大约有 600 项符合查询结果（耗时：0.0121秒） [XML]
Clojure: reduce vs. apply
...e3)))
"Elapsed time: 5.263 msecs"
499500
user=> (time (apply + (range 1e4)))
"Elapsed time: 19.721 msecs"
49995000
user=> (time (reduce + (range 1e4)))
"Elapsed time: 1.409 msecs"
49995000
user=> (time (reduce + (range 1e5)))
"Elapsed time: 17.524 msecs"
4999950000
user=> (time (apply +...
How to delete a row by reference in data.table?
... is all i care about here. something like this:
DT = data.table(col1 = 1:1e6)
cols = paste0('col', 2:100)
for (col in cols){ DT[, (col) := 1:1e6] }
keep.idxs = sample(1e6, 9e5, FALSE) # keep 90% of entries
DT.subset = data.table(col1 = DT[['col1']][keep.idxs]) # this is the subsetted table
for (col...
Best way to serialize an NSData into a hexadeximal string
...96a6b6c6d6e6f707172737475767778797a7b7c7d7e7f808182838485868788898a8b8c8d8e8f909192939495969798999a9b9c9d9e9fa0a1a2a3a4a5a6a7a8a9aaabacadaeafb0b1b2b3b4b5b6b7b8b9babbbcbdbebfc0c1c2c3c4c5c6c7c8c9cacbcccdcecfd0d1d2d3d4d5d6d7d8d9dadbdcdddedfe0e1e2e3e4e5e6e7e8e9eaebecedeeeff0f1f2f3f4f5f6f7f8f9fafbfcfdfef...
Calculate RSA key fingerprint
...rotected.
Now, as others have said, type
$ ssh-add -l
1024 fd:bc:8a:81:58:8f:2c:78:86:a2:cf:02:40:7d:9d:3c you@yourhost (DSA)
fd:bc:... is the fingerprint you are after. If there are multiple keys, multiple lines will be printed, and the last line contains the fingerprint of the last loaded key.
...
Turning a Comma Separated string into individual rows
...r example LEFT(CAST(Data AS VARCHAR(MAX))....
– smoore4
Jul 15 '16 at 15:27
|
show 1 more comment
...
What is the purpose of setting a key in data.table?
...
@Arun, is DT[J(1e4:1e5)] really equivalent to DF[DF$x > 1e4 & DF$x < 1e5, ]? Could you point me to what J means? Also that search wouldn't return any rows since sample(1e4, 1e7, TRUE) does not include numbers above 1e4.
...
Ternary operator is twice as slow as an if-else block?
...00009b 39 56 04 cmp dword ptr [esi+4],edx
0000009e 7F E4 jg 00000084
30: for (int x = 0; x < iterations; x++)
000000a0 41 inc ecx
000000a1 3B 4D F0 cmp ecx,dword ptr [ebp-10h]
000000a4 7C...
How to get the current time in milliseconds from C in Linux?
...LTIME, &spec);
s = spec.tv_sec;
ms = round(spec.tv_nsec / 1.0e6); // Convert nanoseconds to milliseconds
if (ms > 999) {
s++;
ms = 0;
}
printf("Current time: %"PRIdMAX".%03ld seconds since the Epoch\n",
(intmax_t)s, ms);
}
If your goal is to...
Redirect STDERR / STDOUT of a process AFTER it's been started, using command line?
...d)...done.
[Thread debugging using libthread_db enabled]
[New Thread 0x7f3c8f5a66e0 (LWP 5636)]
Loaded symbols for /lib/libpthread.so.0
Reading symbols from /lib/ld-linux-x86-64.so.2...(no debugging symbols found)...done.
Loaded symbols for /lib64/ld-linux-x86-64.so.2
(no debugging symbols found)
0...
Is there a library function for Root mean square error (RMSE) in python?
...000, 0.254, 0.998] #your performance goes here
print("d is: " + str(["%.8f" % elem for elem in d]))
print("p is: " + str(["%.8f" % elem for elem in p]))
def rmse(predictions, targets):
return np.sqrt(((predictions - targets) ** 2).mean())
rmse_val = rmse(np.array(d), np.array(p))
print("rms...