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Is there an R function for finding the index of an element in a vector?
...
The function match works on vectors :
x <- sample(1:10)
x
# [1] 4 5 9 3 8 1 6 10 7 2
match(c(4,8),x)
# [1] 1 5
match only returns the first encounter of a match, as you requested. It returns the position in the second argument of the values in the first argument.
Fo...
Add column with number of days between dates in DataFrame pandas
...'] - df['B']
In [14]: df
Out[14]:
A B C
one 2014-01-01 2014-02-28 -58 days
two 2014-02-03 2014-03-01 -26 days
Note: ensure you're using a new of pandas (e.g. 0.13.1), this may not work in older versions.
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What is the difference between ndarray and array in numpy?
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edited Sep 27 '18 at 14:40
nbro
10.9k1717 gold badges7676 silver badges140140 bronze badges
answered Ap...
UIView bottom border?
...
CALayer *bottomBorder = [CALayer layer];
bottomBorder.frame = CGRectMake(0.0f, 43.0f, toScrollView.frame.size.width, 1.0f);
bottomBorder.backgroundColor = [UIColor colorWithWhite:0.8f
alpha:1.0f].CGColor;
[toScrollView.layer addSublayer:bottomBor...
Git 工具 - 子模块(submodule)：一个仓库包含另一个仓库 - 开源 & Github -...
...or'...
remote: Counting objects: 11, done.
remote: Compressing objects: 100% (10/10), done.
remote: Total 11 (delta 0), reused 11 (delta 0)
Unpacking objects: 100% (11/11), done.
Checking connectivity... done.
默认情况下，子模块会将子项目放到一个与仓库同名的目录...
How to read/write a boolean when implementing the Parcelable interface?
...s how I'd do it...
writeToParcel:
dest.writeByte((byte) (myBoolean ? 1 : 0)); //if myBoolean == true, byte == 1
readFromParcel:
myBoolean = in.readByte() != 0; //myBoolean == true if byte != 0
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Remove characters from NSString?
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280
You could use:
NSString *stringWithoutSpaces = [myString
stringByReplacingOccurrencesOfStri...
Storing Image Data for offline web application (client-side storage database)
...e an offline web application using appcaching. I need to provide it about 10MB - 20MB of data that it will save (client-side) consisting mainly of PNG image files. The operation is as follows:
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Finding Number of Cores in Java
... |
edited Nov 17 '11 at 9:03
answered Jan 21 '11 at 13:58
d...
What is the maximum float in Python?
...ort sys
>>> sys.float_info
sys.floatinfo(max=1.7976931348623157e+308, max_exp=1024, max_10_exp=308, min=2.2
250738585072014e-308, min_exp=-1021, min_10_exp=-307, dig=15, mant_dig=53, epsil
on=2.2204460492503131e-16, radix=2, rounds=1)
Specifically, sys.float_info.max:
>>> sys.fl...