# 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:

- findpeaks Helper function to find peaks in a given continuous valued time series x
- ftestc computes the F-statistic for sine wave in locally-white noise (continuous data).
- change_row_to_column Helper routine to transform 1d arrays into column vectors that are needed
- dpsschk Helper function to calculate tapers and, if precalculated tapers are supplied,
- getparams Helper function to convert structure params to variables used by the

This function is called by:

- rmlinesc removes significant sine waves from data (continuous data).
- rmlinesmovingwinc fits significant sine waves to data (continuous data) using overlapping windows.

## 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