More matlab samples

test/fixtures/matlab/average.m

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+function y = average(x)
+% AVERAGE Mean of vector elements.
+% AVERAGE(X), where X is a vector, is the mean of vector
+% elements. Nonvector input results in an error.
+[m,n] = size(x);
+if (~((m == 1) | (n == 1)) | (m == 1 & n == 1))
+    error('Input must be a vector')
+end
+y = sum(x)/length(x);

test/fixtures/matlab/make_filter.m

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+function [filtfcn, statefcn] = makeFilter(b, a)
+%   FILTFCN = MAKEFILTER(B, A) creates an IIR filtering
+%   function and returns it in the form of a function handle,
+%   FILTFCN. Each time you call FILTFCN with a new filter 
+%   input value, it computes the corresponding new filter 
+%   output value, updating its internal state vector at the
+%   same time.
+%
+%   [FILTFCN, STATEFCN] = MAKEFILTER(B, A) also returns a 
+%   function (in the form of a function handle, STATEFCN) 
+%   that can return the filter's internal state.  The internal
+%   state vector is in the form of a transposed direct form 
+%   II delay line.
+
+%   Initialize state vector. To keep this example a bit 
+%   simpler, assume that a and b have the same length.  
+%   Also assume that a(1) is 1.
+
+v = zeros(size(a));
+
+filtfcn =  @iirFilter;
+statefcn = @getState;
+
+   function yn = iirFilter(xn)
+      % Update the state vector
+      v(1) = v(2) + b(1) * xn;
+      v(2:end-1) = v(3:end) + b(2:end-1) * xn - ...
+         a(2:end-1) * v(1);
+      v(end) = b(end) * xn - a(end) * v(1);
+      
+      % Output is the first element of the state vector.
+      yn = v(1);
+   end
+
+   function vOut = getState
+      vOut = v;
+   end
+end