The "Plot from Quicklist" function provides the ultimate flexibility in plotting
and analysis tools. Three plotting modes are supported:
Separate Plots
Overlay Plot Time
Overlay Plot Frequency
The plot setup above shows configuration of a Separate plot. In
a Separate plot, up to four traces are plotted independently of one another
(see picture below), with separate axes. Each trace can have different data
types:
Time (Time Series),
Fourier (Frequency Spectrum),
Integrated Fourier,
Auto Correlation,
Cross Correlation.
The x and y-axis can be plotted in linear or logarthmic scales independently.
Two statistics are displayed with each plot --your choice of:
Mean
Standard Deviation (1 Sigma)
% Standard Deviation
2 Sigma
% 2 Sigma
3 Sigma
% 3 Sigma
Variance
Median
Range
% Range
RMS
AC Level Estimate
DC Level Estimate
Maximum
Minimum
There are many ways to present Fourier (frequency spectrum) plots. Most
programs force the user to become accustomed to one particular format
best suited for one particular application or field of study. Analyse-Plus
doesn't. In the lower right corner of the above display, you can choose
what type of windowing to use (Hamming, Blackman, etc.), whether to scale
the intensity (y-axis) as power or amplitude, whether to display the intensity
as vertical lines or to connect the individual points and whether to scale
the x-axis in terms of frequency or period. Regardless of this latter selection,
you can still scale the x or y axis in linear or log format and, if you
selected "frequency", you can have the x-axis labelled in terms of period
or frequency. This flexibility satisfies virtually every application, field
of study and personal taste.
Click on one of the QL
buttons and the QuickList appears as pictured below:
The Quick List holds up to 300 of the last data files used. Files that you have
opened from your hard disk appear at the top. Any files you have modified
with the Edit or Math functions are automatically moved to the top for quick
access. The field at the right indicates which modified files have not been
saved. As new files are created from a collection by the DataLogger, they are
inserted just below the barrier "Recently Collected Data Files". This design
ensures that modified (unsaved) files stay in the Quick List at the top where
they're handy to find yet collected data can be found quickly for plotting,
analysis, editing etc.
This example of a Separate Plot has 1 Time plot followed by 2 Fourier
(Frequency Spectrum) plots and 1 Cross-Correlation plot. In general, up
to 4 plots can be chosen with the same or different files with the same
or different data types.
The Time graph shows a Former (like a Headbox) Pressure on a paper
machine. This data was collected using the Data Logger CVF2 sampling at
1 msec intervals (1000 samples/sec).
Clearly the pressure is cycling. The Fourier plot (2nd from top) shows
the main frequencies. In this case, the x-axis scale is linear with respect
to frequency (as is conventional) but the user has clicked the "Period"/"Frequency"
button at the base of the window so that the x-axis labels are in terms
of preiod (sec). The user has also zoomed in on one region from 1 to 0.08
sec in period.
The 3rd plot shows Basis Weight (weight of the paper for
a given area) on the same paper machine. Clearly, the main frequencies
in the Pressure are also present in the Basis Weight, confirming that this
pressure variation is affecting the quality of the sheet. The user has also
enabled the cursors and can determine the value of any specific point on
the screen. This is useful to confirm that the frequencies are
exactly identical and that the other frequencies present in
Basis Weight are actually harmonics (exact multiples of the base frequency)
and are therefore also caused by the same pressure cycle.
The 4th plot shows a cross-correlation of Headbox Inlet Pressure to Dry
Weight at another paper mill.
There was no obvious visual correlation between the Pressure and Dry Weight
Time Series.
But the cross-correlation plot shows that there is a correlation of almost 0.5 -- quite high considering
the noise and short-term variation present in the signal. The plot shows
that the correlation occurs at a lag (delay) of 57 seconds. Since the
transport lag on the paper machine was known to be about 55 to 59 seconds
at this speed, Analyse-Plus has shown that the headbox pressure variation
is likely causing the dry weight variation. These examples show how Analyse-Plus
provides tangible & valuable benefits.
The tag, description, status, units, date & time of collection and 2 statistics
are displayed for each tag. You can display the statistics for the entire
data set ("Extents") or for the zoomed region ("Region") to allow comparison
of variability.
The graph is normally automatically scaled -- you can directly enter
values on the y and x axes for manual scaling.
The pallette to the right of each graph allows resetting of x and y axes
(to automatic scales), to grab the trace and slide it, zoom in, zoom
out or changing the axes from/to log or linear scaling. The zoom
function pictured at right, allows zooming in the y direction ,the x direction, x and y, or with
respect to a specific point (6 zoom methods). All
plots are zoomed and scaled independently.
The Cursor button in the lower right corner of the window makes cursors
appear in each plot. Use the + icon in the pallette to move the cursor to
a specific location or the diamond-shaped pallette to click the cursor one
sample at a time. The corresponding x-axis value (time, frequency etc) and
y-axis value (measured sample in Engineering units, or amplitude/power, etc.)
is displayed. This means you can zoom in on any area and see specific data
values.
The Frequency button toggles between period and frequency labels on the
x-axis of frequency plots. In the above example, period labels are shown.
You can manual scale the x-axis by entering period or frequency values.
Click the Print button to get a color or B&W hardcopy or to capture a
"clean-screen" (see below). Click the Color
Settings button beforehand if you need to adjust the colors. Click the
Copy button to copy the plot data to the clipboard (see below).
This application cooperates with the DataLogger to pass printouts through
the print-thru port to the printer. This can even be done during a data
collection if in Stand-Alone mode. When you are
not using the
DataLogger, you can connect the printer directly to the computer and print
normally. You could alternatively print through a USB port or network.
While not communicating with the DataLogger, a Print-Thru ("PT") LED
on the DataLogger is on. If you intend to collect data after printing through
the parallel port,
click the "Connect" button on the Main window.
This resumes communication
(PT LED turns off). If the DataLogger had been performing a collection,
its samples would be recorded in its own memory (in Stand-Alone mode).
Normally there would be no loss of data. Data is saved to your hard
drive after reconnection.
The plot setup screen pictured above is identical to the one at the top
of this page except that the "Overlay-Time" plot type has been selected.
Now, up to 10 variables can be plotted. The % Overlay setting near the
bottom allows you to specify how much each trace overlaps the ones below
and above. The Span/Zero/Overlay check boxes allow you to specify overides
for each trace. For example, you could set the span in engineering units of
several traces to be equal to allow visual comparison. In the example plot
below, that corresponds to the plot setup above, the D0 Stage Consistency setpoint
and measurement have these overrides set so that they occupy the same
physical place on the plot. The D0 Level setpoint and measurement are set
the same way. This relationship will be maintained wihle zooming or dragging
the traces, etc.
In an Overlay Time plot (above), all data files selected are plotted
against the same time scale even if the sample periods are different.
The tag, description, status, units,
date & time of collection and 2 statistics
(see Plotting and Analysis above) are displayed
for the first 5 files plotted. Click on the "Plots 6-10" button to toggle
to show the same information for the other 5 traces. The degree of overlap of the traces was
chosen by in the plot setup window as 50 %.
Click on the radio buttons to choose to display the statistics for the entire
data set ("Extents") or for the zoomed region ("Region") to allow comparison
of variability.
The graph is normally automatically scaled -- you can enter manual scale
values directly on the x or y axes.
The pallette to the right of each plot allows resetting of x and y axes
(to automatic scales), to grab the trace and slide it, zoom in, zoom out,
changing the axes from/to log or linear scaling or to rebalance the
overlap of the traces. The zoom
function allows zooming in the y direction, the x direction, x and y, or with
respect to a specific point.
Click the "Cursor/No Cursor" button in the lower right corner of the window
to turn on or off the cursor. The cursor is shown in the above plot as a
light blue cross-hairs. Use the + icon in the pallette to move the cursor to
a specific location or the diamond-shaped pallette to click the cursor one
sample at a time. The corresponding time value and measured sample in
Engineering units is displayed below the pallette. This means you can zoom
in on any area and
see specific data values. The cursor can be moved to another trace by
clicking the colored radio buttons to the right of the legend or by clicking
on the upper & lower portions of the cursor diamond.
Click the Color
Settings button if you need to adjust the colors. The colors of
all traces, the display and plot backgrounds, and the cursor color are
all adjustable to allow you to get the perfect presentation of your data.
Click the Print button to get a color or B&W hardcopy or to save the graphic
image of a "clean-screen". The Print window is shown below.
Enter a title, then select the "Print" radio button to print. If you wish
to export the graphic image of a clean-screen plot, choose your favourite
file format (PNG, BMP, JPEG, or the clipboard). PNG is very highly recommended
for emailing, importing into word-processors or web pages etc. or merely
archiving. The image below is the actual PNG file image for the plot above.
Most importantly, the legend and stats for all 10 traces are now displayed.
The printed plot appears exactly the same as this. Note that
this PNG file is only 23 KB long.
If you've ever printed color plot displays on a standard black & white printer
with your favourite spreadsheet application, you know that some traces
completely disappear in the color translation or are indistinguishable from
other traces. We have a solution for this. Setup the
corresponding thickness and style of the black & white
lines for each trace just once.
The setup will be saved and reused every print.
To do this, click on the B & W Print Setup button in the Print window
(2 windows above). Ten distinguishable B & W
trace settings have already been chosen as defaults for most laser and inkjet
printers and for screen captures. You can also choose custom settings from 60
line types. "A Test Print"
button prints all available types to verify how they look on your printer.
After the one-time setup, click the
B & W Print button for a standard black on white printout.
Click on the "Copy" button to copy the data from any plot to the clipboard
as text. The window pictured below will be displayed.
The above plot is an Overlay Frequency plot. All data files selected are plotted
against the same frequency scale. This plot includes the same tools as the
Overlay Time plot. Like the Separate plot, the x-axis labels can be
switched from frequency to period labels with a single click. In the above
case, the x-axis has a Linear Frequency scale with period labels.
The Overlay Frequency plot is very useful for overlaying a Fourier spectrum
on a Integrated Fourier spectrum (as in the example above). Together, you
can estimate the percentage of the variability caused by a particular cycle.
Many Math Functions are available to help you analyse your
data. See Math Functions & Channels.