| File
name
|
AnHistogram.[ch]
|
| Description
|
This
routine generates a period histogram (PH) or a post stimulus time histogram
(PSTH) from the process EarObject's input signal. It puts the
result in the output signal, overwriting any previous data if the signal has
already been initialised. Accurate binning must be achieved, so real values
mut be used in determining the binWidth (s), bin widths. The histogram
is calculated from the first minimum after the specified offset (s) of
the input signal. There are several operating mode options. Not all of the
parameters are used for all modes, though they must always be present in the
parameter file when using ReadPars, i.e. In the "continuous" detection
mode, the eventThreshold parameter is not used.
Data will be accumulated until the process is resetsee section 0
Accumulating Data with Process Modules.
|
| Example
parameter file format
|
continuous Detection mode - spike (detection) or continuous (signal). PH Histogram type - PSTH or PH. 0.5 Event threshold for bin counts (units as appropriate). 0.01e-3 Bin width for the histogram (s). 1e-3 Period for period histogram (s). 0.0e-3 Offset for period histogram (s). |
| Test
program directory
|
Tests/Analysis
|
| Syntax
|
BOOLN Calc_Analysis_Histogram(EarObjectPtr
data);
|
| Returns
|
TRUE
if the process is successful, otherwise it returns FALSE.
|
| Syntax
|
BOOLN SetBinWidth_Analysis_Histogram(double
theBinWidth);
|
| Special
Values
|
A
negative bin width assumes a value the same as the input signal's sampling
interval
|
| Returns
|
TRUE
if the function is successful, otherwise it returns FALSE.
|
| Syntax
|
BOOLN SetDetectionMode_Analysis_Histogram(double
theDetectionMode);
|
| Special
Values
|
Mode
Options: "Continuous" signal or "spike" detection above eventThreshold
value.
|
| Returns
|
TRUE
if the function is successful, otherwise it returns FALSE.
|
| Syntax
|
BOOLN SetEventThreshold_Analysis_Histogram(double
theEventThreshold);
|
| Special
Values
|
(Not
used in "continuous" signal mode.)
|
| Returns
|
TRUE
if the function is successful, otherwise it returns FALSE.
|
| Syntax
|
BOOLN SetTimeOffset_Analysis_Histogram(double
theTimeOffset);
|
| Returns
|
TRUE
if the function is successful, otherwise it returns FALSE.
|
| Syntax
|
BOOLN SetPars_Analysis_Histogram(char
*detectionMode, char *typeMode, double eventThreshold,
double binWidth, double period, double timeOffset);
|
| Returns
|
TRUE
if the function is successful, otherwise it returns FALSE.
|
| Syntax
|
BOOLN SetPeriod_Analysis_Histogram(double
thePeriod);
|
| Special
Values
|
(Not
used in "PSTH" mode.)
|
| Returns
|
TRUE
if the function is successful, otherwise it returns FALSE.
|
| Syntax
|
BOOLN SetTypeMode_Analysis_Histogram(double
theTypeMode);
|
| Special
Values
|
Mode
Options: Post Stimulus Time Histogram "PSTH" or Period Histogram "PH".
|
| Returns
|
TRUE
if the function is successful, otherwise it returns FALSE.
|
# # Main Parameter file # output1.dat Name of output file. output2.dat Name of output file. output3.dat Name of output file. # # Module specifications. # #Par. file Name Description #--------- ----- ------------- PTone2.par PureTone Stimulus generation paradigm. Histogm1.par Histogram analysis parameter file. # Miscellaneous parameters 1 Number of repeated runs. 0.05e-3 Histogram bin width override (s). 2 Bin width adjustment scaler. 1000 Stimulus frequency (Hz). 2.0 Stimulus adjustment scaler.
Figure [38] Output 1 for PSTH histogram with the specified bin width.
Figure [39] Output 2 for PSTH histogram with the specified bin width scaled by a factor of two.
Figure [40] Output 3 for PSTH histogram with the specified frequency scaled
by two.
Comments:
In this test program the routine is used three times each with a pure tone stimulus: figure [38] tests the normal post stimulus time histogram: figure [39] repeats the previous test but with a larger bin width for the histogram; and figure [40] repeats the first test, but uses a stimulus with twice the frequency.
Figure [41] Output 1 for PH histogram with the specified bin width.
Figure [42] Output 2 for PH histogram with the specified bin width scaled by a factor of two.
Figure [43] Output 3 for PH histogram with the specified frequency scaled by
two.
Comments:
The period histograms shown above can be produced by changing the histogram mode in the "Histogm1.par" file from "PSTH" to "PH".
The period histogram , like the auto-correlation function, is used to investigate periodicity effects in signals. In constructing a period histogram the occurrence of each spike is summed into a histogram bin corresponding to time, but the time axis is reset for a constant period on the stimulus time scale.
In this test program the routine is used three times each with a pure tone stimulus: figure [41] tests the normal period histogram behaviour with a period width of one signal period (1/f): figure [42] repeats the previous test but with a smaller bin width for the histogram; and figure [43] repeats the first test, but uses a stimulus with twice the frequency. Thus the histogram period width is now twice the signal period.