performance measurements
Each table row shows performance measurements for this Python 2 program with a particular command-line input value N.
| N | CPU secs | Elapsed secs | Memory KB | Code B | ≈ CPU Load |
|---|---|---|---|---|---|
| 550 | 2.36 | 2.36 | 6,640 | 498 | 0% 0% 0% 0% 1% 100% 0% 0% |
Read the ↓ make, command line, and program output logs to see how this program was run.
Read spectral-norm benchmark to see what this program should do.
notes
spectral-norm Python 2 #6 program source code
# The Computer Language Benchmarks Game
# http://benchmarksgame.alioth.debian.org/
#
# Contributed by Sebastien Loisel
# Fixed by Isaac Gouy
# Sped up by Josh Goldfoot
# Dirtily sped up by Simon Descarpentries
# Used list comprehension by Vadim Zelenin
# 2to3
from math import sqrt
from sys import argv
def eval_A(i, j):
ij = i+j
return 1.0 / (ij * (ij + 1) / 2 + i + 1)
def eval_A_times_u(u):
local_eval_A = eval_A
return [ sum([ local_eval_A(i, j) * u_j
for j, u_j in enumerate(u)
]
)
for i in range(len(u))
]
def eval_At_times_u(u):
local_eval_A = eval_A
return [ sum([ local_eval_A(j, i) * u_j
for j, u_j in enumerate(u)
]
)
for i in range(len(u))
]
def eval_AtA_times_u(u):
return eval_At_times_u(eval_A_times_u(u))
def main():
n = int(argv[1])
u = [1] * n
local_eval_AtA_times_u = eval_AtA_times_u
for dummy in range(10):
v = local_eval_AtA_times_u(u)
u = local_eval_AtA_times_u(v)
vBv = vv = 0
for ue, ve in zip(u, v):
vBv += ue * ve
vv += ve * ve
print("%0.9f" % (sqrt(vBv/vv)))
main()
make, command-line, and program output logs
Fri, 30 Oct 2020 20:27:18 GMT COMMAND LINE: /usr/bin/python2 spectralnorm.python-6.python 550 PROGRAM OUTPUT: 1.274224125