audio - wavread error in vibrato function matlab -

i trying compile vibrato sound effect code found on internet. code has function call wavread, in function matlab showing error, i've search codes , every code use function open de wav file, happening? code below:

vibrato script:

clear all; close all; clc;  infile = 'musica.wav';  % read in wav sample [ x, fs, n ] = wavread(infile);   %set parameters vibrato % change these experiment vibrato  modfreq = 10; %10 khz width = 0.0008; % 0.8 milliseconds  % vibrato  yvib = vibrato(x, fs, modfreq, width);  % write output wav files wavwrite(yvib, fs,  'out_vibrato.wav');  % plot original , equalised waveforms  figure(1) hold on plot(x(1:500),'r'); plot(yvib(1:500),'b'); title('vibrato first 500 samples'); 

vibrato function:

% vibrato  function y=vibrato(x,samplerate,modfreq,width) ya_alt=0; delay=width; % basic delay of input sample in sec delay=round(delay*samplerate); % basic delay in # samples width=round(width*samplerate); % modulation width in # samples if width>delay    error('delay greater basic delay !!!');   return; end modfreq=modfreq/samplerate; % modulation frequency in # samples len=length(x);        % # of samples in wav-file l=2+delay+width*2;    % length of entire delay   delayline=zeros(l,1); % memory allocation delay y=zeros(size(x));     % memory allocation output vector  n=1:(len-1)    m=modfreq;    mod=sin(m*2*pi*n);    zeiger=1+delay+width*mod;    i=floor(zeiger);    frac=zeiger-i;    delayline=[x(n);delayline(1:l-1)];     %---linear interpolation-----------------------------    y(n,1)=delayline(i+1)*frac+delayline(i)*(1-frac);      %---allpass interpolation------------------------------    %y(n,1)=(delayline(i+1)+(1-frac)*delayline(i)-(1-frac)*ya_alt);      %ya_alt=ya(n,1); end  

the error appears:

undefined function or variable 'wavread'.

in line:

[ x, fs, n ] = wavread(infile);