Advanced | SIMXSOM1

INTEGRAL MAXIMUM – [SIMXSOM1]
Computes the absolute maximum of an integral, a mean or a RMS value on a specific part of a signal and in a window moving.

CATEGORY
Advanced

DESCRIPTION
The function allows to compute the absolute maximum of an integral, a mean or a RMS value on a specific part of a signal and in a window moving over the input signal.

RESULT VARIABLES AND PARAMETERS

Algebraic Maximum	Maximum of the input signal, multiplied by the factor.
Absolute Maximum	Absolute maximum of the input signal, multiplied by the factor.
Signal	Input signal to perform analysis
Signal_Part	Part of the signal on which the analysis is done (neg, pos, sig, abs). Here are the definitions for the four distinct parts of a signal:
Neg	Only the negative values of the input signal are used for the calculations. The other values are considered to be null.
Pos	Only the positive values of the input signal are used for the calculations. The other values are considered to be null.
Sig	The original input signal is used for the calculations.
Abs	The calculations are done on the absolute value of the input signal.
Threshold	Threshold to reach in order to start analyzing the signals. This threshold value must be positive since the absolute value of the sample is compared to it. The samples which do not exceed this threshold are considered as null. If this threshold is null, all the samples are automatically considered.
Operation	Operation to execute on the signal in a window moving over it (int, moy, rms). The maximum of the integrals, means or RMS values are kept. int: integral, moy: mean, rms: rms value.
Window_Length	Time in seconds [s] during which the window moves over the analyzed signal. This time in seconds is reduced to the time of the analysis (end_time – begin_time), if the window time specified is longer than the duration considered for the signal. This window time cannot be null.
Begin_time	Time at which the analysis of a signal must start. This time is expressed in milliseconds [ms]. This value must be greater than 0 and lower than the size of the acquisition buffer. The default value is 0.
End_time	Time at which the analysis of a signal must end. This time is expressed in milliseconds [ms]. The value of this time must be larger than the specified begin_time and smaller than the duration of the test. Use the “HUGE” value to specify the end of the test. The default value is HUGE.
Factor	Multiplying factor for the results generated by the function. The default value of the multiplying factor is 1.0 and has no effect on the results.

SYNTAX
[alg_max, abs_max] = simxsom1( input, "sig", 0, "int", 1/60, 0, HUGE, 1 )

CHARACTERISTICS
Data type support
Double Floating point

EXAMPLE
In the following example, the function compute the absolute maximum of the integral of the sine wave over a moving window.

The following diagram shows the window moving over a signal based on the time specified for the window.

The operation is computed for each window from the start to the end of the limits and the function returns the computed samples.

Let:

nbech= number of samples to analyze for the signals
lfen= number of samples in a window
nbfen= number of windows for which the calculations are made

Then:

nbfen= nbech-lfen+1

This set of points is used to find the maximum.