@esmj/monitor - npm Package Compare versions

Comparing version 0.3.0 to 0.4.0

dist/index.js

@@ -329,5 +329,22 @@ 'use strict';
 
-    return this.#calculate(array, number);
+    return this.#calculatePercentile(array, number);
   }
 
+  trend(key, limit) {
+    let array = this.#getValues(key);
+
+    array = array.slice(
+      !limit || limit > array.length ? 0 : array.length - limit,
+      array.length
+    );
+
+    const { slope, yIntercept } = this.#getLinearRegression(array);
+
+    return {
+      slope,
+      yIntercept,
+      predict: (x = array.length + 1) => slope * x + yIntercept,
+    };
+  }
+
   #getValues(key) {
@@ -343,3 +360,35 @@ const keys = key?.split('.') ?? [];
 
-  #calculate(array, number) {
+  #getLinearRegression(array) {
+    const { sumY, sumX, sumX2, sumXY } = array.reduce(
+      (result, value, index) => {
+        const x = value?.x ?? index + 1;
+        const y = value?.y ?? value;
+        result.sumX += x;
+        result.sumY += y;
+        result.sumX2 += x * x;
+        result.sumXY += x * y;
+
+        return result;
+      },
+      {
+        sumY: 0,
+        sumX: 0,
+        sumX2: 0,
+        sumXY: 0,
+      }
+    );
+
+    const divisor = array.length * sumX2 - sumX * sumX;
+
+    if (divisor === 0) {
+      return { slope: 0, yIntercept: 0 };
+    }
+
+    const yIntercept = (sumY * sumX2 - sumX * sumXY) / divisor;
+    const slope = (array.length * sumXY - sumX * sumY) / divisor;
+
+    return { slope, yIntercept };
+  }
+
+  #calculatePercentile(array, number) {
     if (!array.length) {
@@ -346,0 +395,0 @@ return undefined;

package.json

 {
   "name": "@esmj/monitor",
-  "version": "0.3.0",
+  "version": "0.4.0",
   "description": "Node.js performance measurement metrics (cpu, memory, event loop, gc)",
@@ -5,0 +5,0 @@ "keywords": [

README.md

@@ -114,3 +114,3 @@ # Monitor
 #### add(metric)
-Monitoring start measure node metric.
+Monitoring add measure new metric.
 
@@ -141,6 +141,6 @@ ##### metric
 
-FIFO size of array for calculating percentile.
+FIFO size of array for calculating percentile and linear regressions.
 
-#### percentile(key, value)
-Monitoring start measure node metric.
+#### percentile(key, number)
+Returns defined percentile for measured metric
 
@@ -153,6 +153,21 @@ ##### key
 
-##### value
+##### number
 
 Type: `Number`
 
-Percentile number for FIFO array
+Percentile number for FIFO array
+
+#### trend(key, limit)
+Returns linear regression variables `slope`, `yIntercept` and `predict` function for measured metric.
+
+##### key
+
+Type: `String`
+
+Path in measured metric structure.
+
+##### limit
+
+Type: `Number`
+
+Defined how much records use for calculating linear regression. Default is use all records from FIFO array. 

No alert changes

Improved metrics

Total package byte prevSize

37335

increased by11.15%

Lines of code

1099

increased by11.91%

Number of lines in readme file

170

increased by9.68%

No dependency changes