3.1. Initialisation

imcalculator.__init__(acc, dt, damping=0.05, unit='g')[source]

Initializes the imcalculator with the input ground-motion record.

The acceleration is converted to g on input so that all downstream methods use a consistent unit system. The original unit label is stored in self.unit for reference.

Parameters:

  • acc (list or numpy.ndarray) – Acceleration time series. Units are specified by the unit parameter.

  • dt (float) – Time step of the accelerogram (s).

  • damping (float, optional) – Damping ratio (default is 0.05, i.e. 5%).

  • unit (str, optional) – Unit of the input acceleration. Accepted values are "g" (default), "m/s2", or "m/s^2".

Raises:

ValueError – If unit is not one of the accepted strings.