Barry -- Will try it.
> ... since, presumably, other more powerful IO tools exist that would be used for "real" problems? I know there are tools for snapshotting from PETSc, e.g. VecView to .vtk. In fact petsc binary seems fairly convenient for that. On the other hand, I am not sure I've ever done anything "real". ;-) Anyone out there: Are there a good *convenient* tools for saving space/time-series (= movies) from PETSc TS? I want to add frames and movies from PETSc into slides, etc. I can think of NetCDF but it seems not-very-convenient, and I am worried not well-supported from PETSc. Is setting up TS with events (=TSSetEventMonitor()) and writing separate snapshot files the preferred scalable usage, despite the extra effort compared to "-ts_monitor_solution binary:foo.dat"? Ed On Mon, Feb 29, 2016 at 8:53 PM, Barry Smith <[email protected]> wrote: > > Ed, > > I have added a branch barry/feature-ts-monitor-binary that supports > -ts_monitor binary:timesteps that will store in simple binary format each > of the time steps associated with each solution. This in conjugation with > -ts_monitor_solution binary:solutions will give you two files you can read > in. But note that timesteps is a simple binary file of double precision > numbers you should read in directly in python, you cannot use > PetscBinaryIO.py which is what you will use to read in the solutions file. > > Barry > > Currently PETSc has a binary file format where we can save Vec, Mat, IS, > each is marked with a type id for PetscBinaryIO.py to detect, we do not > have type ids for simple double precision numbers or arrays of numbers. > This is why I have no way of saving the time steps in a way that > PetscBinaryIO.py could read them in currently. I don't know how far we want > to go in "spiffing up" the PETSc binary format to do more elaborate things > since, presumably, other more power IO tools exist that would be used for > "real" problems? > > > > On Feb 29, 2016, at 3:24 PM, Ed Bueler <[email protected]> wrote: > > > > Dear PETSc -- > > > > I have a short C ode code that uses TS to solve y' = g(t,y) where y(t) > is a 2-dim'l vector. My code defaults to -ts_type rk so it does adaptive > time-stepping; thus using -ts_monitor shows times at stdout: > > > > $ ./ode -ts_monitor > > solving from t0 = 0.000 with initial time step dt = 0.10000 ... > > 0 TS dt 0.1 time 0. > > 1 TS dt 0.170141 time 0.1 > > 2 TS dt 0.169917 time 0.270141 > > 3 TS dt 0.171145 time 0.440058 > > 4 TS dt 0.173931 time 0.611203 > > 5 TS dt 0.178719 time 0.785134 > > 6 TS dt 0.0361473 time 0.963853 > > 7 TS dt 0.188252 time 1. > > error at tf = 1.000 : |y-y_exact|_inf = 0.000144484 > > > > I want to output the trajectory in PETSc binary and plot it in python > using bin/PetscBinaryIO.py. Clearly I need the times shown above to do > that. > > > > Note "-ts_monitor_solution binary:XX" gives me a binary file with only y > values in it, but not the corresponding times. > > > > My question is, how to get those times in either the same binary file > (preferred) or separate binary files? I have tried > > > > $ ./ode -ts_monitor binary:foo.dat # invalid > > $ ./ode -ts_monitor_solution binary:bar.dat # no t in file > > $ ./ode -ts_monitor_solution binary:baz.dat -ts_save_trajectory # no t > in file > > > > without success. (I am not sure what the boolean option > -ts_save_trajectory does, by the way.) > > > > Thanks! > > > > Ed > > > > PS Sorry if this is a "RTFM" question, but so far I can't find the > documentation. > > > > > > -- > > Ed Bueler > > Dept of Math and Stat and Geophysical Institute > > University of Alaska Fairbanks > > Fairbanks, AK 99775-6660 > > 301C Chapman and 410D Elvey > > 907 474-7693 and 907 474-7199 (fax 907 474-5394) > > -- Ed Bueler Dept of Math and Stat and Geophysical Institute University of Alaska Fairbanks Fairbanks, AK 99775-6660 301C Chapman and 410D Elvey 907 474-7693 and 907 474-7199 (fax 907 474-5394)
