Thanks, your approach is the most convincing. Martin
> On Jul 15, 2023, at 3:15 PM, Raul Miller <rauldmil...@gmail.com> wrote: > > I think the approaches you described are fine. > > That said, another approach would be to think of your dataset as a > table -- one row for each atom, with each column having different > significance. coordinate x,y, z; velocity x,y,z; force x,y,z, So, if > you had 42 atoms, your data would be a 42 by 9 matrix. > > Or, perhaps it would be better to distinguish x,y,z from > coordinate/velocity/force (the 42 atom example being represented with > a 42 by 3 by 3 array or perhaps more conveniently a 3 by 42 by 3 > array). > > This last approach might have an implementation something like: > > do_step=: positions_update, velocities_update,: forces_update > > where each of the update verbs obtains the requisite information from > its y argument. > > I hope this makes sense, > > -- > Raul > > > On Sat, Jul 15, 2023 at 8:18 AM Marcin Żołek > <marcin.zo...@students.mimuw.edu.pl> wrote: >> >> I am learning J and writing a program in this language to simulate a >> physical phenomenon of interactions between atoms (each atom is described by >> coordinates, velocities, forces, etc.). I am wondering how to store data in >> such a simulation. >> >> The simulation involves applying a function that performs a single >> simulation step several times: >> >> do_step^:42 initial_data >> >> Simulation step consists of several substeps. Which storage option is better >> or is there other way than the ones listed below? >> >> 1) Data stored in public nouns (one noun is a matrix of coordinates of >> atoms, another noun is a matrix of velocities of atoms, etc.). Then do_step >> calls substep functions that overwrites these public nouns: >> >> do_step =: monad define >> velocities =: forces update_velocities velocities >> positions =: velocities update_positions positions >> ... >> ) >> >> 2) Data stored in an array of boxes (in the first box an array of >> coordinates of atoms, in the second box an array of velocities of atoms, >> etc.). Then do_step is the composition of all substep functions and each >> substep function is a monad that creates modified array of boxes using m} : >> >> do_step =: monad : 'do_substep_k ... do_substep_2 do_substep_1 y' >> >> Martin >> ---------------------------------------------------------------------- >> For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
