大约有 36,010 项符合查询结果（耗时：0.0364秒） [XML]
Cleaning `Inf` values from an R dataframe
...
Option 1
Use the fact that a data.frame is a list of columns, then use do.call to recreate a data.frame.
do.call(data.frame,lapply(DT, function(x) replace(x, is.infinite(x),NA)))
Option 2 -- data.table
You could use data.table and set. This avoids some internal copying.
DT <- data.table(...
What's the difference between deadlock and livelock?
...eal-world example of
livelock occurs when two people meet
in a narrow corridor, and each tries
to be polite by moving aside to let
the other pass, but they end up
swaying from side to side without
making any progress because they both
repeatedly move the same way at the
same time.
Livelock is a risk...
How do the post increment (i++) and pre increment (++i) operators work in Java?
...
Does this help?
a = 5;
i=++a + ++a + a++; =>
i=6 + 7 + 7; (a=8)
a = 5;
i=a++ + ++a + ++a; =>
i=5 + 7 + 8; (a=8)
The main point is that ++a increments the value and immediately returns it.
a++ also increments the v...
Convert a Scala list to a tuple?
...
You can't do this in a typesafe way. Why? Because in general we can't know the length of a list until runtime. But the "length" of a tuple must be encoded in its type, and hence known at compile time. For example, (1,'a',true) has the ...
Pandas get topmost n records within each group
... answered Nov 19 '13 at 10:46
dorvakdorvak
6,47544 gold badges2828 silver badges4141 bronze badges
...
ArrayList initialization equivalent to array initialization [duplicate]
...
Why do people never mention correct import/include/require statement in their posts?
– Tomáš Zato - Reinstate Monica
Feb 9 '16 at 20:58
...
How can I multiply and divide using only bit shifting and adding?
...ting. If I recall correctly, modern processors, if pipelined properly, can do multiplication just about as fast as addition, by messing with the utilization of the ALUs (arithmetic units) in the processor.
share
|
...
“open/close” SqlConnection or keep open?
...
IMHO - he should'nt even do close. the dispose will do it.
– Royi Namir
Jan 7 '13 at 20:11
2
...
How can I set up an editor to work with Git on Windows?
I'm trying out Git on Windows . I got to the point of trying "git commit" and I got this error:
33 Answers
...
How do I show a Save As dialog in WPF?
... button, gather some data and then put it in a text file that the user can download to their machine. I can get the first half of this, but how do you prompt a user with a "Save As" dialog box? The file itself will be a simple text file.
...