Direct integration leads to the potential gradient of a rectangular plate. Lines with equal spacing form a grid for integration over the infinite plane A source distribution is approximated by pattern functions which are centered over each grid point. The pattern functions are based upon the sine quotient function. Fourier analysis replaces integration in physical space with integration in wave number space The range of integration is limited to lines of finite length in wave number space. The computation of potential gradient is provided by subroutines.

http://archive.org/details/potentialgradien00hers