Running average from vector of data

Hi, I have a vector A A = (1 ,3 ,4 -2, 5 ,6 8, 9, -4, -2)

I want to create a vector with the running average such that

B = (A1, (A1+A2)/2, (A1+A2+A3)/3, ....) then plot(B)

Thanks!

Answer 1

[James Tursa]

x = 1:numel(AA);
B = cumsum(AA)./x;
plot(x,B);

Answer 2

[Image Analyst]

If you have the Curve Fitting Toolbox, try smooth: http://www.mathworks.com/help/curvefit/smooth.html?searchHighlight=smooth

Otherwise, use conv() (twice) and plot().

% Create sample data.
signal = randi(9, 1, 5)
% Make a moving window (kernel) to do the counting.
kernel = [1, 1, 1];
% Count the number of elements in the moving window.
counts = conv(ones(1, length(signal)), kernel, 'full')
% Sum the signal in the moving window.
sums = conv(signal, kernel, 'full')
% Divide the sums by the counts to get the average.
movingAverage = sums ./ counts
plot(movingAverage, 'b-', 'LineWidth', 3);
grid on;

Sample data:

signal =
     3     2     8     2     1
counts =
     1     2     3     3     3     2     1
sums =
     3     5    13    12    11     3     1
movingAverage =
    3.0000    2.5000    4.3333    4.0000    3.6667    1.5000    1.0000