CSTRAIN - A FORTRAN-77 PROGRAM TO STUDY FRY PLOTS IN 2-DIMENSIONAL SIMULATED MODELS

This paper presents a CSTRAIN program, written in FORTRAN 77, which co uld help to study and understand Fry plots using Fry's center-to-cente r method for finite strain analysis in deformed rocks. The program can be used to generate two-dimensional isotropic distributions with diff ering degrees of anticlustering, ranging from random to strongly antic lustered distributions. These point distributions can be deformed homo geneously by pure shear and rotation to provide any desired strain rat io and orientation of Fry plot. Also, the program allows separate rota tion and superposition of different fields. Plots of point distributio n before or after deformation, and corresponding Fry plots, can be pro duced for any field using either GINO or CALCOMP graphic subroutines. A description for the program is given with sample Fry plots together with the program listing.