Peak Finder

The Peak Finder blocks accepts real-valued vector or matrix inputs with at least three rows.

Example: [9 6 10 3 5 5 0 12; 9 6 1 13 4 1 0 12]'

Number of peak values the block detects in the input signal, returned as a scalar or a row vector of length equal to the number of channels in the data input.

Example: [4 3]

Indices of the peak values in the input signal, returned as a column vector or matrix. The size of the peak indices output is the same as that of the input. All nonzero elements represent peak indices.

If you set Index base to Zero, the block outputs zero-based extrema indices. If you set Index base to One, the block outputs one-based extrema indices.

Example: [1 2 3 6 0 0 0 0 0 0; 2 3 6 0 0 0 0 0 0 0]'

Dependencies

To enable this output port, select the Output peak indices parameter.

Peak values in the input signal, returned as a column vector or matrix.

Example: [6 10 3 0 0 0 0 0 0 0; 1 13 0 0 0 0 0 0 0 0]'

Dependencies

To enable this output port, select the Output peak values parameter.

Peak value polarity in input signal, returned as a column vector or a matrix of logical 1s and 0s. If the signal value is a maximum, the block outputs 1 at this port. If the signal value is a minimum, the block outputs 0 at this port.

Example: [0 1 0 0 0 0 0 0 0 0; 0 1 0 0 0 0 0 0 0 0]'

Dependencies

To enable this port, select either Output peak indices or Output peak values, and set the Peak type(s) parameter to Maxima and Minima.

Specify the type of peaks to identify as one of these:

Specify the base of the extrema indices as either:

Select this check box if you want the block to output the extrema indices at the Idx port.

Select this parameter if you want the block to output the extrema values at the Val port.

Enter the number of extrema to look for in each input signal as an integer greater than or equal to 1. The block stops searching the input signal for extrema once the maximum number of extrema has been found.

Select this parameter if you want to eliminate the detection of peaks whose amplitudes are within a specified threshold of neighboring values. This feature allows the block to ignore noise by focusing on values above the specified threshold.

When you clear this parameter, the block identifies the current value as a peak if the current value is larger (or smaller) than both its neighboring points. When you select this parameter, the block identifies the current value as a maximum if (current – previous) > threshold and (current – next) > threshold. The block identifies the current value as a minimum if (current – previous) < –threshold and (current – next) < –threshold.

Specify the threshold below which peaks are ignored as a real scalar greater than or equal to 0 or a vector with all elements greater than or equal to 0. The length of the vector must be equal to the number of channels.

This property identifies the current input value to be a maximum if (current – previous) > threshold and (current – next) > threshold. The current value is a minimum if (current – previous) < –threshold and (current – next) < –threshold.

Dependencies

To enable this parameter, select the Ignore peaks within threshold of neighboring values parameter.

When you select this parameter, the block saturates the result of its fixed-point operations. When you clear this parameter, the block wraps the result of its fixed-point operations. For details on saturate and wrap, see overflow mode for fixed-point operations.

Dependencies

To enable this parameter, select the Ignore peaks within threshold of neighboring values parameter.