extractsigroi

R2026b

Extract regions of interest based on signal mask

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Syntax

sigroi = extractsigroi(msk,x)
sigroi = extractsigroi(msk,x,Name=Value)
[sigroi,limits] = extractsigroi(___)
[sigroi,limits,numroi,cats] = extractsigroi(___)

Description

sigroi = extractsigroi(msk,x) extracts regions of interest of the input signal vector x based on the source and properties in msk.

example

sigroi = extractsigroi(msk,x,Name=Value) specifies additional options using name-value arguments. You can choose to concatenate extracted regions and select the number of regions to extract per category.

example

[sigroi,limits] = extractsigroi(___) returns an array with the locations of the extracted region endpoints.

[sigroi,limits,numroi,cats] = extractsigroi(___) also returns numroi, a vector containing the number of regions found for each of the categories listed in cats.

Examples

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Open Live Script

Consider a region-of-interest (ROI) table with three regions labeled A and two regions labeled B. Use the table to create a signalMask object. 

roiTbl = table([2 5; 7 10; 12 13; 15 25; 28 30],["A","B","A","B","A"]');

m = signalMask(roiTbl);

Generate an array with prime numbers smaller than 150. Use the signalMask object to extract the primes specified in the ROI table. Display the first set of A primes and the first set of B primes.

prm = primes(150);

rgs = extractsigroi(m,prm);

AB = [rgs{1}{1} rgs{2}{1}]
AB = 4×2

     3    17
     5    19
     7    23
    11    29

Repeat the operation, but now concatenate the regions of interest for each category. Display the first six A primes and the last six B primes.

rgs = extractsigroi(m,prm,ConcatenateRegions=true);

AB = [rgs{1}(1:6) rgs{2}(end-5:end)]
AB = 6×2

     3    71
     5    73
     7    79
    11    83
    37    89
    41    97

Repeat the operation, but now ignore regions with two samples or less. Display the first six A primes and the last six B primes.

m.MinLength = 3;

rgs = extractsigroi(m,prm,ConcatenateRegions=true);

AB = [rgs{1}(1:6) rgs{2}(end-5:end)]
AB = 6×2

     3    71
     5    73
     7    79
    11    83
   107    89
   109    97

Input Arguments

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Signal mask, specified as a signalMask object.

Example: signalMask(table([2 4;6 7],["male" "female"]')) specifies a signal mask with a three-sample male region and a two-sample female region.

Example: signalMask(categorical(["" "male" "male" "male" "" "female" "female" ""]',["male" "female"])) specifies a signal mask with a three-sample male region and a two-sample female region.

Example: signalMask([0 1 1 1 0 0 0 0;0 0 0 0 0 1 1 0]',Categories=["male" "female"]) specifies a signal mask with a three-sample male region and a two-sample female region.

Input signal, specified as a vector.

Example: chirp(0:1/1e3:1,25,1,50) specifies a chirp sampled at 1 kHz.

Data Types: single | double
Complex Number Support: Yes

Name-Value Arguments

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Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Example: ConcatenateRegions=true,SelectedRegions=[2 4] specifies that the function extract the second and fourth regions of each category and concatenate them.

Option to concatenate extracted signal regions, specified as a logical value.

  • If this argument is set to false, then each cell of sigroi is a cell array corresponding to an individual signal region.

  • If this argument is set to true, then each cell of sigroi is a vector of concatenated extracted signal regions for each category contained in msk.

Data Types: logical

Regions selected for extraction, specified as a vector of integers.

  • If this argument is set to 1, then extractsigroi extracts only the first region of each category and returns it in sigroi.

  • If this argument is set to [i j k ...], then extractsigroi extracts the ith, jth, kth, and successive regions of each category and returns them in sigroi.

The function ignores indices larger than the number of regions present for a given category.

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64

Output Arguments

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Signal regions of interest, returned as a cell array. Each cell of sigroi contains a cell array with the signal regions extracted for each category in msk.

  • If ConcatenateRegions is set to false, then each cell of sigroi is a cell array corresponding to an individual signal region.

  • If ConcatenateRegions is set to true, then each cell of sigroi is a vector of concatenated extracted signal regions for each category contained in msk.

Extracted region limits, returned as a cell array of two-column matrices. If msk specifies a SampleRate, the region limits are expressed in seconds. If msk does not specify a sample rate, the region limits are integers corresponding to signal sample indices.

Number of regions found for each of the categories in cats, returned as a vector of integers.

Category list, returned as a vector of strings.

Version History

Introduced in R2020b

See Also

Apps

Objects

Topics