matlab利用分段线性插值改变采样频率

采样频率不同的我采用《数值分析/计算方法》的分段线性插值，百度一下，说interp1是这个函数>> y=tts('随便说句话');>> t=1:length(y);>>  t3=1:16000/44100:length(y);>>  y3=interp1(t,y,t3);>>  sound(y3,44100);我测试成功了，tts是下载的一个.m文件。默认采样频率16000hz>>  t3=1:16000/newfs:length(y);>>  y3=interp1(t,y,t3);>>  sound(y3,44100);

下面这个是我下载软件就有的了。tts在博文里有。

下载voiceBOX里面也有一个文语转换的可以直接设置采样频率，我竟然卡死在这里现在才发现（用voicebox里面的采样频率可设置,平时看到样例以为是kill原来是11hz）

>> [x,fs]=sapisynth('Hello world','k44100'); >> sound(x,44100);

toolbox->matlab->polyfun

function Vout = interp1(varargin)%INTERP1 1-D interpolation (table lookup)%%   Some features of INTERP1 will be removed in a future release.%   See the R2012a release notes for details.%%   Vq = INTERP1(X,V,Xq) interpolates to find Vq, the values of the%   underlying function V=F(X) at the query points Xq. X must%   be a vector of length N.%   If V is a vector, then it must also have length N, and Vq is the%   same size as Xq.  If V is an array of size [N,D1,D2,...,Dk], then%   the interpolation is performed for each D1-by-D2-by-...-Dk value%   in V(i,:,:,...,:).%   If Xq is a vector of length M, then Vq has size [M,D1,D2,...,Dk].%   If Xq is an array of size [M1,M2,...,Mj], then Vq is of size%   [M1,M2,...,Mj,D1,D2,...,Dk].%%   Vq = INTERP1(V,Xq) assumes X = 1:N, where N is LENGTH(V)%   for vector V or SIZE(V,1) for array V.%%   Interpolation is the same Operation as "table lookup".  Described in%   "table lookup" terms, the "table" is [X,V] and INTERP1 "looks-up"%   the elements of Xq in X, and, based upon their location, returns%   values Vq interpolated within the elements of V.%%   Vq = INTERP1(X,V,Xq,METHOD) specifies alternate methods.%   The default is linear interpolation. Use an empty matrix [] to specify%   the default. Available methods are:%%     'nearest'  - nearest neighbor interpolation%     'linear'   - linear interpolation%     'spline'   - piecewise cubic spline interpolation (SPLINE)%     'pchip'    - shape-PReserving piecewise cubic interpolation%     'cubic'    - same as 'pchip'%     'v5cubic'  - the cubic interpolation from MATLAB 5, which does not%                  extrapolate and uses 'spline' if X is not equally%                  spaced.%%   Vq = INTERP1(X,V,Xq,METHOD,'extrap') uses the interpolation algorithm%   specified by METHOD to perform extrapolation for elements of Xq outside%   the interval spanned by X.%%   Vq = INTERP1(X,V,Xq,METHOD,EXTRAPVAL) replaces the values outside of the%   interval spanned by X with EXTRAPVAL.  NaN and 0 are often used for%   EXTRAPVAL.  The default extrapolation behavior with four input arguments%   is 'extrap' for 'spline' and 'pchip' and EXTRAPVAL = NaN (NaN +NaNi for %   complex values) for the other methods.%%   PP = INTERP1(X,V,METHOD,'pp') will use the interpolation algorithm specified%   by METHOD to generate the ppform (piecewise polynomial form) of V. The%   method may be any of the above METHOD except for 'v5cubic'. PP may then%   be evaluated via PPVAL. PPVAL(PP,Xq) is the same as%   INTERP1(X,V,Xq,METHOD,'extrap').%%   For example, generate a coarse sine curve and interpolate over a%   finer abscissa:%       X = 0:10; V = sin(X); Xq = 0:.25:10;%       Vq = interp1(X,V,Xq); plot(X,V,'o',Xq,Vq)%%   For a multi-dimensional example, we construct a table of functional%   values:%       X = [1:10]'; V = [ X.^2, X.^3, X.^4 ];%       Xq = [ 1.5, 1.75; 7.5, 7.75]; Vq = interp1(X,V,Xq);%%   creates 2-by-2 matrices of interpolated function values, one matrix for%   each of the 3 functions. Vq will be of size 2-by-2-by-3.%%   Class support for inputs X, V, Xq, EXTRAPVAL:%      float: double, single%%   See also INTERPFT, SPLINE, PCHIP, INTERP2, INTERP3, INTERPN, PPVAL.%   Copyright 1984-2013 The MathWorks, Inc.%% Determine input arguments.% Work backwards parsing from the end argument.% Set up the defaultsnarginchk(2,5);[method,extrapval,ndataarg,pp] = parseinputs(varargin{:});if ~isempty(pp)    Vout = pp;    returnend% Set up X, V, and Xq and sanity check the data% At this point we have two possible scenarios% (X,V,Xq) or (V,Xq) and V may not be a vector% if ndataarg ~= 2 or  ndataarg ~=3, errorif ndataarg == 2    V = varargin{1};    if isvector(V)        orig_size_v = size(V);        V = V(:); % Reorient not considered a resize    else        orig_size_v = size(V);        n = orig_size_v(1);        ds = orig_size_v(2:end);        prodDs = prod(ds);        V = reshape(V,[n prodDs]);    end    Xq = varargin{2};    X =(1:size(V,1))';elseif ndataarg == 3    X = varargin{1};    if ~isnumeric(X)        error(message('MATLAB:interp1:Xnumeric'));    end    V = varargin{2};    if isvector(V)        orig_size_v = size(V);        V = V(:); % Reorient not considered a resize    else        orig_size_v = size(V);        n = orig_size_v(1);        ds = orig_size_v(2:end);        prodDs = prod(ds);        V = reshape(V,[n prodDs]);    end    X = X(:);    if any(diff(X)<0)        [X, idx] = sort(X);        V = V(idx,:);    end    Xq = varargin{3};else    error(message('MATLAB:interp1:nargin'));endif ~isfloat(V)    error(message('MATLAB:interp1:NonFloatValues'));endif isscalar(X) && isempty(Xq)    Vout = zeros(size(Xq));    returnendif isvector(V)% V is a vector so size(Vq) == size(Xq)    siz_vq = size(Xq);else    if isvector(Xq)% V is not a vector but Xq is. Batch evaluation.        siz_vq = [length(Xq) orig_size_v(2:end)];    else% Both V and Xq are non-vectors        siz_vq = [size(Xq) orig_size_v(2:end)];    endendif ~isempty(extrapval)    if ~isempty(Xq) && isfloat(Xq) && isreal(Xq)        % Impose the extrap val; this is independent of method        extptids = Xq < X(1) | Xq > X(end);        if any(extptids(:))            Xq = Xq(~extptids);        else            extrapval = [];        end    else        extrapval = [];    endendXqcol = Xq(:);num_vals = size(V,2);if any(~isfinite(V(:))) || (num_vals > 1 && strcmpi(method,'pchip')) ...        || (num_vals == 2 && strcmpi(method,'cubic'))    F = griddedInterpolant(X,V(:,1),method);    if any(strcmpi(F.Method,{'spline','pchip'})) && any(isnan(V(:)))        VqLite = Interp1DStripNaN(X,V,Xq,F.Method);    else        VqLite = zeros(numel(Xqcol),num_vals);        VqLite(:,1) = F(Xqcol);        for iv = 2:num_vals            F.Values = V(:,iv);            VqLite(:,iv) = F(Xqcol);        end    endelse % can use ND    if (num_vals > 1)        Xext = {cast(X,'double'),(1:num_vals)'};        F = griddedInterpolant(Xext,V,method);        VqLite = F({cast(Xqcol,class(Xext{1})),Xext{2:end}});    else        F = griddedInterpolant(X,V,method);        VqLite = F(Xqcol);    endendif ~isempty(extrapval)    if ischar(extrapval)        if ~isreal(V)            extrapval = NaN + 1i*NaN;        else            extrapval = NaN;        end    end    % Vq is too small since elems of Xq were removed.    sizeVqLite = size(VqLite);    Vq = zeros([siz_vq(1) sizeVqLite(2:end)],superiorfloat(X,V,Xq));    Vq(~extptids,:) = VqLite;    Vq(extptids,:)  = extrapval;    % Reshape result, possibly to an ND array    Vout = reshape(Vq,siz_vq);else    VqLite = reshape(VqLite,siz_vq);    Vout = cast(VqLite,superiorfloat(X,V,Xq));endend % INTERP1%-------------------------------------------------------------------------%function Vq = Interp1DStripNaN(X,V,Xq,method)Xqcol = Xq(:);num_value_sets = 1;numXq = numel(Xqcol);if ~isvector(V)    num_value_sets = size(V,2);end% Allocate VqVq = zeros(numXq,num_value_sets);nans_stripped = false;for i = 1:num_value_sets    numvbefore = numel(V(:,i));    [xi, vi] = stripnansforspline(X,V(:,i));    numvafter = numel(vi);    if numvbefore > numvafter        nans_stripped = true;    end    F = griddedInterpolant(xi,vi,method);    if isempty(Xq)        Vq(:,i) = Xqcol;    else        Vq(:,i) = F(Xqcol);    endendif nans_stripped    warning(message('MATLAB:interp1:NaNstrip'));endend%-------------------------------------------------------------------------%function sanitycheck(X,V)if ~isvector(X)    error(message('MATLAB:interp1:Xvector'));endif ~isnumeric(X)    error(message('MATLAB:interp1:Xnumeric'));endif length(X) ~= size(V,1);    if isvector(V)        error(message('MATLAB:interp1:YVectorInvalidNumRows'))    else        error(message('MATLAB:interp1:YInvalidNumRows'));    endendend%-------------------------------------------------------------------------%%     'nearest'  - nearest neighbor interpolation%     'linear'   - linear interpolation%     'spline'   - piecewise cubic spline interpolation (SPLINE)%     'pchip'    - shape-preserving piecewise cubic interpolation%     'cubic'    - same as 'pchip'%     'v5cubic'  - the cubic interpolation from MATLAB 5, which does notfunction methodname = sanitycheckmethod(method)if isempty(method)    methodname = 'linear';    warning(message('MATLAB:interp1:EmptyMethod'));else    if method(1) == '*'        method(1) = [];    end    switch lower(method(1))        case 'n'            methodname = 'nearest';        case 'l'            methodname = 'linear';        case 's'            methodname = 'spline';        case 'c'            methodname = 'pchip';            warning(message('MATLAB:interp1:UsePCHIP'));        case 'p'            methodname = 'pchip';        case 'v'  % 'v5cubic'            methodname = 'cubic';        otherwise            error(message('MATLAB:interp1:InvalidMethod'));    endendend%-------------------------------------------------------------------------%function pp = ppinterp(X,V, orig_size_v, method)%PPINTERP ppform interpretation.n = size(V,1);ds = 1;prodDs = 1;if ~isvector(V)    ds = orig_size_v(2:end);    prodDs = size(V,2);endswitch method(1)    case 'n' % nearest        breaks = [X(1); ...            (X(1:end-1)+X(2:end))/2; ...            X(end)].';        coefs = V.';        pp = mkpp(breaks,coefs,ds);    case 'l' % linear        breaks = X.';        page1 = (diff(V)./repmat(diff(X),[1, prodDs])).';        page2 = (reshape(V(1:end-1,:),[n-1, prodDs])).';        coefs = cat(3,page1,page2);        pp = mkpp(breaks,coefs,ds);    case 'p' % pchip and cubic        pp = pchip(X.',reshape(V.',[ds, n]));    case 's' % spline        pp = spline(X.',reshape(V.',[ds, n]));    case 'c' % v5cubic        b = diff(X);        if norm(diff(b),Inf) <= eps(norm(X,Inf))            % data are equally spaced            a = repmat(b,[1 prodDs]).';            yReorg = [3*V(1,:)-3*V(2,:)+V(3,:); ...                V; ...                3*V(n,:)-3*V(n-1,:)+V(n-2,:)];            y1 = yReorg(1:end-3,:).';            y2 = yReorg(2:end-2,:).';            y3 = yReorg(3:end-1,:).';            y4 = yReorg(4:end,:).';            breaks = X.';            page1 = (-y1+3*y2-3*y3+y4)./(2*a.^3);            page2 = (2*y1-5*y2+4*y3-y4)./(2*a.^2);            page3 = (-y1+y3)./(2*a);            page4 = y2;            coefs = cat(3,page1,page2,page3,page4);            pp = mkpp(breaks,coefs,ds);        else            % data are not equally spaced            pp = spline(X.',reshape(V.',[ds, n]));        endend% Even if method is 'spline' or 'pchip', we still need to record that the% input data V was oriented according to INTERP1's rules.% Thus PPVAL will return Vq oriented according to INTERP1's rules and% Vq = INTERP1(X,Y,Xq,METHOD) will be the same as% Vq = PPVAL(INTERP1(X,Y,METHOD,'pp'),Xq)pp.orient = 'first';end % PPINTERPfunction [method,extrapval,ndataarg,pp] = parseinputs(varargin)method = 'linear';extrapval = 'default';pp = [];ndataarg = nargin; % Number of X,V,Xq args. Init to nargin and reduce.if nargin == 2 && isfloat(varargin{2})    returnendif nargin == 3 && isfloat(varargin{3})    if ischar(varargin{2})        error(message('MATLAB:interp1:nargin'));    end    returnendif ischar(varargin{end})    if strcmp(varargin{end},'pp')        warning(message('MATLAB:interp1:ppGriddedInterpolant'));        if (nargin ~= 4)            error(message('MATLAB:interp1:ppOutput'))        end        method = sanitycheckmethod(varargin{end-1});        % X and V should be vectors of equal length        X = varargin{1};        V = varargin{2};        if isvector(V)            orig_size_v = size(V);            V = V(:); % Reorient not considered a resize        else            orig_size_v = size(V);            n = orig_size_v(1);            ds = orig_size_v(2:end);            prodDs = prod(ds);            V = reshape(V,[n prodDs]);        end        sanitycheck(X,V);        X = X(:);        if isscalar(X)            error(message('MATLAB:interp1:NotEnoughPts'))        end        if any(diff(X)<0)            [X, idx] = sort(X);            V = V(idx,:);        end        griddedInterpolant(X,V(:,1));  % Use this to sanity check the input.        pp = ppinterp(X, V, orig_size_v, method);        return    elseif strcmp(varargin{end},'extrap')        if (nargin ~= 4 && nargin ~= 5)            error(message('MATLAB:interp1:nargin'));        end        if ~(isempty(varargin{end-1}) || ischar(varargin{end-1}))            error(message('MATLAB:interp1:ExtrapNoMethod'));        end        method = sanitycheckmethod(varargin{end-1});        ndataarg = nargin-2;        extrapval = [];        if(strcmp(method,'cubic'))            extrapval = 'default';            warning(message('MATLAB:interp1:NoExtrapForV5cubic'))        end      else        if ischar(varargin{end-1})            error(message('MATLAB:interp1:InvalidSpecPPExtrap'))        end        method = sanitycheckmethod(varargin{end});        needextrapval = ~any(strcmpi(method,{'spline','pchip'}));        if ~needextrapval            extrapval = [];        end        ndataarg = nargin-1;    end    returnendendisscalar = isscalar(varargin{end});if endisscalar && ischar(varargin{end-1})    extrapval = varargin{end};    ndataarg = nargin-2;    method = sanitycheckmethod(varargin{end-1});    return endif endisscalar && isempty(varargin{end-1}) && (nargin == 4 || nargin == 5)    % default method via []    extrapval = varargin{end};    ndataarg = nargin-2;    return endif isempty(varargin{end})    % This is potentially ambiguous, the assumed intent is case I    % I)    X, V, []   Empty query    % II)   V, [], [] Empty query and empty method,    % III)  V, Xq, [] Empty method    if nargin ~= 3        ndataarg = nargin-1;    end    returnendend