fitlinesc

PURPOSE ^

fits significant sine waves to data (continuous data).

SYNOPSIS ^

function [datafit,Amps,freqs,Fval,sig]=fitlinesc(data,params,p,plt,f0)

DESCRIPTION ^

 fits significant sine waves to data (continuous data).

 Usage: [datafit,Amps,freqs,Fval,sig]=fitlinesc(data,params,p,plt,f0)

  Inputs:  
 Note that units of Fs, fpass have to be consistent.
       data        (data in [N,C] i.e. time x channels/trials or a single
       vector) - required.
       params      structure containing parameters - params has the
       following fields: tapers, Fs, fpass, pad
           tapers : precalculated tapers from dpss or in the one of the following
                    forms: 
                   (1) A numeric vector [TW K] where TW is the
                       time-bandwidth product and K is the number of
                       tapers to be used (less than or equal to
                       2TW-1). 
                   (2) A numeric vector [W T p] where W is the
                       bandwidth, T is the duration of the data and p 
                       is an integer such that 2TW-p tapers are used. In
                       this form there is no default i.e. to specify
                       the bandwidth, you have to specify T and p as
                       well. Note that the units of W and T have to be
                       consistent: if W is in Hz, T must be in seconds
                       and vice versa. Note that these units must also
                       be consistent with the units of params.Fs: W can
                       be in Hz if and only if params.Fs is in Hz.
                       The default is to use form 1 with TW=3 and K=5

            Fs             (sampling frequency) -- optional. Defaults to 1.
               fpass       (frequency band to be used in the calculation in the form
                                   [fmin fmax])- optional. 
                                   Default all frequencies between 0 and Fs/2
            pad            (padding factor for the FFT) - optional (can take values -1,0,1,2...). 
                    -1 corresponds to no padding, 0 corresponds to padding
                    to the next highest power of 2 etc.
                       e.g. For N = 500, if PAD = -1, we do not pad; if PAD = 0, we pad the FFT
                       to 512 points, if pad=1, we pad to 1024 points etc.
                       Defaults to 0.
        p            (P-value to calculate error bars for) - optional. 
                           Defaults to 0.05/N where N is data length.
       plt         (y/n for plot and no plot respectively) - plots the
       Fratio at all frequencies if y
       f0          frequencies at which you want to remove the
                   lines - if unspecified the program
                   will compute the significant lines


  Outputs: 
       datafit        (linear superposition of fitted sine waves)
       Amps           (amplitudes at significant frequencies)
       freqs          (significant frequencies)
       Fval           (Fstatistic at all frequencies)
       sig            (significance level for F distribution p value of p)

CROSS-REFERENCE INFORMATION ^

This function calls: This function is called by:

SOURCE CODE ^

0001 function [datafit,Amps,freqs,Fval,sig]=fitlinesc(data,params,p,plt,f0)
0002 % fits significant sine waves to data (continuous data).
0003 %
0004 % Usage: [datafit,Amps,freqs,Fval,sig]=fitlinesc(data,params,p,plt,f0)
0005 %
0006 %  Inputs:
0007 % Note that units of Fs, fpass have to be consistent.
0008 %       data        (data in [N,C] i.e. time x channels/trials or a single
0009 %       vector) - required.
0010 %       params      structure containing parameters - params has the
0011 %       following fields: tapers, Fs, fpass, pad
0012 %           tapers : precalculated tapers from dpss or in the one of the following
0013 %                    forms:
0014 %                   (1) A numeric vector [TW K] where TW is the
0015 %                       time-bandwidth product and K is the number of
0016 %                       tapers to be used (less than or equal to
0017 %                       2TW-1).
0018 %                   (2) A numeric vector [W T p] where W is the
0019 %                       bandwidth, T is the duration of the data and p
0020 %                       is an integer such that 2TW-p tapers are used. In
0021 %                       this form there is no default i.e. to specify
0022 %                       the bandwidth, you have to specify T and p as
0023 %                       well. Note that the units of W and T have to be
0024 %                       consistent: if W is in Hz, T must be in seconds
0025 %                       and vice versa. Note that these units must also
0026 %                       be consistent with the units of params.Fs: W can
0027 %                       be in Hz if and only if params.Fs is in Hz.
0028 %                       The default is to use form 1 with TW=3 and K=5
0029 %
0030 %            Fs             (sampling frequency) -- optional. Defaults to 1.
0031 %               fpass       (frequency band to be used in the calculation in the form
0032 %                                   [fmin fmax])- optional.
0033 %                                   Default all frequencies between 0 and Fs/2
0034 %            pad            (padding factor for the FFT) - optional (can take values -1,0,1,2...).
0035 %                    -1 corresponds to no padding, 0 corresponds to padding
0036 %                    to the next highest power of 2 etc.
0037 %                       e.g. For N = 500, if PAD = -1, we do not pad; if PAD = 0, we pad the FFT
0038 %                       to 512 points, if pad=1, we pad to 1024 points etc.
0039 %                       Defaults to 0.
0040 %        p            (P-value to calculate error bars for) - optional.
0041 %                           Defaults to 0.05/N where N is data length.
0042 %       plt         (y/n for plot and no plot respectively) - plots the
0043 %       Fratio at all frequencies if y
0044 %       f0          frequencies at which you want to remove the
0045 %                   lines - if unspecified the program
0046 %                   will compute the significant lines
0047 %
0048 %
0049 %  Outputs:
0050 %       datafit        (linear superposition of fitted sine waves)
0051 %       Amps           (amplitudes at significant frequencies)
0052 %       freqs          (significant frequencies)
0053 %       Fval           (Fstatistic at all frequencies)
0054 %       sig            (significance level for F distribution p value of p)
0055 data=change_row_to_column(data);
0056 [N,C]=size(data);
0057 if nargin < 2 || isempty(params); params=[]; end;
0058 [tapers,pad,Fs,fpass,err,trialave,params]=getparams(params); 
0059 clear pad fpass err trialave;
0060 if nargin < 3 || isempty(p);p=0.05/N;end;
0061 if nargin < 4 || isempty(plt); plt='n'; end;
0062 if nargin < 5; f0=[]; end;
0063 params.tapers=dpsschk(tapers,N,Fs); % calculate the tapers
0064 [Fval,A,f,sig] = ftestc(data,params,p,plt);
0065 if isempty(f0);
0066    fmax=findpeaks(Fval,sig);
0067    freqs=cell(1,C);
0068    Amps=cell(1,C);
0069    datafit=data;
0070    for ch=1:C;
0071        fsig=f(fmax(ch).loc);
0072        freqs{ch}=fsig;
0073        Amps{ch}=A(fmax(ch).loc,ch);
0074        Nf=length(fsig);
0075 %       fprintf('The significant lines for channel %d and the amplitudes are \n',ch);
0076 %        for nf=1:Nf;
0077 %            fprintf('%12.8f\n',fsig(nf));
0078 %            fprintf('%12.8f\n',real(A(fmax(ch).loc(nf),ch)));
0079 %            fprintf('%12.8f\n',imag(A(fmax(ch).loc(nf),ch)));
0080 %            fprintf('\n');
0081 %        end;
0082        datafit(:,ch)=exp(i*2*pi*(0:N-1)'*fsig/Fs)*A(fmax(ch).loc,ch)+exp(-i*2*pi*(0:N-1)'*fsig/Fs)*conj(A(fmax(ch).loc,ch));
0083    end;
0084 else
0085    indx = zeros( length(f0) );
0086    for n=1:length(f0);
0087        [fsig,indx(n)]=min(abs(f-f0(n)));
0088    end;
0089    fsig=f(indx);
0090    for ch=1:C;
0091        freqs{ch}=fsig;
0092        Amps{ch}=A(indx,ch);
0093        Nf=length(fsig);
0094 %        fprintf('For channel %d the amplitudes and the Fstatistic at f=%f are \n',ch,f0);
0095 %        fprintf('Fstatistic = %12.8f Fthreshold = %12.8f\n',Fval(indx),sig);
0096 %        fprintf('Real part of amplitude = %12.8f\n',real(A(indx,ch)));
0097 %        fprintf('Imaginary part of amplitude = %12.8f\n',imag(A(indx,ch)));
0098        datafit(:,ch)=exp(i*2*pi*(0:N-1)'*fsig/Fs)*A(indx,ch)+exp(-i*2*pi*(0:N-1)'*fsig/Fs)*conj(A(indx,ch));
0099    end;
0100 end;
0101

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