Support scaling_factor and offset for axis

Author: loichuder

packages/app/src/vis-packs/nexus/NxValuesFetcher.tsx

@@ -43,7 +43,22 @@ function NxValuesFetcher<T extends NumericLikeType | ComplexType>(
   const errors = useDatasetValue(signalDef.errorDataset, selection);
   const auxValues = useDatasetsValues(auxDatasets, selection);
   const auxErrors = useDatasetsValues(auxErrorDatasets, selection);
-  const axisValues = useDatasetsValues(axisDatasets);
+  const rawAxisValues = useDatasetsValues(axisDatasets);
+  const axisValues = rawAxisValues.map((value, i) => {
+    const axisScalingFactor = axisDefs[i]?.scalingFactor;
+    const axisOffset = axisDefs[i]?.offset;
+    if (value && (axisScalingFactor || axisOffset)) {
+      const offset = axisOffset ?? 0;
+      const scalingFactor = axisScalingFactor ?? 1;
+      const scaledValue: number[] = [];
+      value.forEach((v) => {
+        scaledValue.push(scalingFactor * Number(v) + offset);
+      });
+      return scaledValue;
+    }
+
+    return value;
+  });
 
   return render({ title, signal, errors, auxValues, auxErrors, axisValues });
 }

packages/app/src/vis-packs/nexus/hooks.ts

@@ -19,13 +19,14 @@ import {
   findTitleDataset,
   getDatasetInfo,
   getDefaultSlice,
+  getScalingInfo,
   getSilxStyle,
 } from './utils';
 
 export const useDefaultSlice = createMemo(getDefaultSlice);
 
 export function useNxData(group: GroupWithChildren): NxData {
-  const { attrValuesStore } = useDataContext();
+  const { attrValuesStore, valuesStore } = useDataContext();
 
   assertNxDataGroup(group, attrValuesStore);
   const signalDataset = findSignalDataset(group, attrValuesStore);
@@ -46,7 +47,11 @@ export function useNxData(group: GroupWithChildren): NxData {
     })),
     axisDefs: axisDatasets.map(
       (dataset) =>
-        dataset && { dataset, ...getDatasetInfo(dataset, attrValuesStore) },
+        dataset && {
+          dataset,
+          ...getDatasetInfo(dataset, attrValuesStore),
+          ...getScalingInfo(group, dataset.name, valuesStore),
+        },
     ),
     defaultSlice: useDefaultSlice(group, signalDataset.shape, attrValuesStore),
     silxStyle: getSilxStyle(group, attrValuesStore),

packages/app/src/vis-packs/nexus/models.ts

@@ -28,6 +28,11 @@ export interface DatasetInfo {
   unit: string | undefined;
 }
 
+export interface ScalingInfo {
+  scalingFactor: number | undefined;
+  offset: number | undefined;
+}
+
 export interface DatasetDef<
   T extends NumericLikeType | ComplexType = NumericLikeType | ComplexType,
 > extends DatasetInfo {
@@ -38,7 +43,7 @@ type WithError<T extends DatasetDef> = T & {
   errorDataset?: Dataset<ArrayShape, NumericType>;
 };
 
-export type AxisDef = DatasetDef<NumericType>;
+export type AxisDef = DatasetDef<NumericType> & ScalingInfo;
 
 export type DefaultSlice = (number | '.')[];
 export interface SilxStyle {

packages/app/src/vis-packs/nexus/utils.test.ts

@@ -5,9 +5,27 @@ import { describe, expect, it } from 'vitest';
 import { applyDefaultSlice, guessKeepRatio } from './utils';
 
 const axisDataset = dataset('foo', intType(), [5]);
-const axisDefNoUnit = { label: 'foo', unit: undefined, dataset: axisDataset };
-const axisDefUnitX = { label: 'foo', unit: 'mm', dataset: axisDataset };
-const axisDefUnitY = { label: 'foo', unit: 'degrees', dataset: axisDataset };
+const axisDefNoUnit = {
+  label: 'foo',
+  unit: undefined,
+  dataset: axisDataset,
+  scalingFactor: undefined,
+  offset: undefined,
+};
+const axisDefUnitX = {
+  label: 'foo',
+  unit: 'mm',
+  dataset: axisDataset,
+  scalingFactor: undefined,
+  offset: undefined,
+};
+const axisDefUnitY = {
+  label: 'foo',
+  unit: 'degrees',
+  dataset: axisDataset,
+  scalingFactor: undefined,
+  offset: undefined,
+};
 
 describe('guessKeepRatio', () => {
   it('should return `cover` if units of both axes are provided and equal', () => {

packages/app/src/vis-packs/nexus/utils.ts

@@ -26,12 +26,13 @@ import {
 } from '@h5web/shared/hdf5-models';
 import { getChildEntity } from '@h5web/shared/hdf5-utils';
 
-import { type AttrValuesStore } from '../../providers/models';
+import { type AttrValuesStore, type ValuesStore } from '../../providers/models';
 import { hasAttribute } from '../../utils';
 import {
   type AxisDef,
   type DatasetInfo,
   type DefaultSlice,
+  type ScalingInfo,
   type SilxStyle,
 } from './models';
 
@@ -130,6 +131,38 @@ export function findAuxErrorDataset(
   return dataset;
 }
 
+export function findScalingFactor(
+  group: GroupWithChildren,
+  datasetName: string,
+): Dataset<ScalarShape, NumericType> | undefined {
+  const dataset = getChildEntity(group, `${datasetName}_scaling_factor`);
+
+  if (!dataset) {
+    return undefined;
+  }
+
+  assertDataset(dataset);
+  assertScalarShape(dataset);
+  assertNumericType(dataset);
+  return dataset;
+}
+
+export function findOffset(
+  group: GroupWithChildren,
+  datasetName: string,
+): Dataset<ScalarShape, NumericType> | undefined {
+  const dataset = getChildEntity(group, `${datasetName}_offset`);
+
+  if (!dataset) {
+    return undefined;
+  }
+
+  assertDataset(dataset);
+  assertScalarShape(dataset);
+  assertNumericType(dataset);
+  return dataset;
+}
+
 export function findAssociatedDatasets(
   group: GroupWithChildren,
   type: 'axes' | 'auxiliary_signals',
@@ -312,6 +345,27 @@ export function getSilxStyle(
   }
 }
 
+export function getScalingInfo(
+  group: GroupWithChildren,
+  datasetName: string,
+  valuesStore: ValuesStore,
+): ScalingInfo {
+  const scalingFactorDataset = findScalingFactor(group, datasetName);
+  const scalingFactor = scalingFactorDataset
+    ? Number(valuesStore.get({ dataset: scalingFactorDataset }))
+    : undefined;
+
+  const offsetDataset = findOffset(group, datasetName);
+  const offset = offsetDataset
+    ? Number(valuesStore.get({ dataset: offsetDataset }))
+    : undefined;
+
+  return {
+    scalingFactor,
+    offset,
+  };
+}
+
 export function getDatasetInfo(
   dataset: Dataset,
   attrValuesStore: AttrValuesStore,