From 48968a8ad584cde278eabad268eed760d3d7d706 Mon Sep 17 00:00:00 2001
From: Jeremy Stein <j.stein@ucl.ac.uk>
Date: Mon, 2 Dec 2024 09:53:47 +0000
Subject: [PATCH] Make data more realistic by not enabling all streams for all
 patients.

---
 .../waveform_generator/Hl7Generator.java      | 25 ++++++++++++++-----
 1 file changed, 19 insertions(+), 6 deletions(-)

diff --git a/waveform-generator/src/main/java/uk/ac/ucl/rits/inform/datasources/waveform_generator/Hl7Generator.java b/waveform-generator/src/main/java/uk/ac/ucl/rits/inform/datasources/waveform_generator/Hl7Generator.java
index 4336566a3..155a3b432 100644
--- a/waveform-generator/src/main/java/uk/ac/ucl/rits/inform/datasources/waveform_generator/Hl7Generator.java
+++ b/waveform-generator/src/main/java/uk/ac/ucl/rits/inform/datasources/waveform_generator/Hl7Generator.java
@@ -295,17 +295,27 @@ public List<String> makeSyntheticWaveformMsgsAllPatients(
             Instant startTime, long numPatients, long numMillis) {
         List<String> waveformMsgs = new ArrayList<>();
         numPatients = Math.min(numPatients, possibleLocations.size());
+        List<SyntheticStream> syntheticStreams = List.of(
+                new SyntheticStream("52912", 50, 0.3, 5), // airway volume
+                new SyntheticStream("27", 300, 1.2, 10) // ECG
+        );
         for (int p = 0; p < numPatients; p++) {
             var location = possibleLocations.get(p);
-            String streamId1 = "52912"; // airway volume
-            String streamId2 = "27"; // ECG
             int sizeBefore = waveformMsgs.size();
             // each bed has a slightly different frequency
             double frequencyFactor =  0.95 + 0.1 * p / possibleLocations.size();
-            waveformMsgs.addAll(makeSyntheticWaveformMsgs(
-                    location, streamId1, 50, 0.3 * frequencyFactor, numMillis, startTime, 5));
-            waveformMsgs.addAll(makeSyntheticWaveformMsgs(
-                    location, streamId2, 300, 1.2 * frequencyFactor, numMillis, startTime, 10));
+            // don't turn on all streams for all patients to test more realistically
+            long streamsEnabledBitPattern = ~p; // p = 0 has all streams enabled, etc
+            for (int si = 0; si < syntheticStreams.size(); si++) {
+                boolean thisStreamEnabled = 0 != ((streamsEnabledBitPattern >> si) & 1);
+                if (!thisStreamEnabled) {
+                    continue;
+                }
+                SyntheticStream stream = syntheticStreams.get(si);
+                waveformMsgs.addAll(makeSyntheticWaveformMsgs(
+                        location, stream.streamId, stream.samplingRate,
+                        stream.baselineSignalFrequency * frequencyFactor, numMillis, startTime, stream.maxSamplesPerMessage));
+            }
             int sizeAfter = waveformMsgs.size();
             logger.debug("Patient {} (location {}), generated {} messages", p, location, sizeAfter - sizeBefore);
         }
@@ -313,6 +323,9 @@ public List<String> makeSyntheticWaveformMsgsAllPatients(
         return waveformMsgs;
     }
 
+    record SyntheticStream(String streamId, int samplingRate, double baselineSignalFrequency, int maxSamplesPerMessage) {
+    }
+
     private class GeneratorContext {
         private final Map<ImmutablePair<String, String>, GeneratorContextRecord> allContexts = new HashMap<>();