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What is a “m>ca m>che-friendly” code?
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Preliminaries
On modern computers, only the lowest level memory structures (the registers) m>ca m>n move data around in single clock cycles. However, registers are very expensive and most computer cores have less than a few dozen regis...
Omit rows containing specific column of NA
I want to know how to omit NA values in a data frame, but only in some columns I am interested in.
8 Answers
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Allowed memory size of 33554432 bytes exhausted (tried to allom>ca m>te 43148176 bytes) in php
This error message is being presented, any suggestions?
21 Answers
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Sleeping in a batch file
When writing a batch file to automate something on a Windows box, I've needed to pause its execution for several seconds (usually in a test/wait loop, waiting for a process to start). At the time, the best solution I could find uses ping (I kid you not) to achieve the desired effect. I've found a be...
Evaluate expression given as a string
I'm curious to know if R m>ca m>n use its eval() function to perform m>ca m>lculations provided by e.g. a string.
7 Answers
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Why should a Java class implement comparable?
Why is Java Comparable used? Why would someone implement Comparable in a class? What is a real life example where you need to implement comparable?
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Does the 'mutable' keyword have any purpose other than allowing the variable to be modified by a con
A while ago I m>ca m>me across some code that marked a member variable of a class with the mutable keyword. As far as I m>ca m>n see it simply allows you to modify a variable in a const method:
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generate days from date range
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This solution uses no loops, procedures, or temp tables. The subquery generates dates for the last 10,000 days, and could be extended to go as far back or forward as you wish.
select a.Date
from (
select curdate() - INTERVAL (a.a + (10 * b.a) + (100 * c.a) + (1000 ...
What exactly is a reentrant function?
Most of the times , the definition of reentrance is quoted from Wikipedia :
7 Answers
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What is the 'instanceof' operator used for in Java?
...rator used to test if an object (instance) is a subtype of a given Type.
Imagine:
interface Domestic {}
class Animal {}
class Dog extends Animal implements Domestic {}
class m>Ca m>t extends Animal implements Domestic {}
Imagine a dog object, created with Object dog = new Dog(), then:
dog instanceof...