This document specifies new formats for
- hydro full evolution
- hydro hypersurfaces
- particle evolution
These formats aim to be as simple and flexible as possible while still containing all necessary information. Ideally, existing files should be convertible by simply prepending several comment lines.
-
Space-separated columns.
-
Lines prefixed with
#are comments. Any line that is not a comment or blank contains data. -
The type of file and column order is specified in the first line of the file via a shebang-style comment line beginning with
#!. The purpose of the#!is to provide a special comment that may be ignored by simple parsers but contains specific information that some programs require. See following sections for details. -
Multiple events may be present in a single file and are separated by one or more blank or comment lines.
-
Multiple files may be concatenated together.
The shebang line must be the first line of the file. It specifies the file type and order of data columns:
#!OSCAR2013 filetype columns
where
filetype ::= (full-evolution nt nx ny nz | hypersurface | particles)
columns ::= column1 [column2 ...]
Each columnN is a label for the quantity in that data column. The acceptable columns are different for each file
type, see following sections. Columns may be specified in arbitrary order.
The shebang line has the following format:
#!OSCAR2013 full-evolution nt nx ny nz columns
where nt, nx, ny, nz are the total numbers of grid points in each dimension. nz = 1 for boost-invariant
hydro. The minimal set of columns is
it ix iy iz : t,x,y,z indices
t x y z : coordinates of fluid cell
vx vy vz : fluid flow velocity
e p T : energy density, pressure, temperature
t x y z may be replaced by tau x y eta.
For example, suppose a hydro code runs on a 51 x 51 x 51 spatial grid, steps of 0.5 fm from -12.5 to 12.5 fm, with 100 timesteps from 0 to 10 fm. The following would be a valid file:
#!OSCAR2013 full-evolution 100 50 50 50 it ix iy iz t x y z vx vy zx e p T
# this is a comment and will be ignored
# data begins on next line
0 0 0 0 0.0 -12.5 -12.5 -12.5 1.0 1.0 1.0 2.0 3.0 4.0
0 1 0 0 0.0 -12.0 -12.5 -12.5 1.1 0.9 1.2 2.2 3.3 4.4
...
1 0 0 0 0.1 -12.5 -12.5 -12.5 1.1 0.9 1.2 2.2 3.3 4.4
...
99 50 50 50 10.0 12.5 12.5 12.5 1.1 0.9 1.2 2.2 3.3 4.4
# the previous line was the last of the event
# now a new event is starting
#!OSCAR2013 full-evolution 100 50 50 50 it ix iy iz t x y z vx vy zx e p T
...
The shebang format is
#!OSCAR2013 hypersurface columns
The minimal set of columns is
t x y z : coordinates of fluid cell
vx vy vz : fluid flow velocity
e p T : energy density, pressure, temperature
dst dsx dsy dsz : fluid cell normal vector dsigma_mu
For example
#!OSCAR2013 hypersurface t x y z vx vy vz e p T dst dsx dsy dsz
5.0 -6.5 3.0 7.0 -1.0 0.5 2.0 1.0 1.0 1.0 2.0 3.0 4.0 5.0
...
The shebang format is
#!OSCAR2013 particles columns
The minimal set of columns is
ID : PDG particle ID
t x y z : spacetime vector
p0 px py pz : energy-momentum vector
For example
#!OSCAR2013 particles ID t x y z p0 px py pz
211 10.0 5.0 5.0 5.0 10.0 -3.0 -4.0 -5.0
...