Common instrument controls

Almost every editor is built from the same instrument faceplate as the sine-wave window. This page describes the shared fields. Waveform-specific sliders and renamed dials are documented with each signal.

1. Signal type

Two exclusive checkboxes select the numeric representation used in memory and on disk:

ModeEditor ranges (typical waves)In-memory arraySaved array
Floating-point (default) Amplitude 0–10 V; DC −10 to +10 V float64 float32
Fixed-point Amplitude 0–10000; DC −10000 to +10000 (integer counts) int32 (rounded) int16, clipped to [−32768, 32767]

Fixed-point uses a display scale of 1000 counts per volt, so 10 V maps to 10000. White-noise editors do not switch to volt ranges: scale, variance, and sequence mean stay unitless in both modes (see White noise).

2. Identity row

FieldMeaning
Signal name Base file name (no extension). If empty, SigGer uses the waveform key (for example sine_wave).
Destination Folder only. Use Browse… — a directory picker, not a file picker. New windows start with the default destination from Configuration if one has been saved.

3. Rotary dials

Silver instrument knobs travel clockwise from about 7 o’clock (minimum) to 5 o’clock (maximum). Logarithmic dials are used for frequencies that span decades. Linear dials are used when the minimum is zero (digital frequency, variance, plateau duration, scale factor).

Typical dialRangeScale
Amplitude0–10 V (float) or 0–10000 (fixed)Linear
Waveform frequency1 Hz up to fs/2Logarithmic
Sampling frequency1 kHz – 192 kHz (factory default 48 kHz; Configurable under Configuration → Default parameters)Logarithmic

Each dial has a green numeric readout. Editing the readout and pressing Enter commits the value (clamped to the legal range).

4. Nyquist limit

For every periodic editor and for the damped-sine window, the waveform frequency f cannot exceed half the sampling rate:

0 < f ≤ fs / 2 (2)

This is the classical sampling theorem bound for a real sinusoid (Nyquist–Shannon). When you turn fs down, SigGer immediately lowers the frequency dial’s maximum. Sweep frequencies are specified as percentages of fs/2 and must satisfy f1 < f2 < fs/2.

Digital frequency on the discrete damped sinusoid is not capped by fs/2; its natural bound is already ω ∈ [0, π] rad/sample.

5. Oscilloscope preview

The green trace is a schematic preview of the shape, not a full N-sample render. It updates as you move dials and sliders. Use it to check polarity, delay, duty, and envelope — not for metrology.

6. Target format and number of samples

ControlValues
Target format tumbler HDF5, Parquet, Matlab
Number of samples tumbler 256, 512, 1024 (default), 2048, 4096, 8192, 16384, 32768, 65536, 131072, 262144
Samples edit Any integer from 16 to 10 000 000; the tumbler snaps when the value matches a preset

Record length in seconds is

Trec = N / fs (3)

7. DC level (or sequence mean)

A horizontal slider adds a constant to every sample. On ordinary waveform editors the unit is volts (or integer counts in fixed-point). On noise editors the same slider is the sequence mean μ ∈ [−100, 100], unitless.

8. Progress gauge, status, Run and Close

ControlBehaviour
Circular gauge Receives 10, 20, …, 100 from the generator’s progress_callback.
Status Shows “Synthesizing…”, the saved path, or an error message.
Run Validates destination, synthesizes, writes the file, re-enables the button.
Close Hides that instrument window. The control bar stays open.

Phase for periodic oscillators is computed in normalized form so it does not wrap poorly at large n:

p[n] = (n · f / fs) mod 1 ,   then · 2π for sinusoids (4)

8. Application defaults

Configuration → Configure default parameters edits the values that every new instrument window starts with: destination folder, target format, number of samples, sampling frequency, and floating-point versus fixed-point. Saving writes sigger_config.json in the SigGer folder. On startup SigGer reads that file if it exists; if it is missing, factory values are used (empty destination, HDF5, 1024 samples, 48 kHz, floating-point). Already-open editors keep the values they were opened with.

Configuration → Configure the system appearance chooses a named theme (Factory, Midnight, Ivory, Laboratory, High contrast) or a custom mix of interface font, readout font, and colors. Saving writes sigger_appearance.json and restyles open windows immediately. The main control-bar window itself is not given a Qt stylesheet, so native dragging on Windows is preserved.