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Grouping functions (tapply, by, aggregate) and the *apply family
Whenever I want to do something "map"py in R, I usually try to use a function in the apply family.
10 Answers
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Change the Right Margin of a View Programmatically?
...
Use This function to set all Type of margins
public void setViewMargins(Context con, ViewGroup.LayoutParams params,
int left, int top , int right, int bottom, View view) {
final float scale = con.getResources(...
App Inventor 2 图标字体：2000 多个 Material 图标，文字与图标混排 · App Inventor 2 中文网
... 小写的英文单词本身就是图标名，会变图标
123、360、4k、5g
图标
这些数字和数字字母组合也是图标名
最后两行是混排最容易踩的坑，下面的场景三、场景六专门讲怎么避开。
场景一：带文...
Amazon S3 boto - how to create a folder?
... folders or directories in S3. You can create file names like "abc/xys/uvw/123.jpg", which many S3 access tools like S3Fox show like a directory structure, but it's actually just a single file in a bucket.
share
|
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How to map with index in Ruby?
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Here are two more options for 1.8.6 (or 1.9) without using enumerator:
# Fun with functional
arr = ('a'..'g').to_a
arr.zip( (2..(arr.length+2)).to_a )
#=> [["a", 2], ["b", 3], ["c", 4], ["d", 5], ["e", 6], ["f", 7], ["g", 8]]
# The simplest
n = 1
arr.map{ |c| [c, n+=1 ] }
#=> [["a", 2], ["b...
How can I iterate over an enum?
...b = 220,
c = -1
};
static const Type All[] = { a, b, c };
}
void fun( const MyEnum::Type e )
{
std::cout << e << std::endl;
}
int main()
{
// all
for ( const auto e : MyEnum::All )
fun( e );
// some
for ( const auto e : { MyEnum::a, MyEnum::b } )
fun( e );
...
How do I split a string on a delimiter in Bash?
...ring an array and implicitly "loop" over the delimited elements, calling a function on each:
myPubliMail() {
printf "Seq: %6d: Sending mail to '%s'..." $1 "$2"
# mail -s "This is not a spam..." "$2" </path/to/body
printf "\e[3D, done.\n"
}
mapfile < <(printf "%s\0" "$IN") -td \...
Meaning of epsilon argument of assertEquals for double values
...nal double DELTA = 1e-15;
@Test
public void testDelta(){
assertEquals(123.456, 123.456, DELTA);
}
If you're using hamcrest assertions, you can just use the standard equalTo() with two doubles (it doesn't use a delta). However if you want a delta, you can just use closeTo() (see javadoc), e.g....
SQLAlchemy IN clause
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How about
session.query(MyUserClass).filter(MyUserClass.id.in_((123,456))).all()
edit: Without the ORM, it would be
session.execute(
select(
[MyUserTable.c.id, MyUserTable.c.name],
MyUserTable.c.id.in_((123, 456))
)
).fetchall()
select() takes two parameters...
Truncate number to two decimal places without rounding
...2.55
2.99999 => 2.99
4.27 => 4.27
15.7784514 => 15.77
123.5999 => 123.59
0.000000199 => 1.99 *
* As mentioned in the note, that's due to javascript implicit conversion into exponential for "1.99e-7"
And for some other values of n:
15.001097 => 15.0010 (n=4)
0.00...