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Should I use a data.frame or a matrix?
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@Michal: Matrices aren't really more memory efficient:
m <- matrix(1:400000, 200000, 2)
d <- data.frame(m)
object.size(m)
# 1600200 bytes
object.size(d)
# 1600776 bytes
... unless you have a large number of columns:
m <- matrix(1:400000, 2, 200000)
d <- data.frame(m)
object.size(m)
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Illegal pattern character 'T' when parsing a date string to java.util.Date
...ISO_8601_24H_FULL_FORMAT = "yyyy-MM-dd'T'HH:mm:ss.SSSXXX";
/**
* 0001-01-01T00:00:00.000Z
*/
public static final Date BEGINNING_OF_TIME;
/**
* 292278994-08-17T07:12:55.807Z
*/
public static final Date END_OF_TIME;
static
{
UTC = TimeZone.getTime...
Casting vs using the 'as' keyword in the CLR
...System.Diagnostics;
using System.Linq;
class Test
{
const int Size = 30000000;
static void Main()
{
object[] values = new object[Size];
for (int i = 0; i < Size - 2; i += 3)
{
values[i] = null;
values[i + 1] = "x";
values[i...
How can I get the count of milliseconds since midnight for the current?
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Do you mean?
long millis = System.currentTimeMillis() % 1000;
BTW Windows doesn't allow timetravel to 1969
C:\> date
Enter the new date: (dd-mm-yy) 2/8/1969
The system cannot accept the date entered.
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Create a new database with MySQL Workbench
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answered Apr 1 '11 at 16:49
Zach RattnerZach Rattner
17.8k88 gold badges5252 silver badges7979 bronze badges
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Random number from a range in a Bash Script
I need to generate a random port number between 2000-65000 from a shell script. The problem is $RANDOM is a 15-bit number, so I'm stuck!
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What is the length of the access_token in Facebook OAuth2?
...requires an upper-bound on this. Please give a realistic upperbound. e.g. 1000 characters, 10,000 characters, 1,000,000,000 characters? Having no upper-bound is just unreasonable.
– Yahya Uddin
Feb 7 '17 at 14:36
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Whitespace Matching Regex - Java
... /* dummy empty string for homogeneity */
+ "\\u0009" // CHARACTER TABULATION
+ "\\u000A" // LINE FEED (LF)
+ "\\u000B" // LINE TABULATION
+ "\\u000C" // FORM FEED (FF)
+ "\\u00...
What purpose does a tag serve inside of a tag?
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answered Aug 18 '14 at 9:11
Qantas 94 HeavyQantas 94 Heavy
14.4k1616 gold badges6060 silver badges7777 bronze badges
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What's the fastest way to delete a large folder in Windows?
...S uses a 'Schlemeil the Painter' algorithm (joelonsoftware.com/articles/fog0000000319.html) anytime a dir or del is done
– warren
Oct 9 '08 at 11:36
37
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