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How to delete a row by reference in data.table?
...nce yet.
data.table can add and delete columns by reference since it over-allocates the vector of column pointers, as you know. The plan is to do something similar for rows and allow fast insert and delete. A row delete would use memmove in C to budge up the items (in each and every column) after t...
jQuery: checking if the value of a field is null (empty)
...ype]').val().length != 0){}
If you want to check if the element exist at all, you should do that before calling val:
var $d = $('#person_data[document_type]');
if ($d.length != 0) {
if ($d.val().length != 0 ) {...}
}
s...
How do you increase the max number of concurrent connections in Apache?
...ts 200
MinSpareThreads 25
MaxSpareThreads 75
ThreadsPerChild 25
First of all, whenever an apache is started, it will start 2 child processes which is determined by StartServers parameter. Then each process will start 25 threads determined by ThreadsPerChild parameter so this means 2 process can se...
Single Page Application: advantages and disadvantages [closed]
...pages.
The number of pages user downloads during visit to my web site?? really how many mails some reads when he/she opens his/her mail account. I read >50 at one go. now the structure of the mails is almost the same. if you will use a server side rendering scheme the server would then render it...
What are the mathematical/computational principles behind this game?
My kids have this fun game called Spot It! The game constraints (as best I can describe) are:
9 Answers
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What is the difference between `after_create` and `after_save` and when to use which?
... readers should note that, according to the docs, ActiveRecord's update_all does not invoke any callbacks, including after_*
– user2426679
Jan 10 at 19:34
add a comment
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Android Layout with ListView and Buttons
...
That's what I've basically been using, though I'm writing the layout in Java. The listView still extends over the buttons.
– Kleptine
Mar 5 '10 at 1:28
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Specifying and saving a figure with exact size in pixels
...):
plt.figure(figsize=(800/my_dpi, 800/my_dpi), dpi=my_dpi)
So you basically just divide the dimensions in inches by your DPI.
If you want to save a figure of a specific size, then it is a different matter. Screen DPIs are not so important anymore (unless you ask for a figure that won't fit in ...
Passing a list of kwargs?
... another function's kwargs. Consider this code: (newlines don't seem to be allowed in comments) def a(**kw): print(kw), and def b(**kw): a(kw). This code will generate an error because kwargs is actually a dictionary, and will be interpreted as a regular argument of the dict type. Which is why chang...
Where is the “Fold” LINQ Extension Method?
I found in MSDN's Linq samples a neat method called Fold() that I want to use. Their example:
2 Answers
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