Matlab draws short-term average amplitude spectrum

And the last section matlab Draw a short-term energy diagram The difference is that , The last section is to find the square , Now it's the absolute value . But the figure obtained is the same as that in the previous section , Short time average amplitude spectrum comparison Short time energy spectrum The advantage of is to save computation , And there will be no calculation overflow error .

fid=fopen('zqq.txt', 'rt');
x=fscanf(fid, '%f');
fclose(fid);

% The calculated window length is 50, Frame shift =0 Speech energy at 
s=fra(50, 50, x);% The frame length is 50 A digital , Move frame to 50 A digital ,  obtain s by 1319 That's ok ,50 Columns of the matrix . That is, every line has 50 A digital , this 50 A number is a frame 
%disp(length(s2));
%disp(size(s2, 1));
%disp(size(s2, 2));
s2=abs(s);
%b=sum(a,dim); a According to matrix ;dim be equal to 1 perhaps 2,1 Indicates that each column is summed ,2 Means that each line is summed ; Indicates whether to sum every column or row ;b Represents the obtained row vector 
energy=sum(s2, 2);% The matrix s2 Sum each line , energy by 1319 That's ok ,1 Column , That is, each number represents a frame of energy 
%disp(size(energy, 1));
%disp(size(energy, 2));
subplot(2, 2, 1);
plot(energy);
xlabel(' frames ');
ylabel(' Short term energy E');
legend(' Window length N=50');
axis([0, 1500, 0, 10*10^5]);

% The calculated window length is 100, Frame shift =0 Speech energy at 
s=fra(100, 100, x);
s2=abs(s);
energy=sum(s2, 2);
subplot(2, 2, 2);
plot(energy);
xlabel(' frames ');
ylabel(' Short term energy E');
legend(' Window length N=100');
axis([0, 750, 0, 2*10^6]);

% The calculated window length is 400, Frame shift =0 Speech energy at 
s=fra(400, 400, x);
s2=abs(s);
energy=sum(s2, 2);
subplot(2, 2, 3);
plot(energy);
xlabel(' frames ');
ylabel(' Short term energy E');
legend(' Window length N=400');
axis([0, 190, 0, 7*10^6]);

% The calculated window length is 800, Frame shift =0 Speech energy at 
s=fra(800, 800, x);
s2=abs(s);
energy=sum(s2, 2);
subplot(2, 2, 4);
plot(energy);
xlabel(' frames ');
ylabel(' Short term energy E');
legend(' Window length N=800');
axis([0, 95, 0, 14*10^6]);

function f=fra(len, inc, x)
    %len Is the frame length ,inc Shift for the frame length by one frame 
    %size(X,1), Return matrix X The number of rows ;
    %size(X,2), Return matrix X Columns of ;
    %disp(size(x, 1));
    fh=fix(((size(x, 1) - len)/inc) + 1);% Count the frames ,fh=1319
    %disp(fh);
    f=zeros(fh, len);%fh That's ok ,len Column 0 matrix , Here is 1319 That's ok ,50 Column 0 matrix 
    i=1; n=1;
    while i<=fh
        j=1;
        % The following loop is to fill one line at a time 50 A digital , That's a frame , Fill in a line , Add the number of rows 1 Then fill in again 
        while j<=len
            f(i, j)=x(n);
            j=j+1;
            n=n+1;
        end
        n=n-len+inc;% n-len Represents that it will be restored to the end of the previous frame ,+inc It means to move at the end of the previous frame inc length  
        i=i+1;
    end
end