update infectionswithfeedback process

docs/source/tutorials/extending_pyrenew.qmd

@@ -168,7 +168,7 @@ InfFeedbackSample = namedtuple(
 )
 ```
 
-The next step is to create the actual class. The bulk of its implementation lies in the function `pyrenew.latent.compute_infections_from_rt_with_feedback()`. We will also use the `pyrenew.arrayutils.pad_x_to_match_y()` function to ensure the passed vectors match their lengths. The following code-chunk shows most of the implementation of the `InfectionsWithFeedback` class:
+The next step is to create the actual class. The bulk of its implementation lies in the function `pyrenew.latent.compute_infections_from_rt_with_feedback()`. We will also use the `pyrenew.arrayutils.pad_edges_to_match()` function to ensure the passed vectors match their lengths. The following code-chunk shows most of the implementation of the `InfectionsWithFeedback` class:
 
 ```{python}
 # | label: new-model-def
@@ -224,11 +224,10 @@ class InfFeedback(RandomVariable):
 
         inf_feedback_strength = jnp.atleast_1d(inf_feedback_strength)
 
-        inf_feedback_strength = au.pad_x_to_match_y(
+        inf_feedback_strength = au.pad_edges_to_match(
             x=inf_feedback_strength,
             y=Rt,
-            fill_value=inf_feedback_strength[0],
-        )
+        )[0]
 
         # Sampling inf feedback and adjusting the shape
         inf_feedback_pmf = self.infection_feedback_pmf(**kwargs)

pyrenew/arrayutils.py

@@ -8,24 +8,25 @@
 from jax.typing import ArrayLike
 
 
-def pad_to_match(
+def pad_edges_to_match(
     x: ArrayLike,
     y: ArrayLike,
-    fill_value: float = 0.0,
+    axis: int = 0,
     pad_direction: str = "end",
     fix_y: bool = False,
 ) -> tuple[ArrayLike, ArrayLike]:
     """
-    Pad the shorter array at the start or end to match the length of the longer array.
+    Pad the shorter array at the start or end using the
+    edge values to match the length of the longer array.
 
     Parameters
     ----------
     x : ArrayLike
         First array.
     y : ArrayLike
         Second array.
-    fill_value : float, optional
-        Value to use for padding, by default 0.0.
+    axis : int, optional
+        Axis along which to add padding, by default 0
     pad_direction : str, optional
         Direction to pad the shorter array, either "start" or "end", by default "end".
     fix_y : bool, optional
@@ -38,64 +39,35 @@ def pad_to_match(
     """
     x = jnp.atleast_1d(x)
     y = jnp.atleast_1d(y)
-    x_len = x.size
-    y_len = y.size
+    x_len = x.shape[axis]
+    y_len = y.shape[axis]
     pad_size = abs(x_len - y_len)
+    pad_width = [(0, 0)] * x.ndim
 
-    pad_width = {"start": (pad_size, 0), "end": (0, pad_size)}.get(
-        pad_direction, None
-    )
-
-    if pad_width is None:
+    if pad_direction not in ["start", "end"]:
         raise ValueError(
             "pad_direction must be either 'start' or 'end'."
             f" Got {pad_direction}."
         )
 
+    pad_width[axis] = {"start": (pad_size, 0), "end": (0, pad_size)}.get(
+        pad_direction, None
+    )
+
     if x_len > y_len:
         if fix_y:
             raise ValueError(
                 "Cannot fix y when x is longer than y."
                 f" x_len: {x_len}, y_len: {y_len}."
             )
-        y = jnp.pad(y, pad_width, constant_values=fill_value)
+        y = jnp.pad(y, pad_width, mode="edge")
 
     elif y_len > x_len:
-        x = jnp.pad(x, pad_width, constant_values=fill_value)
+        x = jnp.pad(x, pad_width, mode="edge")
 
     return x, y
 
 
-def pad_x_to_match_y(
-    x: ArrayLike,
-    y: ArrayLike,
-    fill_value: float = 0.0,
-    pad_direction: str = "end",
-) -> ArrayLike:
-    """
-    Pad the `x` array at the start or end to match the length of the `y` array.
-
-    Parameters
-    ----------
-    x : ArrayLike
-        First array.
-    y : ArrayLike
-        Second array.
-    fill_value : float, optional
-        Value to use for padding, by default 0.0.
-    pad_direction : str, optional
-        Direction to pad the shorter array, either "start" or "end", by default "end".
-
-    Returns
-    -------
-    Array
-        Padded array.
-    """
-    return pad_to_match(
-        x, y, fill_value=fill_value, pad_direction=pad_direction, fix_y=True
-    )[0]
-
-
 class PeriodicProcessSample(NamedTuple):
     """
     A container for holding the output from `process.PeriodicProcess()`.

pyrenew/convolve.py

@@ -80,7 +80,9 @@ def _new_scanner(
         new_val = transform(
             multiplier * jnp.dot(array_to_convolve, history_subset)
         )
-        latest = jnp.hstack([history_subset[1:], new_val])
+        latest = jnp.concatenate(
+            [history_subset[1:], jnp.expand_dims(new_val, axis=0)]
+        )
         return latest, new_val
 
     return _new_scanner
@@ -160,7 +162,9 @@ def _new_scanner(
         m1, m2 = multipliers
         m_net1 = t1(m1 * jnp.dot(arr1, history_subset))
         new_val = t2(m2 * m_net1 * jnp.dot(arr2, history_subset))
-        latest = jnp.hstack([history_subset[1:], new_val])
+        latest = jnp.concatenate(
+            [history_subset[1:], jnp.expand_dims(new_val, axis=0)]
+        )
         return latest, (new_val, m_net1)
 
     return _new_scanner

pyrenew/latent/infections.py

@@ -80,14 +80,21 @@ def sample(
         InfectionsSample
             Named tuple with "infections".
         """
-        if I0.size < gen_int.size:
+        if I0.shape[0] < gen_int.size:
             raise ValueError(
                 "Initial infections vector must be at least as long as "
                 "the generation interval. "
-                f"Initial infections vector length: {I0.size}, "
+                f"Initial infections vector length: {I0.shape[0]}, "
                 f"generation interval length: {gen_int.size}."
             )
 
+        if I0.ndim != Rt.ndim:
+            raise ValueError(
+                "Initial infections and Rt must have the same dimensions. "
+                f"Got initial infections of shape {I0.shape} "
+                f"and Rt of shape {Rt.shape}."
+            )
+
         gen_int_rev = jnp.flip(gen_int)
         recent_I0 = I0[-gen_int_rev.size :]
 

pyrenew/latent/infectionswithfeedback.py

@@ -143,11 +143,18 @@ def sample(
         InfectionsWithFeedback
             Named tuple with "infections".
         """
-        if I0.size < gen_int.size:
+        if I0.shape[0] < gen_int.size:
             raise ValueError(
                 "Initial infections must be at least as long as the "
-                f"generation interval. Got {I0.size} initial infections "
-                f"and {gen_int.size} generation interval."
+                f"generation interval. Got initial infections length {I0.shape[0]}"
+                f"and generation interval length {gen_int.size}."
+            )
+
+        if I0.ndim != Rt.ndim:
+            raise ValueError(
+                "Initial infections and Rt must have the same dimensions. "
+                f"Got initial infections of shape {I0.shape} "
+                f"and Rt of shape {Rt.shape}."
             )
 
         gen_int_rev = jnp.flip(gen_int)
@@ -160,19 +167,23 @@ def sample(
                 **kwargs,
             )
         )
+
+        if inf_feedback_strength.ndim < Rt.ndim:
+            inf_feedback_strength = jnp.expand_dims(inf_feedback_strength, 0)
+
         # Making sure inf_feedback_strength spans the Rt length
-        if inf_feedback_strength.size == 1:
-            inf_feedback_strength = au.pad_x_to_match_y(
+        if inf_feedback_strength.shape[0] == 1:
+            inf_feedback_strength = au.pad_edges_to_match(
                 x=inf_feedback_strength,
                 y=Rt,
-                fill_value=inf_feedback_strength[0],
-            )
-        elif inf_feedback_strength.size != Rt.size:
+                axis=0,
+            )[0]
+        elif inf_feedback_strength.shape != Rt.shape:
             raise ValueError(
-                "Infection feedback strength must be of size 1 "
-                "or the same size as the reproduction number array. "
-                f"Got {inf_feedback_strength.size} "
-                f"and {Rt.size} respectively."
+                "Infection feedback strength must be of length 1 "
+                "or the same length as the reproduction number array. "
+                f"Got {inf_feedback_strength.shape} "
+                f"and {Rt.shape} respectively."
             )
 
         # Sampling inf feedback pmf

test/test_arrayutils.py

@@ -8,53 +8,67 @@
 import pyrenew.arrayutils as au
 
 
-def test_arrayutils_pad_to_match():
+def test_pad_edges_to_match():
     """
-    Verifies extension when required and error when `fix_y` is True.
+    Test function to verify padding along the edges for 1D and 2D arrays
     """
 
+    # test when y gets padded
     x = jnp.array([1, 2, 3])
     y = jnp.array([1, 2])
 
-    x_pad, y_pad = au.pad_to_match(x, y)
-
+    x_pad, y_pad = au.pad_edges_to_match(x, y)
     assert x_pad.size == y_pad.size
-    assert x_pad.size == 3
+    assert y_pad[-1] == y[-1]
 
+    # test when x gets padded
     x = jnp.array([1, 2])
     y = jnp.array([1, 2, 3])
 
-    x_pad, y_pad = au.pad_to_match(x, y)
-
+    x_pad, y_pad = au.pad_edges_to_match(x, y)
     assert x_pad.size == y_pad.size
-    assert x_pad.size == 3
+    assert x_pad[-1] == x[-1]
 
+    # test when no padding required
     x = jnp.array([1, 2, 3])
-    y = jnp.array([1, 2])
+    y = jnp.array([4, 5, 6])
+    x_pad, y_pad = au.pad_edges_to_match(x, y)
 
-    # Verify that the function raises an error when `fix_y` is True
-    with pytest.raises(ValueError):
-        x_pad, y_pad = au.pad_to_match(x, y, fix_y=True)
+    assert jnp.array_equal(x_pad, x)
+    assert jnp.array_equal(y_pad, y)
 
     # Verify function works with both padding directions
-    x_pad, y_pad = au.pad_to_match(x, y, pad_direction="start")
+    x = jnp.array([1, 2, 3])
+    y = jnp.array([1, 2])
+
+    x_pad, y_pad = au.pad_edges_to_match(x, y, pad_direction="start")
 
     assert x_pad.size == y_pad.size
-    assert x_pad.size == 3
+    assert y_pad[0] == y[0]
+
+    # Verify that the function raises an error when `fix_y` is True
+    with pytest.raises(
+        ValueError, match="Cannot fix y when x is longer than y"
+    ):
+        x_pad, y_pad = au.pad_edges_to_match(x, y, fix_y=True)
 
     # Verify function raises an error when pad_direction is not "start" or "end"
     with pytest.raises(ValueError):
-        x_pad, y_pad = au.pad_to_match(x, y, pad_direction="middle")
+        x_pad, y_pad = au.pad_edges_to_match(x, y, pad_direction="middle")
 
+    # test padding for 2D arrays
+    x = jnp.array([[1, 2], [3, 4]])
+    y = jnp.array([[5, 6]])
 
-def test_arrayutils_pad_x_to_match_y():
-    """
-    Verifies extension when required
-    """
-
-    x = jnp.array([1, 2])
-    y = jnp.array([1, 2, 3])
+    # Padding along axis 0
+    axis = 0
+    x_pad, y_pad = au.pad_edges_to_match(x, y, axis=axis, pad_direction="end")
 
-    x_pad = au.pad_x_to_match_y(x, y)
+    assert jnp.array_equal(x_pad.shape[axis], y_pad.shape[axis])
+    assert jnp.array_equal(y_pad[-1], y[-1])
 
-    assert x_pad.size == 3
+    # padding along axis 1
+    axis = 1
+    x_pad, y_pad = au.pad_edges_to_match(x, y, axis=axis, pad_direction="end")
+    assert jnp.array_equal(x_pad.shape[axis], y_pad.shape[axis])
+    assert jnp.array_equal(y[:, -1], y_pad[:, -1])