Learned several split-and-combine functions
lapply : return a list;
sapply : simplified result of lapply
apply: apply functions on the matrix, directions (rows or columns) could be chosen. 126 more words
2 hours, 38 minutes ago
Quite some software engineers think that design patterns are some overly complicated, mythical, abstract things that bring no practical value to software development. This is unfortunate. 1,533 more words
10 hours, 31 minutes ago
Singleton is one of the simplest patterns to learn.
The objective of this pattern is maitain only one instance of a class.
Imagine this scenario: 111 more words
16 hours, 50 minutes ago
1, Q: How many objects can be made out of a singleton class?
2, Q: In what circumstances would you like to implement your application as a singleton class? 162 more words
2 days, 13 hours ago
A Data Developer
2 days, 23 hours ago
The R control syntax,
for loop and several usage of for loop
repeat, next, break
Some practice in ‘themes’ and ‘styles’. 69 more words
5 days, 5 hours ago
In this article I’ll write about the Iterator Design Pattern. This pattern is used to iterate over an aggregate object without exposing the underlying implementation of this object. 1,000 more words
6 days, 2 hours ago