dn_apod_func

Apodization Function Definitions

The following defines the apodization functions used in the INFOS software. These are setup to match the definitions used by Bruker Topspin. For each dimension, X, the variable ‘t’ runs from 0 to ‘dX.AQ’, with ‘dX.TD’ points in between. The type of apodization function is specified in the ‘par.dX.WDW’ or ‘spec.par.dX.WDW’ field, using an index or a string, which are given below, along with the function definition. The other parameters (LB, GB, AQ, etc.) are also provided in either ‘par.dX’ or ‘spec.par.dX’.

No Apodization:

    dX.WDW=0||dx.WDW=’no’
    apod=ones(1,numel(t));

Exponential:

    dX.WDW=1||dX.WDW=’em’
    apod=exp(-pi*LB*t);

Gaussian:

    dX.WDW=2||dX.WDW=’gm’
    apod=exp(-pi*LB*t+(pi*LB*t.^2)/(2*GB*AQ));

Sine:

    dX.WDW=3||dX.WDW=’sine’
    if SSB>=2
        apod=sin(pi*(1-1/SSB)*t/AQ+pi/SSB);
    else
        apod=sin(pi*t/AQ)
    end

Squared Sine:

    dX.WDW=4||dX.WDW=’qsine’
    if SSB>=2
        apod=sin(pi*(1-1/SSB)*t/AQ+pi/SSB).^2;
    else
        apod=sin(pi*t/AQ).^2;
    end

Sinc:

    dX.WDW=7||dX.WDW=’sinc’
    apod=sin(2*pi*SSB*(t/AQ-GB));

Squared Sinc:

    dX.WDW=8; dX=WDW=’qsinc’;
    apod=sin(2*pi*SSB*(t/AQ-GB));

User defined:

    dX.WDW=’user’;
    apod=dX.apod;

Note that dX.apod must have the correct length, based on the acquisition time and sweep width of the dimension