype==np.double:
+            return cont0_array(self.internal_state, rk_gauss, size, self.lock)
+        else:    
+            return cont0_array_32bit(self.internal_state, rk_gauss_32bit, size, self.lock)
 
     def normal(self, loc=0.0, scale=1.0, size=None):
         """
diff --git a/mtrand/randomkit.c b/mtrand/randomkit.c
index 3a95efe..fcc20c9 100755
--- a/mtrand/randomkit.c
+++ b/mtrand/randomkit.c
@@ -622,3 +622,9 @@ rk_gauss(rk_state *state)
         return f*x2;
     }
 }
+
+float
+rk_gauss_32bit(rk_state *state)
+{
+  return (float)rk_gauss(state);
+}
diff --git a/mtrand/randomkit.h b/mtrand/randomkit.h
index fcdd606..05d2f5f 100755
--- a/mtrand/randomkit.h
+++ b/mtrand/randomkit.h
@@ -218,6 +218,7 @@ extern rk_error rk_altfill(void *buffer, size_t size, int strong,
  * return a random gaussian deviate with variance unity and zero mean.
  */
 extern double rk_gauss(rk_state *state);
+extern float rk_gauss_32bit(rk_state *state);
 
 #ifdef __cplusplus
 }