Lothar.brendel: new

2026-07-20T13:51:18Z

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The script can be useful e.g. when plotting data from the dbl-files on the fly. It reads 1D or 2D dbl-files from a <code>data</code>-directory and writes an ASCII table to stdout. More than one dbl-file (from the same grid) can be specified as arguments, producing a table with more than two columns.

The first argument is a "selector" specifying the location of the cut in the 2D case: ''ix1''<code>,</code> or just ''ix1'' yields a cut with fixed \(x_1\)-coordinate, while <code>,</code>''ix2'' produces one with fixed \(x_2\)-coordinate. The integers ''ix1'' and ''ix2'', respectively, denote the corresponding cell-number. (In the 1D case, the selector can be any character.)

<syntaxhighlight lang="python" copy>
#!/usr/bin/env python3

# L.B. 2026

import os
from sys import argv,stdout,stderr
import numpy as np

if len(argv) < 3:
print(f"usage: {os.path.basename(argv[0])} <selector> <dbl-file1> ...",file=stderr)
exit(1)

sel = argv[1].split(',')
dbl_fn = argv[2]
dbl_dir = os.path.dirname(dbl_fn)
if not dbl_dir:
dbl_dir="."
grid_fn = dbl_dir+"/grid.out"
time_fn = dbl_dir+"/dbl.out"

# parse "dbl.out" for time
t = {}
with open(time_fn) as time:
for line in time:
line = line.split()
t[int(line[0])] = float(line[1])

# pre-parse "grid.out"
with open(grid_fn) as grid:
dims = 0
shape = []
skip = []
for k,line in enumerate(grid):
if line[0] == "#":
if "DIMENSIONS" in line:
dims = int(line.split()[-1])
elif line[0] in "0123456789":
line = line.split()
if len(line) == 1 and line[0] != "1":
skip.append(k+1)
shape.append(int(line[0]))

# read grid from "grid.out"
pos = []
for skip,n in zip(skip,shape):
axis = np.loadtxt(grid_fn,skiprows=skip,max_rows=n)
pos.append(axis[:,1:].mean(1))

# read data file(s)
for dbl_fn in argv[2:]:

data = np.fromfile(dbl_fn,dtype="<f8").reshape(list(reversed(shape))).transpose()

it = int(dbl_fn.split('.')[-2])
header = f"# {os.path.basename(dbl_fn)}\n# t = {t[it]}\n"

if dims==1:
data = np.vstack((pos[0],data)).transpose()
elif dims==2:
if len(sel)==1 or sel[1]=="": # f(y), x fixed
ix1 = int(sel[0])
header += f"# x1 = {pos[0][ix1]}"
data = np.vstack((pos[1],data[ix1])).transpose()
else:
ix2 = int(sel[1])
header += f"# x2 = {pos[1][ix2]}"
data = np.vstack((pos[0],data[:,ix2])).transpose()
else:
print(f"{argv[0]}: {dbl_fn} is on a {dims}D grid, can only handle 1D and 2D.",file=stderr)
exit(1)

print(header)
np.savetxt(stdout,data,delimiter='\t')
print()
</syntaxhighlight>

Dbl-dump - Revision history

Lothar.brendel: new