Compute Tab

The Compute tab lets you create derived signals from your COMTRADE recording. All computations run entirely in your browser using the raw sample data — no server calls, no delays.

Each computed signal becomes a new trace overlaid on the waveform viewer, updating in real time as you move the cursor. You can create multiple signals simultaneously and toggle their visibility independently.

The compute engine supports 35 signal types organized into 7 categories. Click any category card below to see the mathematical theory behind each signal.

The Signal Builder is the primary interface for creating computed signals. It provides a browsable, searchable catalog of all available signal templates.

Layout:

• Header with title, subtitle, and a badge showing the count of created signals
• Search input to filter signal templates across all categories by name or description
• Category tabs — 7 pill-style tabs (Basic, Sequence, Power, Frequency, Protection, Impedance, Differential). The active tab is highlighted in teal
• Template cards — displayed in a flat grid. Each card shows the signal name and required channel count
• Configuration card — appears when a template is selected, showing the signal description, channel selectors, optional parameters, an output mode toggle (when available), and an "Add Signal" button

Some signals offer an output mode toggle — a segmented control that switches how the signal is computed. A short description below the toggle explains the selected mode.

Signals with output modes:

Creating a Computed Signal

1. Navigate to the Compute tab in the viewer
2. Browse categories using the tab bar, or type in the search input to filter templates across all categories
3. Click a template card to select a signal type — the configuration card appears with a description and channel selectors
4. Choose the source channel(s) from the dropdowns — computed signals also appear as selectable sources under a "Computed Signals" group, enabling chaining
5. If the signal has an output mode toggle, choose the desired mode (e.g., Time Domain vs DFT)
6. Optionally adjust parameters (e.g., harmonic number, line impedance, CT ratios)
7. Click Add Signal — the signal is computed instantly and appears on the waveform viewer

Reading Results

• Created signals appear in the Computed Signals card below the Signal Builder, with an embedded waveform chart
• Each signal row shows: color dot, name, unit, category tag, and visibility/delete controls
• Move the cursor on the main waveform to read the instantaneous value at any time
• Toggle visibility on/off without deleting the signal
• Remove a signal when no longer needed

Computed signals can be used as inputs to other computed signals. When selecting source channels, a "Computed Signals" group appears in the channel dropdown alongside the original analog channels.

This enables multi-step analysis workflows. For example:

• Create a 3I₀ Residual from three-phase currents → use it as the input for Harmonic Extraction to isolate H2 of the residual current
• Create Subtraction to derive a line-to-line voltage → use it as the voltage input for Impedance |Z|
• Create Multiply by Constant to normalize a CT secondary current → feed it into Differential Current

Signals are recomputed in dependency order, so downstream signals automatically update when upstream inputs change.

Some categories offer batch-create buttons that generate multiple related signals in one click:

• "Create All Sequences" (Sequence tab) — creates positive, negative, and zero sequence signals from an auto-detected three-phase channel triplet
• "Create P, Q, S" (Power tab) — creates active, reactive, and apparent power from a matched voltage/current pair
• "Create 3V₀ + 3I₀" (Differential tab) — creates residual voltage and residual current from detected three-phase triplets

Batch creation auto-detects three-phase channel triplets by matching channel names (e.g., IA/IB/IC or Va/Vb/Vc). If multiple triplets are found, you can choose which one to use.