Reference problem
=====================

Several signal readings are to be carried out:


* reading a non-centered accelerogram (maximum amplitudes :math:`>0` and :math:`<0` different) expressed in :math:`g` (:math:`9.81{\mathrm{m.s}}^{-2}`) and looking for the maximum amplitude,


* calculation of oscillator spectra for reduced damping :math:`\xi =0.01` (:math:`1\text{\%}`) with calculation options:


* pseudo-absolute acceleration and regain the high frequency training acceleration (:math:`f\ge 100\mathrm{Hz}`),


* relative displacement,


* reading a centered accelerogram (LBEW: Long Beach East West earthquake) and looking for the maximum amplitude,


* calculation of the oscillator spectrum in absolute pseudo-acceleration,


* reading an oscillator spectrum in free format.