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GeneralFIRE

GeneralFIR-E SOFA convention

Since R2023b

    Description

    The GeneralFIRE object stores SOFA data following the GeneralFIR-E convention. This convention is a general representation of data in emitter-dependent FIR filter form. It stores data for general purposes.

    Use sofaread and sofawrite to read and write SOFA files with this convention.

    Creation

    Create a GeneralFIRE object using sofaconvention.

    s = sofaconvention("GeneralFIRE");

    Properties

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    Data

    Impulse responses in FIR form, specified as a real-valued M-by-R-by-N-by-E array, where M is the number of measurements, R is the number of receivers, N is the impulse response length, and E is the number of emitters.

    Delay of each impulse response in samples, specified as a 1-by-R matrix, M-by-R matrix, or M-by-R-by-E array, where M is the number of measurements, R is the number of receivers, and E is the number of emitters.

    Sampling rate of the data in hertz, specified as a positive scalar.

    This property is read-only.

    Sampling rate units, returned as a string.

    This property is read-only.

    Type of data in the file, returned as a string.

    Listener

    Listener position in Cartesian or spherical coordinates, specified as a 1-by-3 or M-by-3 matrix, where M is the number of measurements.

    For more information, see Spatial Data Representations.

    Listener position type, specified as "cartesian" or "spherical".

    This property is read-only.

    Listener position units, returned as "meter" if ListenerPositionType is "cartesian" or "degree, degree, meter" if ListenerPositionType is "spherical".

    Listener view direction, specified as a 1-by-3 or M-by-3 matrix, where M is the number of measurements. This property defines the direction of the positive x-axis of the local listener coordinate system.

    Listener view type, specified as "cartesian" or "spherical".

    This property is read-only.

    Listener view units, returned as "meter" if ListenerViewType is "cartesian" or "degree, degree, meter" if ListenerViewType is "spherical".

    Listener up direction, specified as a 1-by-3 or M-by-3 matrix, where M is the number of measurements. This property defines the direction of the positive z-axis of the local listener coordinate system.

    Listener short name, specified as a string. This property defines the ID of the subject from the database.

    Listener description, specified as a string.

    Receiver

    Receiver positions in Cartesian coordinates, spherical coordinates, or spherical harmonics, specified as a 1-by-3 matrix, R-by-3 matrix, or R-by-3-by-M array, where M is the number of measurements. If ReceiverPositionType is "cartesian" or "spherical", R is the number of receivers. If ReceiverPositionType is "spherical harmonics", R is the number of spherical-harmonic coefficients.

    For more information, see Spatial Data Representations.

    Receiver position type, specified as "cartesian", "spherical", or "spherical harmonics".

    This property is read-only.

    Receiver position units, returned as "meter" if ReceiverPositionType is "cartesian" or "spherical harmonics". If ReceiverPositionType is "spherical", the units are returned as "degree, degree, meter".

    Receiver view direction, specified as an R-by-3 matrix or R-by-3-by-M array, where M is the number of measurements and R is the number of receivers. This property defines the direction of the positive x-axis of the local receiver coordinate system.

    Receiver view type, specified as "cartesian" or "spherical".

    This property is read-only.

    Receiver view units, returned as "meter" if ReceiverViewType is "cartesian" or "degree, degree, meter" if ReceiverViewType is "spherical".

    Receiver up direction, specified as an R-by-3 matrix or R-by-3-by-M array, where M is the number of measurements and R is the number of receivers. This property defines the direction of the positive z-axis of the local receiver coordinate system.

    Receiver short name, specified as a string.

    Receiver description, specified as a string.

    Source

    Source position in Cartesian or spherical coordinates, specified as a 1-by-3 or M-by-3 matrix, where M is the number of measurements.

    For more information, see Spatial Data Representations.

    Source position type, specified as "cartesian" or "spherical".

    This property is read-only.

    Receiver position units, returned as "meter" if SourcePositionType is "cartesian" or "degree, degree, meter" if SourcePositionType is "spherical".

    Source view direction, specified as a 1-by-3 or M-by-3 matrix, where M is the number of measurements. This property defines the direction of the positive x-axis of the local source coordinate system.

    Source view type, specified as "cartesian" or "spherical".

    This property is read-only.

    Source view units, returned as "meter" if SourceViewType is "cartesian" or "degree, degree, meter" if SourceViewType is "spherical".

    Source up direction, specified as a 1-by-3 or M-by-3 matrix, where M is the number of measurements. This property defines the direction of the positive z-axis of the local source coordinate system.

    Source short name, specified as a string.

    Source description, specified as a string.

    Emitter

    Emitter positions in Cartesian coordinates, spherical coordinates, or spherical harmonics, specified as a 1-by-3 matrix, E-by-3 matrix, or E-by-3-by-M array, where M is the number of measurements. If EmitterPositionType is "cartesian" or "spherical", E is the number of emitters. If EmitterPositionType is "spherical harmonics", E is the number of spherical-harmonic coefficients.

    For more information, see Spatial Data Representations.

    Emitter position type, specified as "cartesian", "spherical", or "spherical harmonics".

    This property is read-only.

    Emitter position units, returned as "meter" if EmitterPositionType is "cartesian" or "spherical harmonics". If EmitterPositionType is "spherical", the units are returned as "degree, degree, meter".

    Emitter view direction, specified as an E-by-3 matrix or E-by-3-by-M array, where M is the number of measurements and E is the number of emitters. This property defines the direction of the positive x-axis of the local emitter coordinate system.

    Emitter view type, specified as "cartesian" or "spherical".

    This property is read-only.

    Emitter view units, returned as "meter" if EmitterViewType is "cartesian" or "degree, degree, meter" if EmitterViewType is "spherical".

    Emitter up direction, specified as an E-by-3 matrix or E-by-3-by-M array, where M is the number of measurements and E is the number of emitters. This property defines the direction of the positive z-axis of the local emitter coordinate system.

    Emitter short name, specified as a string.

    Emitter description, specified as a string.

    Room

    Type of room used to perform the measurements, specified as a string.

    Metadata

    This property is read-only.

    Name of the SOFA convention, returned as a string.

    Name of the database that this data belongs to, specified as a string.

    This property is read-only.

    Version of the SOFA AES69 specifications, returned as a string of the format "x.y" where x is the version major and y is the version minor.

    This property is read-only.

    Name of the API that created or edited the SOFA file, returned as a string.

    This property is read-only.

    Version of the API that created or edited the SOFA file, returned as a string of the format "x.y" or "x.y.z" where x is the version major and y and z are the version minors.

    This property is read-only.

    Version of the SOFA AES69 convention set, returned as a string of the format "x.y" where x is the version major and y is the version minor.

    Title containing a succinct description of the file contents, specified as a string.

    Contact information of the author (for example, an email address), specified as a string.

    Name of the organization of the author, specified as a string.

    Legal license under which the data is provided, specified as a string.

    Name of the application that created or edited the file, specified as a string.

    Version of the application that created or edited the file, specified as a string.

    Comment that can contain miscellaneous information about the data or methods used to produce the data, specified as a string.

    History defining the audio trail for modifications to the original data, specified as a string.

    Published or web-based references that describe the data or the methods used to produce the data, specified as a string.

    Origin, specified as a string representing the method used for creating the original data. In the case of model-generated data, the origin should name the model and its version. In the case of observed or measured data, the origin should characterize the data and, where possible, name the measurement method.

    This property is read-only.

    Date and time of the creation of the file, returned as a string in ISO 8601 format "YYYY-MM-DD hh:mm:ss". This property is set when a new file is created.

    This property is read-only.

    Date and time of the last file modification, returned as a string in ISO 8601 format "YYYY-MM-DD hh:mm:ss". This property is updated when a file is saved.

    Object Functions

    writeWrite SOFA file
    validateValidate SOFA data

    Examples

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    Create a SOFA template object following the GeneralFIR-E convention for storing emitter-dependent impulse response measurements.

    s = sofaconvention("GeneralFIR-E");

    Generate mock impulse response data to store in the file. Initialize the Numerator property to store impulse responses of length 512 for 25 measurements, five emitters, and one receiver. Use the fir1 function to create random FIR filters for the impulse response measurements.

    M = 25;
    R = 1;
    N = 512;
    E = 5;
    s.Numerator = zeros(M,R,N,E);
    
    for m = 1:M
        for e = 1:E
            s.Numerator(m,1,:,e) = fir1(N-1,rand);
        end
    end

    Generate random spherical coordinates for each of the emitters.

    s.EmitterPositionType = "spherical";
    azimuth = 360*rand(E,1);
    elevation = -90 + 180*rand(E,1);
    radius = ones(E,1);
    
    s.EmitterPosition = [azimuth elevation radius];

    Save the data to a SOFA file.

    sofawrite("mockIRData.sofa",s);

    More About

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    Version History

    Introduced in R2023b