Interactive computations and display of characteristics of the radiation scattered by a sphere: A demonstration for PS/2 Model 80
by P. Halpern, J. V. Dave
The Personal System/2® (PS/2®) Model 80 with its math coprocessor provides a considerable amount of computing power which can be used with advantage to solve technical problems interactively at a stand-alone workstation. To demonstrate this capability, a scientific program routinely used in diverse disciplines requiring significant computing power was modified to run on the PS/2 Model 80. It computes and displays variations of the specific intensity and degree of polarization of the electromagnetic radiation scattered by a sphere of given refractive index. For a sphere of size parameter of 100, about 475 double-precision floating-point calculations are performed and the results displayed in graphic format in less than ten seconds. The selected algorithm is routinely used in several different disciplines such as astronomy, atmospheric optics, chemical engineering, colloidal chemistry, and remote sensing. Because it requires the evaluation of spherical Bessel functions with complex arguments, and derivatives of the Legendre polynomials, it was selected as a representative problem of numerically intensive computing.