Zelos

How-ToNotebooksMade with Zelos app 26.0.9

Re-run a notebook on a new time window

Change a notebook's time window from the sidebar, run it again with Run all, and re-run only the changed cells with Run out-of-date cells.

Michael Jaradah3 minute read
Ten minutes of cell_3's sawtooth, with two windows reaching back from the notebook at now: -1m, and -10m in violet.
Contents8 sections

Your notebook from Write your first notebook and chart live signals asks about the last two minutes, and the window is typed into the code. To ask about another stretch of time, you would edit code. A parameter moves the window out of the code. Change one value in the sidebar, run again, and the same cells answer for the new window. This guide does that over one minute and then ten, and shows which button re-runs what.

This guide runs on simulated data. Install the CLI shows how to start it.

A parameter is a value in the file

A notebook is a Markdown file in your notebooks folder. Its front matter, the block between two --- lines at the top, holds settings for the whole notebook. A parameter is one of them: a name and a value. Cells read it as params.window, and the agent sets it before every run. The Notebooks sidebar edits the block for you. The value -10m means ten minutes before now.

The question here is how long the weak cell sat under 3.0 V. In this example, cell_3 dips under 3.0 V near the end of every minute, so a longer window holds more of those stretches.

Ten minutes of cell_3's voltage drawn as a sawtooth, with the stretch under 3.0 V lit in each minute, and a one-minute and a ten-minute window under it.
The two windows this guide runs, with the counts it measured.

Before you start

  • The Zelos app.
  • Some recorded data. Ten minutes fills the ten-minute window.

Step 1: Add a window parameter

Open the Cell voltages notebook. With a notebook tab active, the Notebooks sidebar shows PARAMETERS and PYTHON. In the blank row under PARAMETERS, type window in the name cell and -1m in the value cell, then press Enter.

The PARAMETERS section with one row, window set to -1m, and the blank row below it.

Step 2: Read the window in the cells

Change the query cell to read the parameter:

cells = agent.query("bus0/BMS_message/cells.*", start=params.window)
cells

The chart's title still says two minutes, so let it name the window:

cells.short_names().plot(title=f"Cell voltages, {params.window}")

Then add a cell below it with Cmd+Shift+C (Ctrl+Shift+C on Windows and Linux) to count the samples under 3.0 V. A comparison gives a series of true and false, and .sum() counts the true ones. The pack reports once a second, so the count is in seconds:

weak = cells["bus0/BMS_message/cells.cell_3"]
(weak < 3.0).sum()

Step 3: Run all on two windows

Choose Run all. It runs every cell, top to bottom. Then type -10m in the window's value cell, press Enter, and choose Run all again. In this example the count went from 13 to 138.

The window row and the count cell for each run: -1m gave 13, -10m gave 138.
The window row and the count cell, cut from the capture after each run and stacked. The 1-minute count depends on where the window cuts the cycle.
Run all after the window change: the chart redraws ten minutes and the count goes from 13 to 138.

Step 4: Run only what changed

Change the floor in the count cell from 3.0 to 3.2. The cell gets an "Out of date" badge, and the status bar reads "1 cell out of date". Open the chevron next to Run all and choose Run out-of-date cells (Cmd+Shift+Enter). It runs from the first changed cell down, here only that cell, so the count still covers the same ten minutes.

The edited count cell with its Out of date badge, and the run menu open with Run out-of-date cells at the top.

Where people get stuck

  • Type the window as text, such as -10m or an ISO 8601 time. A bare 10 is saved as a number, which start= does not accept.
  • A window counts back from now, not from the timeline's playhead.
  • A parameter lives in the file. Changing it shows in a diff. The CLI's --param flag runs other values without an edit.

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