Matlab Filter Implementation



In this section, we will implement (in matlab) the simplest lowpass filter



$\displaystyle y(n) = x(n) + x(n-1),\ n=1,2,\ldots,N $



(from Eq.$ \,$(1.1)). For the simplest lowpass filter, we had two program listings:



Fig.1.3 listed simplp for filtering one block of data, and

Fig.1.4 listed a main program for testing simplp.



In matlab, there is a built-in function called filter3.3 which will implement simplp as a special case. The syntax is



y = filter (B, A, x)



where



x is the input signal (a vector of any length),

y is the output signal (returned equal in length to x),

A is a vector of filter feedback coefficients, and

B is a vector of filter feedforward coefficients.



The filter function performs the following iteration over the elements of x to implement any causal, finite-order, linear, time-invariant digital filter:3.4 -Matlab Filter Implementation



In this section, we will implement (in matlab) the simplest lowpass filter



$\displaystyle y(n) = x(n) + x(n-1),\ n=1,2,\ldots,N $



(from Eq.$ \,$(1.1)). For the simplest lowpass filter, we had two program listings:



　　Fig.1.3 listed simplp for filtering one block of data, and

　　Fig.1.4 listed a main program for testing simplp.



In matlab, there is a built-in function called filter3.3 which will implement simplp as a special case. The syntax is



　　　　y = filter (B, A, x)



where



　　x is the input signal (a vector of any length),

　　y is the output signal (returned equal in length to x),

　　A is a vector of filter feedback coefficients, and

　　B is a vector of filter feedforward coefficients.



The filter function performs the following iteration over the elements of x to implement any causal, finite-order, linear, time-invariant digital filter:3.4