The work presented in this thesis was motivated by the need to provide a better means of understanding electromagnetic radiation mechanisms. In the past, empirical techniques were used to analyze antenna structures; however, these techniques were quite limited since the probes used to measure the near-field quantities altered the operation of the antenna. A number of publications have demonstrated that computational algorithms can be used to accurately simulate the near-field behavior of an antenna. In this thesis, visualization capabilities and image-processing techniques have been developed to aid in the interpretation of the large data sets generated by computational codes. The effectiveness of these methods has been demonstrated using two canonical cases: a microstrip patch antenna and an open-ended rectangular waveguide. In Chapter 2, we defined the essential components of a visualization capability. A post-processing routine was developed that interfaced the computational algorithm with the visualization software. That essentially involved a restructuring of the raw data file along with a change of data types. Additionally, phasor-domain data was transformed to the steady-state time-domain. By performing that conversion, we were able to view the magnitude and phase information simultaneously as an animation, which made the analysis of the data somewhat easier. Also in Chapter 2, we provided an overview of the visualization software. The various shading techniques used by the visualization package were analyzed in order to determine what effect they had on the data. Finally, we discussed methods of visualizing vector information.