From 2589e1a49fb9e8486e03334c6cd49aedf6b5547a Mon Sep 17 00:00:00 2001
From: Petar Petrov <MindFreeze@users.noreply.github.com>
Date: Mon, 9 Jun 2025 14:45:23 +0300
Subject: [PATCH] Handle tiny values in a log chart (#25727)

---
 src/components/chart/state-history-chart-line.ts | 14 ++++++++++----
 src/components/chart/statistics-chart.ts         | 14 ++++++++++----
 2 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/src/components/chart/state-history-chart-line.ts b/src/components/chart/state-history-chart-line.ts
index 53cc3b926b..f8f7689539 100644
--- a/src/components/chart/state-history-chart-line.ts
+++ b/src/components/chart/state-history-chart-line.ts
@@ -229,14 +229,20 @@ export class StateHistoryChartLine extends LitElement {
           minYAxis = ({ min }) => Math.min(min, this.minYAxis!);
         }
       } else if (this.logarithmicScale) {
-        minYAxis = ({ min }) => Math.floor(min > 0 ? min * 0.95 : min * 1.05);
+        minYAxis = ({ min }) => {
+          const value = min > 0 ? min * 0.95 : min * 1.05;
+          return Math.abs(value) < 1 ? value : Math.floor(value);
+        };
       }
       if (typeof maxYAxis === "number") {
         if (this.fitYData) {
           maxYAxis = ({ max }) => Math.max(max, this.maxYAxis!);
         }
       } else if (this.logarithmicScale) {
-        maxYAxis = ({ max }) => Math.ceil(max > 0 ? max * 1.05 : max * 0.95);
+        maxYAxis = ({ max }) => {
+          const value = max > 0 ? max * 1.05 : max * 0.95;
+          return Math.abs(value) < 1 ? value : Math.ceil(value);
+        };
       }
       this._chartOptions = {
         xAxis: {
@@ -753,10 +759,10 @@ export class StateHistoryChartLine extends LitElement {
     if (this.logarithmicScale) {
       // log(0) is -Infinity, so we need to set a minimum value
       if (typeof value === "number") {
-        return Math.max(value, 0.1);
+        return Math.max(value, Number.EPSILON);
       }
       if (typeof value === "function") {
-        return (values: any) => Math.max(value(values), 0.1);
+        return (values: any) => Math.max(value(values), Number.EPSILON);
       }
     }
     return value;
diff --git a/src/components/chart/statistics-chart.ts b/src/components/chart/statistics-chart.ts
index ea8469653a..a1b7e30dc9 100644
--- a/src/components/chart/statistics-chart.ts
+++ b/src/components/chart/statistics-chart.ts
@@ -241,14 +241,20 @@ export class StatisticsChart extends LitElement {
         minYAxis = ({ min }) => Math.min(min, this.minYAxis!);
       }
     } else if (this.logarithmicScale) {
-      minYAxis = ({ min }) => Math.floor(min > 0 ? min * 0.95 : min * 1.05);
+      minYAxis = ({ min }) => {
+        const value = min > 0 ? min * 0.95 : min * 1.05;
+        return Math.abs(value) < 1 ? value : Math.floor(value);
+      };
     }
     if (typeof maxYAxis === "number") {
       if (this.fitYData) {
         maxYAxis = ({ max }) => Math.max(max, this.maxYAxis!);
       }
     } else if (this.logarithmicScale) {
-      maxYAxis = ({ max }) => Math.ceil(max > 0 ? max * 1.05 : max * 0.95);
+      maxYAxis = ({ max }) => {
+        const value = max > 0 ? max * 1.05 : max * 0.95;
+        return Math.abs(value) < 1 ? value : Math.ceil(value);
+      };
     }
     const endTime = this.endTime ?? new Date();
     let startTime = this.startTime;
@@ -619,10 +625,10 @@ export class StatisticsChart extends LitElement {
     if (this.logarithmicScale) {
       // log(0) is -Infinity, so we need to set a minimum value
       if (typeof value === "number") {
-        return Math.max(value, 0.1);
+        return Math.max(value, Number.EPSILON);
       }
       if (typeof value === "function") {
-        return (values: any) => Math.max(value(values), 0.1);
+        return (values: any) => Math.max(value(values), Number.EPSILON);
       }
     }
     return value;