大约有 40,000 项符合查询结果（耗时：0.0749秒） [XML]
How to select bottom most rows?
...
This and other answers work fine when you're working on smaller tables. I don't think it's worth ordering the entire table by a column when you are just interested in the bottom few rows.
– steadyfish
Oct 13 '14 at 16:09
...
Add legend to ggplot2 line plot
...range your data frame
library(reshape2)
dd = melt(dd_sub, id=c("fecha"))
All that's left is a simple ggplot command:
ggplot(dd) + geom_line(aes(x=fecha, y=value, colour=variable)) +
scale_colour_manual(values=c("red","green","blue"))
Example plot
...
Is there a way to create a function from a string with javascript?
...github.com/reduardo7/sjsClass
Example
Class.extend('newClassName', {
__constructor: function() {
// ...
}
});
var x = new newClassName();
// Next is TRUE
newClassName.name === 'newClassName'
share
...
Relative frequencies / proportions with dplyr
...
Try this:
mtcars %>%
group_by(am, gear) %>%
summarise(n = n()) %>%
mutate(freq = n / sum(n))
# am gear n freq
# 1 0 3 15 0.7894737
# 2 0 4 4 0.2105263
# 3 1 4 8 0.6153846
# 4 1 5 5 0.3846154
From the dplyr vigne...
Is it possible to use Java 8 for Android development?
...
java 8
Android supports all Java 7 language features and a subset of Java 8 language features that vary by platform version.
To check which features of java 8 are supported
Use Java 8 language features
We've decided to add support for Java 8 ...
How do I sort an NSMutableArray with custom objects in it?
...rrayUsingSelector:@selector(compare:)];
NSSortDescriptor (better)
or usually even better:
NSSortDescriptor *sortDescriptor;
sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"birthDate"
ascending:YES];
NSArray *sortedArray = [drinkDetails sortedAr...
What is the largest Safe UDP Packet Size on the Internet
...rmation that you may not have anticipated. A 512-byte UDP payload is generally considered to do that, although even that does not leave quite enough space for a maximum size IP header.
share
|
impr...
google chrome extension :: console.log() from background page?
If I call console.log('something'); from the popup page, or any script included off that it works fine.
11 Answers
...
Can an Android NFC phone act as an NFC tag?
... a simple old nfc tag? Is there some application I'm not thinking of? Usually, you'd want to emulate something like a transit card, access key, or credit card which would require a secure element (I think, but not sure).
s...
Any reason why scala does not explicitly support dependent types?
...here are path dependent types and I think it is possible to express almost all the features of such languages as Epigram or Agda in Scala, but I'm wondering why Scala does not support this more explicitly like it does very nicely in other areas (say, DSLs) ?
Anything I'm missing like "it is not ne...