Pointing at a channel in the file tree now previews it. The channel is
drawn on its own in a large framed box over the middle of the plot area,
with the main plot dimmed around it, and it follows the pointer down the
list. The preview always shows the whole record, and when the main plot is
zoomed the zoomed span is shaded on it, so it reads as a map of where you
are. The title bar says what a click will do — Click to
add or Click to remove.
Under the preview, a Statistics panel gives the channel's minimum, maximum
and mode; its mean, standard deviation and RMS; and its crest factor,
skewness and excess kurtosis. They are taken over the channel's finite
samples only, and the panel says so on a channel that has NaNs or
infinities. A recording that carries its own timestamps is weighted by how
long each sample was held, so a burst of messages does not outweigh a long
steady stretch. On a large file the figures show as “…”
and fill in on their own, with the channel you are pointing at worked out
first.
A Notices panel beside it lists the channel's data-quality warnings with
their counts.
On a PSD plot the preview draws the channel's spectrum instead, on the same
engineering-unit or decibel axis as the main plot, and reads it in three
columns: the peak's frequency and level, with the roll-off above it; the
noise floor, the signal bandwidth and the dynamic range between them; and
how the spectrum was computed — Nfft, the number of averages, the
noise bandwidth, and the random error the averaging leaves behind.
A channel too slow for the PSD's bin spacing to resolve — a vehicle
speed, a steering angle — is flagged Not a vibration
channel, with the share of its variation sitting below that
resolution, rather than being given a peak that means nothing.
In the Time+PSD and Time+PSD+Histogram plots the preview shows both halves,
divided by a line: the time trace with its statistics, then the spectrum
across the full width with its own.
In the CSD plots the preview pairs the channel with every plotted channel
from its own file — its own spectrum first, then its cross spectrum
with each of them, following the main plot's decibel and phase-wrap
settings. A table underneath gives, for each pair, where the cross spectrum
peaks, its level and phase there, the coherence at that peak, and a band
coherence weighted so the frequencies where the two channels share power
are the ones that decide it.
The channel tooltip in the file tree is gone. Its range and quality
warnings are in the preview now, and its sample count is on the file's own
row.
PSD and CSD remove each segment's mean before the transform. A channel
riding an offset no longer shows a spike at 0 Hz taller than anything
it actually does, which used to set the scale for the whole plot.
Fixed: the phase in the CSD plots had the wrong sign for its labels, so the
matrix showed the opposite triangle from the one its labels named. A
channel that lags now reads negative.
0.28
Opening a file no longer freezes the window. A progress bar with the
file's name and a Cancel button appears in the plot area, and moving,
resizing and working with already-open files all keep working while a
large file loads.
Spectra, cross-spectra and histograms are computed in the background,
and are worked out for every channel as soon as a file finishes
loading. Switching to a PSD, CSD or histogram view is usually instant
as a result, where a ten-channel recording used to lock the window for
a minute or more.
Each open file's row in the tree has a close button. Closing a file
drops its plotted channels and renumbers the files after it; nothing
else needs re-selecting.
The window's position, size and maximized state are remembered between
runs, along with the splitter between the file tree and the plots.
Files can be dropped onto the window from Explorer, one or many at
once.
Spectra can be read in decibels — Plots → Spectra in
Decibels, or the dB button. It covers the PSD,
the CSD magnitude rows and the spectrum pane of the combined views, and
the choice is remembered between sessions.
CSV files no longer have to be tidy to open. The reader works out its
own delimiter and decimal separator, so a European export written as
1,5;2,5 reads correctly; it handles quoted fields, skips a
block of instrument metadata above the header, sets text columns aside
and fills cells it cannot read with NaN instead of refusing the file.
Space-separated text files open too.
Date and time stamps in a CSV are recognized: the plot starts at zero on
the first stamp, and the recording's absolute start time appears in the
file's details.
SimCreator .plt, RPC3 and fstrm files that are not exactly
to spec now open instead of being turned away — other writers'
header spellings and padding, mixed separators, comments and blank
lines, multi-rate rows. Short rows are padded with NaN, long rows cut to
the header's width, and whatever the reader had to fix is listed under
the file's details.
Recordings sampled at uneven intervals — event logs, CAN bus
traces — are drawn at the times their samples were actually taken,
in the plot and in the file tree's thumbnails alike. Their spectra are
computed against a real time grid, and their histograms weight each
sample by the time it stood for, so the shape describes the signal
rather than the logger's activity.
A corrupt or truncated file can no longer take the application down,
and a damaged file is reported in plain words — the line number
and what was missing — rather than as an internal error.
Stepping through channels with the toolbar's Increment and Decrement
buttons now scrolls the file tree to keep the plotted channel in
view.
Files load faster: about 16% for CSV and about 27% for SimCreator
.plt. Zoomed plots redraw faster as well.
The same program is available as PlotIt.exe for anyone
who knew it under its earlier name. It keeps its own settings, so an
existing PlotIt setup carries over untouched.
0.27
Renamed from PlotIt to EnginPlot (the old name collided with existing
tools).
Fixed a crash switching to the CSD matrix plot with no channels
selected.
A legend too big for the space it sits in is now cropped instead of
going blank — a single over-long channel name used to leave an
empty legend box, most visibly in the Time / PSD / Histogram view.
0.26
Fixed the harmonic-cursor suppression on frequency plots so it uses a
fixed pixel spacing instead of scaling with plot width — it was
tripping inconsistently depending on how wide the plot was.
0.25
Added a "Clear Recent Files List" item to the File menu.
0.24
CSV files no longer list a redundant straight-line time column as a
plottable channel.
0.23
Fixed the harmonic cursor on frequency plots (PSD/CSD) so it displays
correctly when zoomed in away from 0 Hz.
0.22
Middle-mouse-button panning now redraws the plot live while you drag,
instead of freezing until you let go.
0.21
Added data-quality indicators — NaNs, infinities, huge values,
subnormal values, and dead channels are now flagged directly on each
channel in the file tree, with a tooltip giving the full breakdown.
0.20
PlotIt now remembers recently opened files, and reopens to the folder
and file type you last used.
0.19
Added on-plot markers for NaN and infinite values, with a toggle to hide
them.
0.18
Refreshed the plot toolbar icons.
0.17
Added a legend visibility toggle.
Much faster rendering on large files.
Fixed numerous crashes on files containing NaN, infinity, or extreme
values.
0.16
Added Overlay, Stacked, and Stacked-by-Unit plot layouts.
0.15
Added a second Y-axis for channels on very different scales.
Various histogram and cursor fixes.
0.14 and earlier
Initial format support (RPC3, PLT, fstrm, CSV) and stability work.
