Graded relu (#860)

* GradedReluVec process and tests.

* changed test to use thresh not 0.

* removed duplicate docstring line.

* Bump tornado from 6.4 to 6.4.1 (#863)

Bumps [tornado](https://github.com/tornadoweb/tornado) from 6.4 to 6.4.1.
- [Changelog](https://github.com/tornadoweb/tornado/blob/master/docs/releases.rst)
- [Commits](tornadoweb/tornado@v6.4.0...v6.4.1)

---
updated-dependencies:
- dependency-name: tornado
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

* Fix: subthreshold dynamics equation of refractory lif (#842)

* Fix: subthreshold dynamics equation of refractory lif

* Fix: RefractoryLIF unit test to test the voltage dynamics

* Bump urllib3 from 2.2.1 to 2.2.2 (#865)

Bumps [urllib3](https://github.com/urllib3/urllib3) from 2.2.1 to 2.2.2.
- [Release notes](https://github.com/urllib3/urllib3/releases)
- [Changelog](https://github.com/urllib3/urllib3/blob/main/CHANGES.rst)
- [Commits](urllib3/urllib3@2.2.1...2.2.2)

---
updated-dependencies:
- dependency-name: urllib3
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: PhilippPlank <[email protected]>

---------

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: João Gil <[email protected]>
Co-authored-by: PhilippPlank <[email protected]>
Co-authored-by: Marcus G K Williams <[email protected]>

src/lava/proc/graded/models.py

@@ -11,7 +11,8 @@
 from lava.magma.core.decorator import implements, requires, tag
 from lava.magma.core.model.py.model import PyLoihiProcessModel
 
-from lava.proc.graded.process import GradedVec, NormVecDelay, InvSqrt
+from lava.proc.graded.process import (GradedVec, GradedReluVec,
+                                      NormVecDelay, InvSqrt)
 
 
 class AbstractGradedVecModel(PyLoihiProcessModel):
@@ -51,6 +52,43 @@ class PyGradedVecModelFixed(AbstractGradedVecModel):
     exp: np.ndarray = LavaPyType(np.ndarray, np.int32, precision=24)
 
 
+class AbstractGradedReluVecModel(PyLoihiProcessModel):
+    """Implementation of GradedReluVec"""
+
+    a_in = None
+    s_out = None
+    v = None
+    vth = None
+    exp = None
+
+    def run_spk(self) -> None:
+        """The run function that performs the actual computation during
+        execution orchestrated by a PyLoihiProcessModel using the
+        LoihiProtocol.
+        """
+        a_in_data = self.a_in.recv()
+        self.v += a_in_data
+
+        is_spike = self.v > self.vth
+        sp_out = self.v * is_spike
+
+        self.v[:] = 0
+
+        self.s_out.send(sp_out)
+
+
+@implements(proc=GradedReluVec, protocol=LoihiProtocol)
+@requires(CPU)
+@tag('fixed_pt')
+class PyGradedReluVecModelFixed(AbstractGradedReluVecModel):
+    """Fixed point implementation of GradedVec"""
+    a_in = LavaPyType(PyInPort.VEC_DENSE, np.int32, precision=24)
+    s_out = LavaPyType(PyOutPort.VEC_DENSE, np.int32, precision=24)
+    vth: np.ndarray = LavaPyType(np.ndarray, np.int32, precision=24)
+    v: np.ndarray = LavaPyType(np.ndarray, np.int32, precision=24)
+    exp: np.ndarray = LavaPyType(np.ndarray, np.int32, precision=24)
+
+
 @implements(proc=NormVecDelay, protocol=LoihiProtocol)
 @requires(CPU)
 @tag('fixed_pt')

src/lava/proc/graded/process.py

@@ -34,6 +34,45 @@ class GradedVec(AbstractProcess):
     Graded spike vector layer. Transmits accumulated input as
     graded spike with no dynamics.
 
+    v[t] = a_in
+    s_out = v[t] * (|v[t]| > vth)
+
+    Parameters
+    ----------
+    shape: tuple(int)
+        number and topology of neurons
+    vth: int
+        threshold for spiking
+    exp: int
+        fixed point base
+    """
+
+    def __init__(
+            self,
+            shape: ty.Tuple[int, ...],
+            vth: ty.Optional[int] = 1,
+            exp: ty.Optional[int] = 0) -> None:
+
+        super().__init__(shape=shape)
+
+        self.a_in = InPort(shape=shape)
+        self.s_out = OutPort(shape=shape)
+
+        self.v = Var(shape=shape, init=0)
+        self.vth = Var(shape=(1,), init=vth)
+        self.exp = Var(shape=(1,), init=exp)
+
+    @property
+    def shape(self) -> ty.Tuple[int, ...]:
+        """Return shape of the Process."""
+        return self.proc_params['shape']
+
+
+class GradedReluVec(AbstractProcess):
+    """GradedReluVec
+    Graded spike vector layer. Transmits accumulated input as
+    graded spike with no dynamics.
+
     v[t] = a_in
     s_out = v[t] * (v[t] > vth)
 

tests/lava/proc/graded/test_graded.py

@@ -6,7 +6,8 @@
 import numpy as np
 from scipy.sparse import csr_matrix
 
-from lava.proc.graded.process import GradedVec, NormVecDelay, InvSqrt
+from lava.proc.graded.process import (GradedVec, GradedReluVec,
+                                      NormVecDelay, InvSqrt)
 from lava.proc.graded.models import inv_sqrt
 from lava.proc.dense.process import Dense
 from lava.proc.sparse.process import Sparse
@@ -59,7 +60,7 @@ def test_gradedvec_dot_dense(self):
         self.assertTrue(np.all(out_data[:, (3, 7)] == expected_out[:, (2, 6)]))
 
     def test_gradedvec_dot_sparse(self):
-        """Tests that GradedVec and Dense computes dot product."""
+        """Tests that GradedVec and Sparse computes dot product"""
         num_steps = 10
         v_thresh = 1
 
@@ -99,6 +100,91 @@ def test_gradedvec_dot_sparse(self):
         self.assertTrue(np.all(out_data[:, (3, 7)] == expected_out[:, (2, 6)]))
 
 
+class TestGradedReluVecProc(unittest.TestCase):
+    """Tests for GradedReluVec"""
+
+    def test_gradedreluvec_dot_dense(self):
+        """Tests that GradedReluVec and Dense computes dot product"""
+        num_steps = 10
+        v_thresh = 1
+
+        weights1 = np.zeros((10, 1))
+        weights1[:, 0] = (np.arange(10) - 5) * 0.2
+
+        inp_data = np.zeros((weights1.shape[1], num_steps))
+        inp_data[:, 2] = 1000
+        inp_data[:, 6] = 20000
+
+        weight_exp = 7
+        weights1 *= 2**weight_exp
+        weights1 = weights1.astype('int')
+
+        dense1 = Dense(weights=weights1, num_message_bits=24,
+                       weight_exp=-weight_exp)
+        vec1 = GradedReluVec(shape=(weights1.shape[0],),
+                             vth=v_thresh)
+
+        generator = io.source.RingBuffer(data=inp_data)
+        logger = io.sink.RingBuffer(shape=(weights1.shape[0],),
+                                    buffer=num_steps)
+
+        generator.s_out.connect(dense1.s_in)
+        dense1.a_out.connect(vec1.a_in)
+        vec1.s_out.connect(logger.a_in)
+
+        vec1.run(condition=RunSteps(num_steps=num_steps),
+                 run_cfg=Loihi2SimCfg(select_tag='fixed_pt'))
+        out_data = logger.data.get().astype('int')
+        vec1.stop()
+
+        ww = np.floor(weights1 / 2) * 2
+        expected_out = np.floor((ww @ inp_data) / 2**weight_exp)
+        expected_out *= expected_out > v_thresh
+
+        self.assertTrue(np.all(out_data[:, (3, 7)] == expected_out[:, (2, 6)]))
+
+    def test_gradedreluvec_dot_sparse(self):
+        """Tests that GradedReluVec and Sparse computes dot product"""
+        num_steps = 10
+        v_thresh = 1
+
+        weights1 = np.zeros((10, 1))
+        weights1[:, 0] = (np.arange(10) - 5) * 0.2
+
+        inp_data = np.zeros((weights1.shape[1], num_steps))
+        inp_data[:, 2] = 1000
+        inp_data[:, 6] = 20000
+
+        weight_exp = 7
+        weights1 *= 2**weight_exp
+        weights1 = weights1.astype('int')
+
+        sparse1 = Sparse(weights=csr_matrix(weights1),
+                         num_message_bits=24,
+                         weight_exp=-weight_exp)
+        vec1 = GradedReluVec(shape=(weights1.shape[0],),
+                             vth=v_thresh)
+
+        generator = io.source.RingBuffer(data=inp_data)
+        logger = io.sink.RingBuffer(shape=(weights1.shape[0],),
+                                    buffer=num_steps)
+
+        generator.s_out.connect(sparse1.s_in)
+        sparse1.a_out.connect(vec1.a_in)
+        vec1.s_out.connect(logger.a_in)
+
+        vec1.run(condition=RunSteps(num_steps=num_steps),
+                 run_cfg=Loihi2SimCfg(select_tag='fixed_pt'))
+        out_data = logger.data.get().astype('int')
+        vec1.stop()
+
+        ww = np.floor(weights1 / 2) * 2
+        expected_out = np.floor((ww @ inp_data) / 2**weight_exp)
+        expected_out *= expected_out > v_thresh
+
+        self.assertTrue(np.all(out_data[:, (3, 7)] == expected_out[:, (2, 6)]))
+
+
 class TestInvSqrtProc(unittest.TestCase):
     """Tests for inverse square process."""