added first attempt at quantump integrator

Author: scarlehoff

examples/quantum_mc.py

@@ -0,0 +1,35 @@
+"""
+Run integration with qibo as the backend
+"""
+
+from vegasflow.quantum import quantum_wrapper
+from vegasflow import float_me
+import time
+import numpy as np
+import tensorflow as tf
+
+
+# MC integration setup
+dim = 2
+ncalls = int(1e2)
+n_iter = 5
+
+
+def symgauss(xarr):
+    """symgauss test function"""
+    n_dim = xarr.shape[-1]
+    a = float_me(0.1)
+    n100 = float_me(100 * n_dim)
+    pref = tf.pow(1.0 / a / np.sqrt(np.pi), n_dim)
+    coef = tf.reduce_sum(tf.range(n100 + 1))
+    coef += tf.reduce_sum(tf.square((xarr - 1.0 / 2.0) / a), axis=1)
+    coef -= (n100 + 1) * n100 / 2.0
+    return pref * tf.exp(-coef)
+
+
+if __name__ == "__main__":
+    """Testing several different integrations"""
+    print(f"VEGAS MC, ncalls={ncalls}:")
+    start = time.time()
+    result = quantum_wrapper(symgauss, dim, n_iter, ncalls)
+    end = time.time()

pyproject.toml

@@ -24,6 +24,9 @@ dependencies = [
 ]
 
 [project.optional-dependencies] 
+quantum = [
+  "qibolab[qrng] @ git+https://github.com/qiboteam/qibolab@qrng"
+]
 docs = [
 'sphinx_rtd_theme',
 'recommonmark',
@@ -55,4 +58,3 @@ profile = "black" # https://black.readthedocs.io/en/stable/guides/using_black_wi
 skip_gitignore = true
 known_first_party = ["bgtrees"]
 force_sort_within_sections = true
-

src/vegasflow/quantum.py

@@ -0,0 +1,70 @@
+"""
+A Monte Carlo integrator built upon Qibo for quantum integration
+"""
+
+from .monte_carlo import wrapper, sampler
+from .plain import PlainFlow  # start building upon a naive idiotic integrator
+from .configflow import run_eager, DTYPE
+import tensorflow as tf
+
+
+class QuantumIntegrator(PlainFlow):
+    """
+    Simple Monte Carlo integrator.
+    """
+
+    _CAN_RUN_VECTORIAL = False
+
+    def __init__(self, *args, **kwargs):
+        # This integrator can only run for now in eager mode and needs qibolab to be installed
+        run_eager(True)
+
+        try:
+            from qibolab.instruments.qrng import QRNG
+            from serial.serialutil import SerialException
+        except ModuleNotFoundError as e:
+            raise ModuleNotFoundError("You can do pip install vegasflow[quantum]") from e
+
+        try:
+            qrng = QRNG(address="/dev/ttyACM0")
+            qrng.connect()
+        except SerialException as e:
+            raise SerialException("No quantum device found") from e
+
+        self._quantum_sampler = qrng
+        super().__init__(*args, **kwargs)
+
+    def run_integration(self, *args, **kwargs):
+        ret = super().run_integration(*args, **kwargs)
+        self._quantum_sampler.disconnect()
+        return ret
+
+    def _generate_random_array(self, n_events, *args):
+        """
+        Returns
+            -------
+                `rnds`: array of (n_events, n_dim) random points
+                `idx` : index associated to each random point
+                `wgt` : wgt associated to the random point
+        """
+        quantum_rnds_raw = self._quantum_sampler.random((n_events, self.n_dim))
+        rnds_raw = tf.cast(quantum_rnds_raw, dtype=DTYPE)
+
+        rnds, wgts_raw, *extra = self._digest_random_generation(rnds_raw, *args)
+
+        wgts = wgts_raw * self.xjac
+        if self._xdelta is not None:
+            # Now apply integration limits
+            rnds = self._xmin + rnds * self._xdelta
+            wgts *= self._xdeltajac
+        return rnds, wgts, *extra
+
+
+def quantum_wrapper(*args, **kwargs):
+    """Wrapper around QuantumIntegrator"""
+    return wrapper(QuantumIntegrator, *args, **kwargs)
+
+
+def quantum_sampler(*args, **kwargs):
+    """Wrapper sampler around QuantumIntegrator"""
+    return sampler(QuantumIntegrator, *args, **kwargs)