What is baudline?
Mystery Signal
The average window is a way of collecting and displaying accumulated spectral traces.  Averaging over time reduces the random noise element which can bring out the detail of steady state stationary signals.  To open the average window select the average option in the displays sub section of the main window. 

Click the thumbnail below for a larger image.

The popup menu on the right is accessed by holding down the third mouse button while the mouse cursor is in the average window.  Through this menu the modes of collection, clearing, and display can be controlled.

There are two ways to collect average spectrum traces.  The first is in the record mode.  You manually choose Start or hit the space key to begin, data is collected for a period of time, then you choose Stop or hit the space key.  The second way is in the pause mode.  Like in the histogram window, a block of data is selected in the spectrogram or waveform window, if no data is selected then the entire data buffer is used, next the Paste menu button or the second mouse button is pressed while in the average window.  A wait cursor will popup while the average spectrum is calculated.  Note that the average window can collect data when it is either open or iconified; when it is closed, spectrum collection is turned off.

The average spectrum can be set to exponentially decay with a user specified duration while in the record mode.  This option changes the default infinite spectral accumulation behavior to a more responsive real-time mode of operation.  Note that this decay option does not function in the pause mode where the standard paste and accumulate functionality still operates.

Select a timer function that acts every duration time slice while in the record mode.  The off option does nothing.  The stop option will halt average collection after the timer duration limit has expired.  The clear option will periodically clear the spectral trace.  The shift bank option will increment the average destination bank every duration time slice and halt collection when the last bank is complete.  The rotate bank option is identical the shift bank option but instead of halting collection the last bank rotates to the first bank (F1) for an infinite bank rotation.  The last bank menu selects the final F#(1 - 12) bank that is used by both the shift bank and the rotate bank settings. 

For example; selecting the rotate bank option with a last bank of F2 will ping pong between the average F1 and F2 banks forever with a switch time controlled by the duration menu.  Note that the timer function can operate in conjunction with the decay option for combined functionality.

Select a decay or timer duration value between 25 ms and 24 hours.  The decay, timer, or auto save options need to be selected for the duration menu to be active.

open file
This is used to import spectral data.  Load a single file or a set of files (.1 - .12 suffixes) from disk to the average memory banks.  The file format is the same as is used in the equalization window.  The format is two column (Hz, dB) ASCII text which can be plotted with xgraph or gnuplot.

save file as ...
This is used to export spectral data to a two column (Hz, dB) ASCII text file.  Save any or all (.1 - .12 suffixes) of the average memory banks to disk.  Saved average data files can be opened with the above open file command.

auto save
The average auto save feature generates time stamped text files at a rate controlled by the timer duration setting.  Durations of less than 10 seconds are not allowed.  Use this option with caution to avoid filling the storage device.  The current channel selection is automatically saved to a UTC time stamped file name with the same text data format that is used by the save file as ... option.  Using this option with the decay or the clear timer option may be a useful combination.

Perform a clear operation on either the current trace as defined by the destination menu or on All twelve of the average memory traces.  The auto clear option controls if the current trace is cleared before new data is added to it such as when a paste action, a start action, or a destination bank change while collecting is performed.  When auto clear is turned off the started or pasted selection will just add to the average spectrum that is currently there. 

The average window is monophonic in that it only operates on a single channel at a time.  To average the spectrum of some other channel, first make sure it is ON in the input channel mapping window, and then select the appropriate channel position in this menu.

This is the memory trace to use for the next average spectrum collection.  Like all of the menus in baudline this menu can be torn off for quick access and to be a visual legend.  Or the function keys (F1 - F12) can be used to change trace destinations.  If auto clear is on then a memory trace is cleared each time it is selected.

This is used to display or hide a specific trace (F1 -F12). This menu is similar in appearance to the destination menu.  The short cut key is Alt+F# and it acts as a toggle on/off.

Hz scaling
This is used to zoom the Hz axis in or out with a zoom factor from 1X to 64X.  The minimum zoom factor is 1X which gives the most detail; it also happens to be the default value.  Zooming out gives a birds eye view, and after a certain point the window width shrinks.  This type of zooming on the Hz axis is also know as reduction scaling.  See the spectrogram and spectrum window's description of the Hz scaling reduction menu.  Note that the min max pair option is not available with the Average window.

dB scaling
This is used to zoom the dB axis in or out with a zoom factor from 1X to 128X.  Alt+Up zooms in and Alt+Down zooms out.

title bar
The destination trace bank number and the dB scaling factor are shown.

Like the ruler in the spectrum window the horizontal axis on the top ruler is frequency.  The vertical axis on the left ruler is spectral energy in decibels (dB).  At the top is the 0 dB reference point which is defined to be the loudest level possible from the input source (16 bits).  At the bottom of the ruler is -136 dB which means 136 dB beneath the 0 dB reference signal.  Because this axis is zoomable the ruler will change to reflect the current upper and lower limits.

This is the summed and averaged frequency spectrums with different trace banks being different colors.

The on screen display (OSD) in the upper right corner of the spectrum window displays the frequency or dB value that the mouse is currently pointing at.  This is useful for pinpointing measurements. 

scroll bars
The frequency scroll bar is on the bottom and the dB energy scroll bar is on the right.  They allow moving the average view port around. Note that the mouse scroll wheel is attached to the dB scroll bar.  The Alt+wheel and Alt+Shift+wheel zoom the dB and frequency axes respectively.  The arrow keys navigate and the Alt+arrow keys zoom as is the expected behavior.  The page up and page down keys navigate dB axis up and down a full screen's worth at a time  See the keyboard reference tables for all of the hotkey shortcuts.

harmonic helper bars
When the harmonic helper bars are activated in the spectrum or spectrogram windows they also pop up and track in the average window.  This way the user can check for harmonic relationships between the two windows at the same time.

delta measurement bars
The average delta measurement bars use the same click, hold, shift, drag, and release sequence that they do in the spectrum window.  Here are the steps:
  1. Click and hold the 1st mouse button in the spectrum window and the crosshairs will appear (see the illustration below).
  2. Move the mouse until the crosshairs are positioned to your measurement starting location.
  3. Press the Shift key and drag the mouse.  The delta measurement box will appear and the delta text will display the frequency and dB difference from the starting point to the end point.  Accurate measurements can be made this way. 
  4. Release the 1st mouse button to make the measurement box and text disappear. 
The delta selected and the frequency range display higher precision delta measurement values for future reference.  See the illustration below for a graphical example of the click, hold, shift, drag, and release operation.

click and hold

shift and drag

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