From 74ea83c0b621a96955835a71be2552d85c77db97 Mon Sep 17 00:00:00 2001
From: rozetko <rozetko@corpglory.com>
Date: Fri, 14 Sep 2018 18:59:53 +0300
Subject: [PATCH] Reduce amount of required labeled segments for learning #147
 (#153)

* rm labeled segments amount check && change query range algorithm

* review fix

* typo fix

* minor fix
---
 .../src/controllers/analytics_controller.ts   | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/server/src/controllers/analytics_controller.ts b/server/src/controllers/analytics_controller.ts
index 6a29fe8..64ff280 100644
--- a/server/src/controllers/analytics_controller.ts
+++ b/server/src/controllers/analytics_controller.ts
@@ -74,15 +74,16 @@ async function runTask(task: AnalyticsTask): Promise<TaskResult> {
  * @param segments labeled segments
  */
 function getQueryRangeForLearningBySegments(segments: Segment.Segment[]) {
-  if(segments.length < 2) {
-    throw new Error('Need at least 2 labeled segments');
+  if(segments.length === 0) {
+    throw new Error('Need at least 1 labeled segment');
   }
 
   let from = _.minBy(segments, s => s.from).from;
   let to = _.maxBy(segments, s => s.to).to;
-  let diff = to - from;
-  from -= Math.round(diff);
-  to = Date.now();
+  let now = Date.now();
+  let leftOffset = now - to;
+  from -= Math.round(leftOffset);
+  to = now;
 
   return { from, to };
 }
@@ -96,8 +97,8 @@ export async function runLearning(id: AnalyticUnit.AnalyticUnitId) {
     }
 
     let segments = await Segment.findMany(id, { labeled: true });
-    if(segments.length < 2) {
-      throw new Error('Need at least 2 labeled segments');
+    if(segments.length === 0) {
+      throw new Error('Need at least 1 labeled segment');
     }
 
     let segmentObjs = segments.map(s => s.toObject());
@@ -140,8 +141,8 @@ export async function runPredict(id: AnalyticUnit.AnalyticUnitId) {
     let pattern = unit.type;
 
     let segments = await Segment.findMany(id, { labeled: true });
-    if(segments.length < 2) {
-      throw new Error('Need at least 2 labeled segments');
+    if(segments.length === 0) {
+      throw new Error('Need at least 1 labeled segment');
     }
 
     let { from, to } = getQueryRangeForLearningBySegments(segments);