大约有 5,475 项符合查询结果（耗时：0.0170秒） [XML]
Understanding exactly when a data.table is a reference to (vs a copy of) another data.table
...nspect(DT))
# @0000000003B7E2A0 19 VECSXP g0c7 [OBJ,NAM(2),ATT] (len=2, tl=100)
# @00000000040C2288 14 REALSXP g0c2 [NAM(2)] (len=2, tl=0) 1,2
# @00000000040C2250 14 REALSXP g0c2 [NAM(2)] (len=2, tl=0) 11,12
# ATTRIB: # ..snip..
.Internal(inspect(newDT)) # precisely the same object at this p...
What is the behavior of integer division?
... positive values they are the same
int integerDivisionResultPositive= 125/100;//= 1
double flooringResultPositive= floor(125.0/100.0);//=1.0
For negative value this is different
int integerDivisionResultNegative= -125/100;//=-1
double flooringResultNegative= floor(-125.0/100.0);//=-2.0
...
What is the most efficient way to create a dictionary of two pandas Dataframe columns?
... comparion (using Wouter's method)
In [6]: df = pd.DataFrame(randint(0,10,10000).reshape(5000,2),columns=list('AB'))
In [7]: %timeit dict(zip(df.A,df.B))
1000 loops, best of 3: 1.27 ms per loop
In [8]: %timeit pd.Series(df.A.values,index=df.B).to_dict()
1000 loops, best of 3: 987 us per loop
...
How do I auto size a UIScrollView to fit its content
...instance, you have just one subview which is an UIView with frame (50, 50, 100, 100). Your content size will be (0, 0, 150, 150), not (50, 50, 100, 100).
– Evgeny
Jul 23 '19 at 13:03
...
jQuery Tips and Tricks
...exists...
}
Writing your own selectors
$.extend($.expr[":"], {
over100pixels: function (e)
{
return $(e).height() > 100;
}
});
$(".box:over100pixels").click(function ()
{
alert("The element you clicked is over 100 pixels height");
});
...
NTFS performance and large volumes of files and directories
...tch the old.
To answer your question more directly: If you're looking at 100K entries, no worries. Go knock yourself out. If you're looking at tens of millions of entries, then either:
a) Make plans to sub-divide them into sub-folders (e.g., lets say you have 100M files. It's better to store them...
When to use std::forward to forward arguments?
...SBKerrek SB
415k7676 gold badges781781 silver badges10021002 bronze badges
...
What is RSS and VSZ in Linux memory management
... to 2500K of shared libraries, has 200K of stack/heap allocations of which 100K is actually in memory (rest is swapped or unused), and it has only actually loaded 1000K of the shared libraries and 400K of its own binary then:
RSS: 400K + 1000K + 100K = 1500K
VSZ: 500K + 2500K + 200K = 3200K
Since...
What are Runtime.getRuntime().totalMemory() and freeMemory()?
...dTotal(),
(float)getAllocatedTotal() / (float)getTotal() * 100,
getTotal(),
isBounded()? "bounded" : "unbounded",
isAtMaximumAllocation()? "maxed out" : "can grow",
getUnallocated()
);
out.printf("Used: %...
Iterating over a numpy array
...performance. It is a bit slower than a list comprehension.
X = np.zeros((100, 100, 100))
%timeit list([((i,j,k), X[i,j,k]) for i in range(X.shape[0]) for j in range(X.shape[1]) for k in range(X.shape[2])])
1 loop, best of 3: 376 ms per loop
%timeit list(np.ndenumerate(X))
1 loop, best of 3: 570 ...