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diff --git a/macros/alignsignals.sci b/macros/alignsignals.sci new file mode 100644 index 0000000..2013e3b --- /dev/null +++ b/macros/alignsignals.sci @@ -0,0 +1,166 @@ +function varargout = alignsignals(x,y,varargin) +//This function aligns the two input signals. +// +//Calling Sequence +//[Xa Ya] = ALIGNSIGNALS(X,Y) +//[Xa Ya] = ALIGNSIGNALS(X,Y,MAXLAG) +//[Xa Ya] = ALIGNSIGNALS(X,Y,MAXLAG,1) +//[Xa Ya D] = ALIGNSIGNALS(...) +// +//Description +//[Xa Ya] = ALIGNSIGNALS(X,Y) aligns the two vectors X and Y by estimating +//the delay D between the two. If Y is delayed with respect to X, D is +// positive , and X is delayed by D samples. If Y is advanced with respect +// to X, D is negative, and Y is delayed by -D samples. +// +// [Xa Ya] = ALIGNSIGNALS(X,Y,MAXLAG) considers MAXLAG be the maximum correlation +// window size which is used to calculate the estimated delay D between X and Y. +// MAXLAG is an integer-valued scalar. By default, MAXLAG is equal to MAX(LX,LY)-1. +// If MAXLAG is empty ([]),then default value is considered. If MAXLAG +// is negative, it is replaced by its absolute value. +// +// [Xa Ya] = ALIGNSIGNALS(X,Y,MAXLAG,1) keeps the lengths of Xa +// and Ya the same as those of X and Y, respectively. +// Here, 1 implies truncation of the intermediate vectors. +// Input argument 4 is 0 implies truncation_off (no truncation). +// D is positive implies D zeros are pre-pended to X, and the last D samples of X are truncated. +// D is negative implies -D zeros are pre-pended to Y, and the last -D samples +// of Y are truncated. That means, when D>=Length(X), all samples of X are lost. +// Similarly, when -D>=Length(Y), all samples of Y are lost. +// Avoid assigning a specific value to MAXLAG when using the truncate=1 option, set MAXLAG to []. +// +// [Xa Ya D] = ALIGNSIGNALS(...) returns the estimated delay D. +// +// Examples +// X = [0 0 0 1 2 3 ]; +// Y = [1 2 3 ]; +// [Xa,Ya] = alignsignals(X,Y,[],1) +// +// See also +// finddelay +// +// Authors +// Pola Lakshmi Priyanka, IIT Bombay// + +// Check number of input arguments +[out_a,inp_a]=argn(0) + +if inp_a<=1 | inp_a>4 then + error('comm:alignsignals: Invalid number of input arguments') +end + + +if out_a>3 then + error('comm:alignsignals: Invalid number of output arguments') +end + +//Check input arguments +if (~or(type(x)==[1 5 8]) | ~isvector(x) ) + error('comm:alignsignals:Input argument 1 should be a vector of numbers'); +end + +[row_x,col_x] = size(x); +len_x = length(x); + + +if (~or(type(y)==[1 5 8]) | ~isvector(y) ) + error('comm:alignsignals:Input argument 2 should be a vector of numbers'); +end + +[row_y,col_y] = size(y); +len_y = length(y); + +//Check for MaxLag +if inp_a==3 then + maxlag = varargin(1) +else + maxlag = max(len_x,len_y)-1; //Default value +end + +if ~isempty(maxlag) then + if ( ~or(type(maxlag)==[1 5 8]) | ~isreal(maxlag) | length(maxlag)~=1 | ceil(maxlag)~=maxlag), + error('comm:alignsignals:Input argument 3 should be a scalar integer'); + elseif (( isnan(maxlag)) | isinf(maxlag)), + error('comm:alignsignals:Input argument 3 can not be Inf or NAN'); + end +else + maxlag = maxlag_default; +end + +maxlag = double(abs(maxlag)); + +//Check for truncate +trunc_on=0; +if inp_a==4 + if (varargin(2)) + trunc_on=1; + end +end + + +// Estimate delay between X and Y. +if inp_a==2 + d = finddelay(x,y); +else + d = finddelay(x,y,maxlag); +end + + +if d == 0 // X and Y are already aligned. + varargout(1) = x; + varargout(2) = y; +elseif d > 0 // Y is estimated to be delayed with respect to X. + if row_x>1 // X is entered as a column vector. + if trunc_on==0 + varargout(1) = [zeros(d,1) ; x]; + else + if d>=row_x + warning('comm:alignsignals:firstInputTruncated'); + varargout(1) = zeros(row_x,1); + else + varargout(1) = [zeros(d,1) ; x(1:len_x-d)]; + end + end + else // X is entered as a row vector. + if trunc_on==0 + varargout(1) = [zeros(1,d) x]; + else + if d>=col_x + warning('comm:alignsignals:firstInputTruncated'); + varargout(1) = zeros(1,col_x); + else + varargout(1) = [zeros(1,d) x(1:len_x-d)]; + end + end + end + varargout(2) = y; +else // X is estimated to be delayed with respect to Y. + varargout(1) = x; + if row_y>1 // Y is entered as a column vector. + if trunc_on==0 + varargout(2) = [zeros(-d,1) ; y]; + else + if (-d)>=row_y + warning('comm:alignsignals:secondInputTruncated'); + varargout(2) = zeros(row_y,1); + else + varargout(2) = [zeros(-d,1) ; y(1:len_y-(-d))]; + end + end + else // Y is entered as a row vector. + if trunc_on==0 + varargout(2)= [zeros(1,-d) y]; + else + if (-d)>=col_y + warning('comm:alignsignals:secondInputTruncated'); + varargout(2) = zeros(1,col_y); + else + varargout(2) = [zeros(1,-d) y(1:len_y-(-d))]; + end + end + end +end + +varargout(3) = d; + +endfunction |