The log analyzer

The log analyzer loads one or more data logs and plots their channels over time, so you can see what the engine was actually doing. Open it from Analysis › Log Analyzer. This page covers the analyzer window itself; getting a log in is on importing logs, and playing a log back over your maps is on replaying logs over your maps.

Figure 1

The toolbar

The toolbar across the top holds the window’s actions:

• Open Log… — load a log file (.csv, .tsv, .txt, .msl or .log); the import wizard handles the parsing.
• Close Active Log — remove the currently selected log.
• Reset View — fit the plot back to the full extent of the data.
• Save as New Preset… / Update Preset… — save the channel setup as a reusable preset; the button reads “Update” when the active log already matched one.
• Export… — write the visible channels over the currently visible range to a file (the active log only).
• Screenshot… — save the plot as a PNG or JPEG image.
• Replay through maps… — open the replay tool to play the log over your maps.

Two checkboxes, Overlay all logs and Align starts, control how multiple logs are shown (below).

Holding several logs

You can load more than one log at a time. The Loaded logs list shows them all; the one you select is the active log, and it drives the channel table and the statistics. Two checkboxes change how they plot together:

• Overlay all logs — draw every loaded log on the same plot, each distinguished by line style (the first solid, the next dashed, then dotted, and so on) so you can compare runs directly.
• Align starts — shift each log so they all begin at the same point on the X axis, which lines up runs that were recorded at different times.

Channels (active log)

The Channels (active log) table lists the active log’s channels in five columns: Show (a checkbox to plot it or not), Color (double-click the swatch to change the line colour), Name, Unit and Group. Channels assigned to the same group (double-click the Group cell to set it) share one Y axis and scale, so related signals sit together and unrelated ones do not fight over a single scale. The channel that is the X axis is marked and cannot be hidden. On import the editor auto-enables the “common four” — RPM, MAP, TPS and AFR — when it recognises them.

The plot

The plot is a multi-axis time-series chart. Each group gets its own Y axis, stacked outward from the chart (the first group on the left, the next on the right, and so on), while the X axis — usually time — is shared by all of them. To move around: drag left/right to pan, scroll the mouse wheel to zoom around the cursor, and use Reset View to fit everything again. A crosshair readout follows the pointer, and very dense logs are automatically thinned to what the screen can show so the chart stays responsive without losing its shape.

Statistics (visible range)

The Statistics (visible range) panel reports each visible channel’s Min, Max, Mean, Stddev and sample count (N), with its Unit. The figures are computed over the part of the log currently on screen, so zooming into a single pull or a steady cruise gives you the statistics for just that span.

Tip — put related channels in the same group so they share a sensible scale, and keep unrelated ones (say RPM and AFR) in separate groups so neither gets flattened. Then zoom to the section you care about and read the statistics for exactly that range.

See also

• Importing logs — the wizard and presets.
• Replaying logs over your maps — the live cell overlay.
• The map editor