大约有 42,000 项符合查询结果（耗时：0.0460秒） [XML]
What is “entropy and information gain”?
...I assume entropy was mentioned in the context of building decision trees.
To illustrate, imagine the task of learning to classify first-names into male/female groups. That is given a list of names each labeled with either m or f, we want to learn a model that fits the data and can be used to predic...
Limitations of Intel Assembly Syntax Compared to AT&T [closed]
To me, Intel syntax is much easier to read. If I go traipsing through assembly forest concentrating only on Intel syntax, will I miss anything? Is there any reason I would want to switch to AT&T (outside of being able to read others' AT&T assembly)? My first clue is that gdb uses AT&T by default.
...
Differences between hard real-time, soft real-time, and firm real-time?
..., and the examples provided for hard and soft real-time systems make sense to me. But, there is no real explanation or example of a firm real-time system. According to the link above:
...
How to change a nullable column to not nullable in a Rails migration?
I created a date column in a previous migration and set it to be nullable. Now I want to change it to be not nullable. How do I go about doing this assuming there are null rows in that database? I'm ok with setting those columns to Time.now if they're currently null.
...
Why does Windows64 use a different calling convention from all other OSes on x86-64?
AMD has an ABI specification that describes the calling convention to use on x86-64. All OSes follow it, except for Windows which has it's own x86-64 calling convention. Why?
...
var self = this?
...lbacks for event handlers changes the scope of this from "My instance" to "Whatever just called the callback" . So my code looks like this
...
When would anyone use a union? Is it a remnant from the C-only days?
...++ text I go through introduces them (sometimes in passing), but they tend to give very few practical examples of why or where to use them. When would unions be useful in a modern (or even legacy) case? My only two guesses would be programming microprocessors when you have very limited space to work...
What is the difference between -viewWillAppear: and -viewDidAppear:?
...general, this is what I do:
1) ViewDidLoad - Whenever I'm adding controls to a view that should appear together with the view, right away, I put it in the ViewDidLoad method. Basically this method is called whenever the view was loaded into memory. So for example, if my view is a form with 3 labels...
Best Practices for Laravel 4 Helpers and Basic Functions?
I'm trying to understand the best place to put a global function in Laravel 4. For example, date formatting. I don't think making a facade is worth it as facades are too modular. I've read articles about creating a library folder and storing classes there but that also seems like a lot for a simple ...
Convert columns to string in Pandas
...
One way to convert to string is to use astype:
total_rows['ColumnID'] = total_rows['ColumnID'].astype(str)
However, perhaps you are looking for the to_json function, which will convert keys to valid json (and therefore your keys t...