From 6e39242ca3cf1c439f8f6c583db553526f072ae8 Mon Sep 17 00:00:00 2001
From: Petar Petrov <MindFreeze@users.noreply.github.com>
Date: Fri, 31 Jan 2025 16:44:22 +0200
Subject: [PATCH] Echarts: fix Y scaling (#23988)

* Echarts: fix scaling of Y axis

* fix fit logic to only extend the limits

* handle invalid min for log scale
---
 src/components/chart/state-history-chart-line.ts | 15 +++++++++++++--
 src/components/chart/statistics-chart.ts         | 12 +++++++++---
 2 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/src/components/chart/state-history-chart-line.ts b/src/components/chart/state-history-chart-line.ts
index 4c31a9b234..f55c205000 100644
--- a/src/components/chart/state-history-chart-line.ts
+++ b/src/components/chart/state-history-chart-line.ts
@@ -187,6 +187,11 @@ export class StateHistoryChartLine extends LitElement {
     ) {
       const dayDifference = differenceInDays(this.endTime, this.startTime);
       const rtl = computeRTL(this.hass);
+      const minYAxis =
+        // log(0) is -Infinity, so we need to set a minimum value
+        this.logarithmicScale && typeof this.minYAxis === "number"
+          ? Math.max(this.minYAxis, 0.1)
+          : this.minYAxis;
       this._chartOptions = {
         xAxis: {
           type: "time",
@@ -213,8 +218,14 @@ export class StateHistoryChartLine extends LitElement {
         yAxis: {
           type: this.logarithmicScale ? "log" : "value",
           name: this.unit,
-          min: this.fitYData ? this.minYAxis : undefined,
-          max: this.fitYData ? this.maxYAxis : undefined,
+          min:
+            this.fitYData && typeof minYAxis === "number"
+              ? ({ min }) => Math.min(min, minYAxis!)
+              : minYAxis,
+          max:
+            this.fitYData && typeof this.maxYAxis === "number"
+              ? ({ max }) => Math.max(max, this.maxYAxis!)
+              : this.maxYAxis,
           position: rtl ? "right" : "left",
           scale: true,
           nameGap: 2,
diff --git a/src/components/chart/statistics-chart.ts b/src/components/chart/statistics-chart.ts
index 283055cabd..f35d1cdcbb 100644
--- a/src/components/chart/statistics-chart.ts
+++ b/src/components/chart/statistics-chart.ts
@@ -251,9 +251,15 @@ export class StatisticsChart extends LitElement {
         },
         position: computeRTL(this.hass) ? "right" : "left",
         // @ts-ignore
-        scale: this.chartType !== "bar",
-        min: this.fitYData ? undefined : this.minYAxis,
-        max: this.fitYData ? undefined : this.maxYAxis,
+        scale: true,
+        min:
+          this.fitYData && typeof this.minYAxis === "number"
+            ? ({ min }) => Math.min(min, this.minYAxis!)
+            : this.minYAxis,
+        max:
+          this.fitYData && typeof this.maxYAxis === "number"
+            ? ({ max }) => Math.max(max, this.maxYAxis!)
+            : this.maxYAxis,
         splitLine: {
           show: true,
           lineStyle: splitLineStyle,