ChannelWindow

Overview

ChannelWindow stores a sequence of MaxOne/Two data frames so they can be all be processed together, as opposed to examing individual frames. A ChannelWindow of length N is initialized with the first N frames of the experiment.

_images/window.png

Useful chip activity data can be extracted from the window, such as the firing rate and the average x-position of the spikes. For each new frame added to the window, the oldest frame is removed.

_images/window-change.png

If specified, the ChannelWindow will save the data for P number of past windows. Data is saved for each unique window, which means that none of the frames in the current window are in the most recently saved window.

For example, if the window is 200 frames long, then frames 0 through 199 are saved as the first past window. The next window that will be saved will contain frames 200 through 299, since that is the first set of frames where there is no overlap with the most recently saved window.

Similar to how ChannelWindow handles frames, when there are P past windows and a new window is saved, the oldest window will be removed.

Currently, the only window data that is saved is the firing rate, but this can easily be extended.

Example:

Step-by-Step

This example assumes that P = 2, meaning that up to 2 past windows will be saved. The first instance of the window is unique, so its firing rate is saved.

_images/past1.png

The window progresses.

_images/past2.png

As soon as the window does not overlap with the most recently saved window, its firing rate is saved.

_images/past3.png

The window progresses.

_images/past4.png

If there are P (2 in this case) past windows, then the oldest one is removed whenever a new one is saved.

_images/past5.png

_images/past-windows.gif

ChannelWindow uses ElectrodeMap to filter out any unwanted frames; this behaviour is particularly helpful if there are multiple windows in an experiment, where each window represents a different part of the chip.

Members

class ChannelWindow

Add description for the ChannelWindow class

Public Functions

ChannelWindow(int length, const char *configPath, int toSave = 0)

Constructor.

Creates a new ChannelWindow object

Parameters:

  • length – int representing the length of the window (measured in frames)

  • configPath – char array representing the full path of the config to use for the underlying ElectrodeMap

  • toSave – int indicating how many past window firing rates are to be saved, default=0

ChannelWindow(int length, ElectrodeMap emap, int toSave = 0)

Constructor.

Creates a new ChannelWindow object

Parameters:

  • length – int representing the length of the window (measured in frames)

  • emap – ElectrodeMap holding the current electrode config file

  • toSave – int indicating how many past window firing rates are to be saved, default=0

void init()

Initialize the window.

This will read in maxlab::FilteredFrameData structs until the window is full. The data streamer must be initialized before calling this function.

void shift(maxlab::FilteredFrameData frame)

Shifts window, appending new data frame to the end.

Shifts the window by removing the first frame, updating the total sum accordingly, and adding the new frame to the end. Similar to add, the sum will only be incremented for each channel in frame that exists in the electrode map. Note that it will only count the maxlab::spikeEvents that are found in the given config.

If the window has no been initialized, this function will simply add the frame to the end of the window.

Parameters:

frame – maxlab::FilteredFrameData struct to add to the window

maxlab::FilteredFrameData get(int idx)

Gets a maxlab::FilteredFrameData struct at the specified index.

Parameters:

idx – int representing the index of the target frame

Returns:

maxlab::FilteredFrameData struct at the specified index within the window

int length()

Returns the length of the window.

Returns:

int

int totalSpikeCount()

Returns the sum of all the spike counts (of valid channels) in the window.

Returns:

int

int numChannels()

Returns the number of channels that the window tracks.

Returns:

int

ElectrodeMap electrodeMap()

Returns the ElectrodeMap

Returns:

ElectrodeMap containing all of the channel, electrode mappings

float avgPastWindows()

Gets a vectors containing the firing rates of all the past windows.

Returns the average firing rate of all the past windows

Returns:

vector<float>

Returns:

float

float getAvgX()

Computes the average x coordinate of all the spike events in the window, counting each channel only once.

Returns:

float

float firingRateSD()

Computes the standard deviation of the firing rates of all past windows.

Returns:

float

float firingRate()

Computes the firing rate of the window.

Returns:

float

bool pastWindowsReady()

Indicates whether the window is completely unique from the past windows.

The past windows are stored end-to-end, so, at any point in time, there is a high chance that the current window overlaps with the past ones. When this function returns true, the current window does not overlap with any of the previous windows, and will be counted in all computations relating to the past windows.

Returns:

bool

void print()

Prints the ChannelWindow.

void debug(string message)

Prints the window with a message.

Also counts each spike event in the window manually, and compares it to the recorded sum

Parameters:

message – string to print