# 27.5 Program AVQ, average Q-relations

Q as a function of frequency is usually described as

If several such relations are to be averaged, it is not just a question of averaging the parameters. In program AVQ, the averaging is done in the following way:

-For each relation, 1/Q is calculated at the frequencies 1, 2, 4, 8 and 16 Hz. -At each frequency, average 1/Q is calculated using the number of observations in the original determination of Q for a particular relation as weight. -A new least squares determination of in is made with the Q-values.

The program uses an input file with q0, v and number of observations, one relation (free format) per line. An example of a run is seen below:

C:\seismo\wor>avq
File name, enter for automag_grid.out
input.txt
Q0,alpha,n   100.000000      0.500000000             100
Q0,alpha,n   150.000000      0.300000012              50
Q0,alpha,n   200.000000      0.200000003              10
Q0,alpha,n   170.000000      0.400000006              22
Q0,alpha,n   250.000000      0.150000006               5
Q0,alpha,n   80.0000000      0.800000012              10
Number of curves to average:            6
Running average over how many, enter for average of all?

Q0,alpha,corr   119.819160      0.437137932      0.999868274

Output of plot in avq.eps


and the plot seen in figure 27.4 comes up.

The program also has a special input to be used with AUTOMAG, which can output Q-relations found by grid search, see AUTOMAG for more details. These relations can be averaged over a number of relations. However, here that option is not used.

Peter Voss : Fri Nov 12 10:33:10 UTC 2021