# Oscilloscope

> An oscilloscope for Python — several traces over a grid, a trigger that holds periodic waves still, XY Lissajous mode, phosphor persistence and glow.

Source: https://albakore.github.io/pyzed/audio/components/scope/

(Image: A two-trace oscilloscope with fading persistence next to an XY scope drawing a rotating Lissajous figure)

**In plain words:**

An oscilloscope draws a signal the way a lab instrument does: a few milliseconds of it on a
green grid. It is how you see the shape of a wave — sine, saw, square — while you patch.

```python
ui.audio.Scope(traces=[osc.scope(1024), lfo.scope(1024)], width=320, height=180)
```

## Traces and trigger

`traces` is a list of signals (or a single list of numbers), each drawn in the next color of
`colors`. With `trigger=True` each trace starts at the first point where the wave rises through
zero, so a steady tone stands still instead of drifting. `window` is how many samples are shown.

## XY mode

`xy=True` draws the first trace against the second: the first moves the dot left and right, the
second up and down. Two sines make **Lissajous figures**; a stereo pair (left, right) shows how
wide the stereo image is — a vertical line is mono, a cloud is wide.

## Phosphor

`persistence=3` leaves fading copies of the last three frames, like the glow of an old CRT
screen; `glow=True` adds a soft halo around the newest trace.

| Property | Default | What it does |
| --- | --- | --- |
| `traces` | `()` | Signals to draw (−1..1). |
| `width`, `height` | `320`, `180` | Size in pixels. |
| `colors` | `"scope"` | A palette name or a list (one color per trace). |
| `background` | `"#0b120e"` | The screen. |
| `columns`, `rows` | `8`, `6` | Divisions of the grid. |
| `gain` | `1` | Vertical zoom. |
| `trigger`, `window` | `True`, `512` | Holds periodic waves still; samples shown. |
| `xy` | `False` | Lissajous mode. |
| `persistence`, `glow` | `0`, `True` | Fading copies and halo. |