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Why does direction of index matter in MongoDB?
... ascending the index might look something like this:
Row A B
1 1 1
2 2 6
3 2 7
4 3 4
5 3 5
6 3 6
7 5 1
A query for A ascending B descending will need to jump around the index out of order to return the rows and will be slower. For example it will return Row 1, 3, 2...
dplyr: “Error in n(): function should not be called directly”
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120
I presume you have dplyr and plyr loaded in the same session. dplyr is not plyr. ddply is not a...
How to iterate over associative arrays in Bash
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answered Jun 24 '10 at 19:31
Paused until further notice.Paused until further notice.
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Python Infinity - Any caveats?
... not get an inf value through usual arithmetic calculations:
>>> 2.0**2
4.0
>>> _**2
16.0
>>> _**2
256.0
>>> _**2
65536.0
>>> _**2
4294967296.0
>>> _**2
1.8446744073709552e+19
>>> _**2
3.4028236692093846e+38
>>> _**2
1.15792089...
Create Pandas DataFrame from a string
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A simple way to do this is to use StringIO.StringIO (python2) or io.StringIO (python3) and pass that to the pandas.read_csv function. E.g:
import sys
if sys.version_info[0] < 3:
from StringIO import StringIO
else:
from io import StringIO
import pandas as pd
TESTDATA = ...
Which is better, number(x) or parseFloat(x)?
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answered Dec 3 '12 at 2:13
Nathan WallNathan Wall
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How can I find out if I have Xcode commandline tools installed?
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162
/usr/bin/xcodebuild -version
will give you the xcode version, run it via Terminal command
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Nested rows with bootstrap grid system?
I want 1 larger image with 4 smaller images in a 2x2 format like this:
2 Answers
2
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Error: Jump to case label
...In the following code, if foo equals 1, everything is ok, but if it equals 2, we'll accidentally use the i variable which does exist but probably contains garbage.
switch(foo) {
case 1:
int i = 42; // i exists all the way to the end of the switch
dostuff(i);
break;
case 2:
dostu...
Algorithm to calculate the number of divisors of a given number
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27 Answers
27
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