大约有 500 项符合查询结果（耗时：0.0151秒） [XML]
Turning a Comma Separated string into individual rows
...r example LEFT(CAST(Data AS VARCHAR(MAX))....
– smoore4
Jul 15 '16 at 15:27
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show 1 more comment
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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...
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...
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...
Find a Pull Request on Github where a commit was originally created
... with the PR link if it exists.
For example, if the SHA is 52797a7a3b087231e4e391e11ea861569205aaf4 and the repo is https://github.com/glimmerjs/glimmer-vm , then go to https://github.com/glimmerjs/glimmer-vm/commit/52797a7a3b087231e4e391e11ea861569205aaf4
...
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...
How to convert list of tuples to multiple lists?
...end(y)
print(len(xs_), len(ys_))
t3 = time.time()
print('Using *zip:\t{:.8f}s'.format(t2 - t1))
print('Using append:\t{:.8f}s'.format(t3 - t2))
My Python Version:
Python 3.6.3 (default, Oct 24 2017, 12:18:40)
[GCC 4.2.1 Compatible Apple LLVM 8.1.0 (clang-802.0.42)] on darwin
Type "help", "copyr...
How to sparsely checkout only one single file from a git repository?
...to find out the hash-id (for example 3cdc61015724f9965575ba954c8cd4232c8b42e4) and then you simply type:
git checkout hash-id path-to-file
Here is an actual example:
git checkout 3cdc61015724f9965575ba954c8cd4232c8b42e4 /var/www/css/page.css
...
Why are Docker container images so large?
... /bin/sh -c yum -y install nano; yum -y clean 12.39 MB
3f2fed40e4b0 2 weeks ago /bin/sh -c #(nop) ADD file:cee1a4fcfcd00d18da 372.7 MB
fd241224e9cf 2 weeks ago /bin/sh -c #(nop) MAINTAINER Lokesh Mandvekar 0 B
511136ea3c5a 12 months ago ...