improved rvs implementations (#95)

HDembinski · Feb 9, 2024 · 89dc80f · 89dc80f
1 parent 3ac5b8e
commit 89dc80f
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Showing 5 changed files with 6 additions and 11 deletions.
diff --git a/src/numba_stats/expon.py b/src/numba_stats/expon.py
@@ -62,8 +62,7 @@ def _ppf(p, loc, scale):
 @_rvs_jit(2)
 def _rvs(loc, scale, size, random_state):
     _seed(random_state)
-    p = np.random.uniform(0, 1, size)
-    return _ppf(p, loc, scale)
+    return loc + np.random.exponential(scale, size)
 
 
 _generate_wrappers(globals())
diff --git a/src/numba_stats/laplace.py b/src/numba_stats/laplace.py
@@ -60,8 +60,7 @@ def _ppf(p, loc, scale):
 @_rvs_jit(2)
 def _rvs(loc, scale, size, random_state):
     _seed(random_state)
-    p = np.random.uniform(0, 1, size)
-    return _ppf(p, loc, scale)
+    return np.random.laplace(loc, scale, size)
 
 
 _generate_wrappers(globals())
diff --git a/src/numba_stats/lognorm.py b/src/numba_stats/lognorm.py
@@ -61,8 +61,7 @@ def _ppf(p, s, loc, scale):
 @_rvs_jit(3, cache=False)
 def _rvs(s, loc, scale, size, random_state):
     _seed(random_state)
-    p = np.random.uniform(0, 1, size)
-    return _ppf(p, s, loc, scale)
+    return loc + scale * np.random.lognormal(0, s, size)
 
 
 _generate_wrappers(globals())
diff --git a/src/numba_stats/t.py b/src/numba_stats/t.py
@@ -61,11 +61,10 @@ def _ppf(p, df, loc, scale):
     return scale * r + loc
 
 
-@_rvs_jit(3, cache=False)
+@_rvs_jit(3)
 def _rvs(df, loc, scale, size, random_state):
     _seed(random_state)
-    p = np.random.uniform(0, 1, size)
-    return _ppf(p, df, loc, scale)
+    return loc + scale * np.random.standard_t(df, size)
 
 
 _generate_wrappers(globals())
diff --git a/src/numba_stats/uniform.py b/src/numba_stats/uniform.py
@@ -55,8 +55,7 @@ def _ppf(p, a, w):
 @_rvs_jit(2)
 def _rvs(a, w, size, random_state):
     _seed(random_state)
-    p = np.random.uniform(0, 1, size)
-    return _ppf(p, a, w)
+    return np.random.uniform(a, a + w, size)
 
 
 _generate_wrappers(globals())