Complete MATLAB Implementation of FIR/IIR Low-pass and Band-pass Filters with Graphical Comparisons

This complete program represents my substantial development effort in creating robust MATLAB implementations of digital filters. The code showcases practical applications of both FIR (using windowing methods and frequency sampling techniques) and IIR filters (employing Butterworth, Chebyshev, or elliptic design approaches) for low-pass and band-pass filtering operations. The implementation includes key MATLAB functions such as fir1 for FIR filter design and butter/yulewalk for IIR filter synthesis, with proper parameter configuration for cutoff frequencies and filter orders. The program generates comprehensive graphical comparisons displaying original signals alongside their filtered counterparts, demonstrating frequency domain transformations and time-domain signal smoothing effects. The visualization components utilize MATLAB's plotting capabilities to show magnitude response, phase characteristics, and time-domain signal comparisons, providing clear insights into filter performance and frequency attenuation properties. This practical demonstration helps users understand fundamental DSP concepts including frequency response, stopband attenuation, and passband ripple characteristics through executable code examples. I believe this resource will be valuable for understanding digital filter implementation methodologies and their practical applications in signal processing scenarios.