A question about recorder of stiffness

[ericven]

hello
I want to use the Stiffness Recorder to capture the stiffness of a section
and I got the output file in which four values (except time history) are shown in a row.
but, I don't know what the four values represent for. In other words, are they the four elements of the stiffness matrices ?

please help me ,thank you !

[selimgunay]

The four columns should be time and axial, flexural and torsional stiffness. Could you check which is which using an elastic section?

[EricsonEncinaZ]

When defining a recorder if the flag -xml is added instead of -file, the recorded file should have headers showing what each column is.

[ericven]

Thank you for your reply!
I have a new problem now, please help me.
I draw the section stiffness curve varying with seismic time-history by MATLAB.
But the curve is not monotonous , it descends and recovers sharply at some time point.
I think there is no wrong with my model. So, I want to know what the stiffness which I got with the stiffness recorder command means ?