GraphNG: implement softMin/softMax for auto-scaling stabilization. close #979. (#30326)

packages/grafana-ui/package.json

@@ -72,7 +72,7 @@
     "react-transition-group": "4.4.1",
     "slate": "0.47.8",
     "tinycolor2": "1.4.1",
-    "uplot": "1.6.0"
+    "uplot": "1.6.1"
   },
   "devDependencies": {
     "@rollup/plugin-commonjs": "16.0.0",

packages/grafana-ui/src/components/GraphNG/GraphNG.tsx

@@ -163,6 +163,8 @@ export const GraphNG: React.FC<GraphNGProps> = ({
           log: customConfig.scaleDistribution?.log,
           min: field.config.min,
           max: field.config.max,
+          softMin: customConfig.axisSoftMin,
+          softMax: customConfig.axisSoftMax,
         });
 
         builder.addAxis({

packages/grafana-ui/src/components/uPlot/config.ts

@@ -112,6 +112,8 @@ export interface AxisConfig {
   axisPlacement?: AxisPlacement;
   axisLabel?: string;
   axisWidth?: number; // pixels ideally auto?
+  axisSoftMin?: number;
+  axisSoftMax?: number;
   scaleDistribution?: ScaleDistributionConfig;
 }
 

packages/grafana-ui/src/components/uPlot/config/UPlotScaleBuilder.ts

@@ -1,4 +1,4 @@
-import uPlot, { Scale } from 'uplot';
+import uPlot, { Scale, Range } from 'uplot';
 import { PlotConfigBuilder } from '../types';
 import { ScaleDistribution } from '../config';
 
@@ -7,6 +7,8 @@ export interface ScaleProps {
   isTime?: boolean;
   min?: number | null;
   max?: number | null;
+  softMin?: number | null;
+  softMax?: number | null;
   range?: () => number[]; // min/max
   distribution?: ScaleDistribution;
   log?: number;
@@ -18,26 +20,8 @@ export class UPlotScaleBuilder extends PlotConfigBuilder<ScaleProps, Scale> {
     this.props.max = optMinMax('max', this.props.max, props.max);
   }
 
-  // uPlot range function
-  range = (u: uPlot, dataMin: number, dataMax: number, scaleKey: string) => {
-    const { min, max } = this.props;
-
-    const scale = u.scales[scaleKey];
-
-    let smin, smax;
-
-    if (scale.distr === 1) {
-      [smin, smax] = uPlot.rangeNum(min ?? dataMin, max ?? dataMax, 0.1 as any, true);
-    } else if (scale.distr === 3) {
-      /**@ts-ignore (uPlot 1.4.7 typings are wrong and exclude logBase arg) */
-      [smin, smax] = uPlot.rangeLog(min ?? dataMin, max ?? dataMax, scale.log, true);
-    }
-
-    return [min ?? smin, max ?? smax];
-  };
-
   getConfig() {
-    const { isTime, scaleKey, range } = this.props;
+    const { isTime, scaleKey, min: hardMin, max: hardMax, softMin, softMax, range } = this.props;
     const distribution = !isTime
       ? {
           distr: this.props.distribution === ScaleDistribution.Logarithmic ? 3 : 1,
@@ -45,11 +29,58 @@ export class UPlotScaleBuilder extends PlotConfigBuilder<ScaleProps, Scale> {
         }
       : {};
 
+    // uPlot's default ranging config for both min & max is {pad: 0.1, hard: null, soft: 0, mode: 3}
+    let softMinMode: Range.SoftMode = softMin == null ? 3 : softMin === 0 ? 1 : 2;
+    let softMaxMode: Range.SoftMode = softMax == null ? 3 : softMax === 0 ? 1 : 2;
+
+    const rangeConfig: Range.Config = {
+      min: {
+        pad: 0.1,
+        hard: hardMin ?? -Infinity,
+        soft: softMin || 0,
+        mode: softMinMode,
+      },
+      max: {
+        pad: 0.1,
+        hard: hardMax ?? Infinity,
+        soft: softMax || 0,
+        mode: softMaxMode,
+      },
+    };
+
+    // uPlot range function
+    const rangeFn = (u: uPlot, dataMin: number, dataMax: number, scaleKey: string) => {
+      const scale = u.scales[scaleKey];
+
+      let minMax = [dataMin, dataMax];
+
+      let hardMinOnly = softMin == null && hardMin != null;
+      let hardMaxOnly = softMax == null && hardMax != null;
+
+      if (scale.distr === 1) {
+        // @ts-ignore here we may use hardMin / hardMax to make sure any extra padding is computed from a more accurate delta
+        minMax = uPlot.rangeNum(hardMinOnly ? hardMin : dataMin, hardMaxOnly ? hardMax : dataMax, rangeConfig);
+      } else if (scale.distr === 3) {
+        minMax = uPlot.rangeLog(dataMin, dataMax, scale.log ?? 10, true);
+      }
+
+      // if all we got were hard limits, treat them as static min/max
+      if (hardMinOnly) {
+        minMax[0] = hardMin!;
+      }
+
+      if (hardMaxOnly) {
+        minMax[1] = hardMax!;
+      }
+
+      return minMax;
+    };
+
     return {
       [scaleKey]: {
         time: isTime,
         auto: !isTime,
-        range: range ?? this.range,
+        range: range ?? rangeFn,
         ...distribution,
       },
     };

public/app/plugins/panel/timeseries/config.ts

@@ -175,6 +175,22 @@ export function getGraphFieldConfig(cfg: GraphFieldConfig): SetFieldConfigOption
           },
           showIf: c => c.axisPlacement !== AxisPlacement.Hidden,
         })
+        .addNumberInput({
+          path: 'axisSoftMin',
+          name: 'Soft min',
+          category: ['Axis'],
+          settings: {
+            placeholder: 'See: Standard options > Min',
+          },
+        })
+        .addNumberInput({
+          path: 'axisSoftMax',
+          name: 'Soft max',
+          category: ['Axis'],
+          settings: {
+            placeholder: 'See: Standard options > Max',
+          },
+        })
         .addCustomEditor<void, ScaleDistributionConfig>({
           id: 'scaleDistribution',
           path: 'scaleDistribution',

yarn.lock

@@ -25540,10 +25540,10 @@ update-notifier@^2.5.0:
     semver-diff "^2.0.0"
     xdg-basedir "^3.0.0"
 
-uplot@1.6.0:
-  version "1.6.0"
-  resolved "https://registry.yarnpkg.com/uplot/-/uplot-1.6.0.tgz#c91317d4defcf0406c9fb1cbbfcabc2dcaa78230"
-  integrity sha512-Xv25lGDHB5MdUwVwO8MDbhzyCrg6bgfiQwBBzLF9xhwyQStzTLzQlQarmYUkuzEjrHMRkH2vvLnK1XvjiNeDbw==
+uplot@1.6.1:
+  version "1.6.1"
+  resolved "https://registry.yarnpkg.com/uplot/-/uplot-1.6.1.tgz#68f2e5118c2b66490ba097155e0a753331fc2e4d"
+  integrity sha512-wg6CVWEq9WDHssw3jd0jMmJ7dWSVmfaYazcuad4d3cyiJoTxcSjUEp5Q9TiDzmPhJASjk77orh2+r/6WS9Uz7A==
 
 upper-case@^1.1.1:
   version "1.1.3"