  Nowadays, micromagnetic simulations are a common tool for studying a wide
range of different magnetic phenomena, including the ferromagnetic resonance. A
technique for evaluating reliability and validity of different micromagnetic
simulation tools is the simulation of proposed standard problems. We propose a
new standard problem by providing a detailed specification and analysis of a
sufficiently simple problem. By analyzing the magnetization dynamics in a thin
permalloy square sample, triggered by a well defined excitation, we obtain the
ferromagnetic resonance spectrum and identify the resonance modes via Fourier
transform. Simulations are performed using both finite difference and finite
element numerical methods, with \textsf{OOMMF} and \textsf{Nmag} simulators,
respectively. We report the effects of initial conditions and simulation
parameters on the character of the observed resonance modes for this standard
problem. We provide detailed instructions and code to assist in using the
results for evaluation of new simulator tools, and to help with numerical
calculation of ferromagnetic resonance spectra and modes in general.
