How to output the fluid displace in poroelastic model

I would like to output the fluid displace and solid displace at the same time,in an isotropic poroelastic.In DATA/Par_file,set parameters about receivers,the seismotype just have six record,1=displ 2=veloc 3=accel 4=pressure 5=curl of displ 6=the fluid potential.It is missing the parameters i want–the fluid displace.How can i output this parameter?
Thanks and Kind Regards,
jun li

by default, the displacement/velocity/acceleration from a station within a poroelastic element will be coming from the solid wavefield part (displs_poroelastic/…), the fluid displacement (displw_poroelastic/…) is not output and implemented yet.

the easiest would be you change the code line with the corresponding wavefield you want in file src/specfem2D/write_seismograms.F90, see:

Thank you very much for your answer.i will try your suggestion to modify write_seismograms.F90.
Best wishes,
Jun li

i modify write_seismograms.f90,then i output the fluid displace.
i just modify case (1)
! displacement
call compute_vector_one_element
modify displs_poroelastic to displw_poroelastic.then i calculate one example,the result of the calculation seems to be wrong.
according to Biot’s theroy,the fast P waves in the solid and fluid,their phase is same. the slow P waves in the solid and fluid,their phase is opposite.However,the actual calculation result is not like this.I compared the calculation results of the half-space with the theoretical results and found that the solid displacement results correspond well, and the fast P waves of the fluid displacement are in opposite phase to the theoretical ones, and their amplitudes are also very small.The following is a comparison between my results and theoretical results,
our parameters are somewhat different, but the biggest problem is that the waveforms do not completely correspond.
I have calculated the response of single-layer and two-layer porous media. The solid phase displacement and velocity parameters are all correct. Therefore, I think the program should be correct. However, I only changed one output and the fluid displacement was wrong.
I hope you can give some advice,any advice is greatly appreciated.
Thanks for your help.
jun li