DP44/enriched-partialglm/DTS Viewer/DTS.Viewer.Modules/DTS.Viewer.AddCalculatedChannel/ViewModel.md

source_files, generated_at, model, schema_version, sha256

source_files	generated_at	model	schema_version	sha256
DTS Viewer/DTS.Viewer.Modules/DTS.Viewer.AddCalculatedChannel/ViewModel/AddCalculatedChannelViewModel.cs	2026-04-16T11:21:00.745415+00:00	zai-org/GLM-5-FP8	1	5cfd5d272102b3bf

Documentation: AddCalculatedChannelViewModel

1. Purpose

This module provides a ViewModel for the "Add Calculated Channel" feature in the DTS Viewer application. It enables users to create derived data channels from existing test data by applying mathematical transformations (integrals, derivatives, trigonometric functions) or specialized biomechanical calculations (HIC, 3D IR-Tracc, Resultant). The ViewModel manages channel selection UI state, validates user inputs, orchestrates the calculated channel creation via CalculatedChannelCreator, and persists changes back to .dts test files.

---

2. Public Interface

Public Properties

Property	Type	Description
View	IBaseView	The associated view instance.
Parent	IBaseViewModel	Reference to the parent ViewModel.
ContextSearchRegion	object	Placeholder for context search region.
NotificationRequest	InteractionRequest<Notification>	Raises notification dialogs.
ConfirmationRequest	InteractionRequest<Confirmation>	Raises confirmation dialogs.
HeaderInfo	string	Returns "AddCalculatedChannelRegion".
IsBusy	bool	Throws NotImplementedException on get/set.
IsDirty	bool	Throws NotImplementedException on get.
IsAddCalculatedChannelIncluded	bool	Feature inclusion flag.
IncludeGroupNameInISOExport	bool	Controls ISO export formatting.
DefaultDTSEncoding	int	Encoding code page for DTS file operations.
ChannelName	string	Name for the new calculated channel.
ChannelDescription	string	Auto-generated description based on selected calculation and channels.
IsoCode	string	ISO code for the channel (defaults to "NONE").
SingleChannelSelectorVisibility	bool	Controls visibility for single-channel selection UI.
HICChannelSelectorVisibility	bool	Controls visibility for HIC channel selection UI.
MultipleChannelSelectorVisibility	bool	Controls visibility for multi-channel selection UI.
ThreeDIRTRACCVisibility	bool	Controls visibility for 3D IR-Tracc selection UI.
CalculationList	CalculationHelper[]	Lazy-initialized list of available calculations.
SelectedCalculation	CalculationHelper	Currently selected calculation type.
ChannelList	ObservableCollection<ITestChannel>	All available input channels.
ChannelListObjects	ObservableCollection<ChannelHelper>	Wrapped channel objects with IsIncluded selection state.
AvailableHICChannels	ChannelHelper[]	Channels with acceleration units valid for HIC calculation.
HICAccelerationX/Y/Z	ChannelHelper	Selected X/Y/Z acceleration channels for HIC.
HICLength	int	HIC calculation length (default: 16).
SourceChannel	ITestChannel	Selected source channel for single-channel calculations.
IRTraccChannelList	ObservableCollection<ChannelHelper>	Valid IR-Tracc channels.
IRTraccChannel	ChannelHelper	Selected IR-Tracc channel.
Pot1ChannelList/Pot2ChannelList	ObservableCollection<ChannelHelper>	Valid potentiometer channels.
Pot1Channel/Pot2Channel	ChannelHelper	Selected potentiometer channels.

Public Commands

Command	Handler	Description
AddCalculatedChannelCommand	AddCalculatedChannel(object obj)	Validates inputs, creates calculated channel(s), and saves to .dts file.

Public Methods

Method	Signature	Description
PublishChanges	void PublishChanges()	Not implemented (contains commented-out NotImplementedException).
Initialize	void Initialize()	Calls Initialize(null).
Initialize	void Initialize(object parameter)	Sets Parent from parameter and subscribes to events.
Activated	void Activated()	Resets UI state: sets default source channel, ISO code, calculation, and channel name.
Cleanup	void Cleanup()	Empty implementation.
Validate	bool Validate(ref List<string> errors, ref List<string> warnings, bool displayWindow)	Validates channel name and calculation-specific requirements.

Public Enums

Calculation

Defines available calculation types with Description attributes for display:

Value	Description
Integral = 0	"Integral"
DoubleIntegral = 1	"Double Integral"
Derivative = 2	"Derivative"
Sin = 3	"Sin"
Cos = 4	"Cos"
ThreeDIRTracc = 5	"3D IR-Tracc"
SUM = 6	"SUM"
AVE = 7	"Average"
ThreeDIRTraccAbdomen = 8	"3D IR-TRACC Abdomen"
ThreeDIRTraccLowerThorax = 9	"3D IR-TRACC Lower Thorax"
Resultant = 10	"Resultant"
HIC = 11	"HIC"

Public Nested Classes

ChannelHelper : BasePropertyChanged

Wraps ITestChannel for UI binding with DisplayName formatting based on IsoViewModeStatic.ViewMode and IsIncluded selection state.

CalculationHelper

Wraps a Calculation enum value with localized string display via StringResources.ResourceManager.GetString("CALCULATION_" + MyCalculation).

---

3. Invariants

1. Channel Name Validation: ValidateChannelName() returns true only if ChannelName is not null or empty.

2. HIC Calculation Requirements: ValidateHIC() requires all three acceleration channels (HICAccelerationX, HICAccelerationY, HICAccelerationZ) to be non-null.

3. Resultant Calculation Requirements: ValidateResultant() requires:

   • At least one channel with IsIncluded == true
   • All included channels must have matching SensitivityUnits
   • All included channels must have matching SampleRateHz

4. Display Order: New calculated channels are assigned maxDisplayOrder + 1 from existing channels.

5. Channel Uniqueness: ChannelList excludes duplicate channels by ChannelId during population.

6. IR-Tracc Channel Filtering: Channels appear in IRTraccChannelList only if:

   • ChannelType is Test.Module.AnalogInputChannel
   • LinearizationFormula is valid per LinearizationFormula.IsValid()
   • ZeroMethod equals ZeroMethodType.None
   • ZeroPoint != 0
   • FactoryExcitationVoltage != 0

7. Potentiometer Channel Filtering: Channels appear in Pot1ChannelList/Pot2ChannelList only if:

   • ChannelType is Test.Module.AnalogInputChannel
   • Eu is "deg" or "deg-ang" (case-insensitive, trimmed)
   • ZeroMethod equals ZeroMethodType.None
   • FactoryExcitationVoltage != 0

---

4. Dependencies

This Module Depends On

• DTS.Common - Constants, utilities
• DTS.Common.Base - BaseViewModel<T>, BasePropertyChanged
• DTS.Common.Classes.Viewer.Commands - RelayCommand
• DTS.Common.DAS.Concepts - Data concepts
• DTS.Common.Enums.Sensors - ZeroMethodType
• DTS.Common.Events - Event types (RaiseNotification, TestSummaryChangeNotification, PageErrorEvent, SetSaveButton, RefreshTestRequestEvent)
• DTS.Common.Interactivity - InteractionRequest<T>, Notification, Confirmation
• DTS.Common.Interface - IAddCalculatedChannelViewModel, IBaseView, IBaseViewModel, ITestChannel
• DTS.Common.Utilities.Logging - APILogger
• DTS.Common.Utils - Utils class for channel info loading
• DTS.Slice.Control - Slice control functionality
• DTS.Viewer.AddCalculatedChannel.Model - Model types (inferred)
• DTS.Serialization - Test, TestSetup, SliceRaw.File
• Prism.Events - IEventAggregator
• Prism.Regions - IRegionManager
• Unity - IUnityContainer

Events Subscribed

• RaiseNotification → OnRaiseNotification
• TestSummaryChangeNotification → OnTestSummaryChanged

Events Published

• RaiseNotification
• PageErrorEvent
• SetSaveButton
• RefreshTestRequestEvent

---

5. Gotchas

1. IsBusy and IsDirty Throw Exceptions: Both properties throw NotImplementedException. Code paths that access these will fail at runtime.

2. HIC Save Button Logic Appears Inverted: In UpdateSaveButtonVisibility(), the HIC case sets IsUsable = true when acceleration channels are null and IsUsable = false when they are not null. This contradicts the validation logic in ValidateHIC() which requires non-null channels. This appears to be a bug.

3. File Backup Behavior: The .dts backup file (with BACKUP_FILE_EXTENSION) is created only if one doesn't already exist. The backup is deleted after successful save only if it was created during that save operation.

4. Hardcoded Thread.Sleep: A Thread.Sleep(10) exists after file writing in AddCalculatedChannel(). Purpose is unclear from source alone.

5. Lazy Channel Loading: In OnTestSummaryChanged(), if ts.Channels.FirstOrDefault() == null, channels are loaded on-demand via Utils.SetChannelInfo(). This side effect may not be obvious to callers.

6. Duplicate Calculated Channel Handling: AddCalculatedChannelToTest() silently overwrites existing calculated channels with matching ChannelId by removing the duplicate before adding the new one. A log message is generated but no user confirmation is requested.

7. PublishChanges() Not Implemented: The method body contains only a commented-out NotImplementedException. It is unclear if this is intentional or incomplete.