***compare t_file_file

Description

This comparison is used to compare two files (names fname1 et fname2) with a time-weighted averaging. Files are “columns” files containing doubles. For each file, one considers a relation \(y_i(t),\;i=1,2\) interpolated from columns y1 and t1. To compare two files, one considers the instersection of columns t1 and t2. One defines

(504)\[t_- = \max \left( \min_{t\in t1}, \min_{t\in t2} \right) \qquad t_+ = \min \left( \max_{t\in t1}, \max_{t\in t2} \right)\]

The function to be optimized is given by:

(505)\[{\cal F}_i = \frac{1}{{2(t_+ - t_-)}} \int_{t_-}^{t_+} \left( y_2(t)-y_1(t) \right)^{2}\,dt\]

The optimization variables \(x\) should affect one of the two files fname1 or fname2.

Note

Because of the time weighting of the error, the density of comparison points is not important for the comparison function (although more points will be more accurate). Also, if the time scale of a test changes this method can totally miss important features of the response. For example, if a hold-time loading profile of 10s-300s-10s is applied, the emphasis will be on the response during 300s. Any details of the 10s segments will essentially be lost.

Syntax

t_file_file fname1 t1 y1 fname2 t2 y2 \(~\,~\,~\,~\,\) [weight vweight]