internals

One of the basic data types in R is factors. In my experience factors are basically a pain and I never use them. I always convert to characters. I feel oddly like I'm missing something. Are there some important examples of functions that use factors as grouping variables where the factor data type becomes necessary? Are there specific circumstances when I should be using factors? Vince You should use factors. Yes they can be a pain, but my theory is that 90% of why they're a pain is because in read.table and read.csv , the argument stringsAsFactors = TRUE by default (and most users miss this

I'm certainly missing some fundamental point about the injector, but I fail to understand why exactly this angular.module('app').config(function ($provide) { ... }); and this angular.module('app').config(function ($injector) { $injector.invoke(function ($provide) { ... }); }); work as intended, while this app.run(function($provide) { ... }); will throw Error: [$injector:unpr] Unknown provider: $provideProvider <- $provide As follows from the above, config has some special relationship with providers, while run deals with instances, yet I'm unsure about the thing that makes config blocks so

Been browsing through .NET source code of .NET Framework Reference Source , just for fun of it. And found something I don't understand. There is a Int32.cs file with C# code for Int32 type. And somehow that seems strange to me. How does the C# compiler compile code for Int32 type? public struct Int32: IComparable, IFormattable, IConvertible { internal int m_value; // ... } But isn't this illegal in C#? If int is only an alias for Int32 , it should fail to compile with Error CS0523 : Struct member 'struct2 field' of type 'struct1' causes a cycle in the struct layout. Is there some magic in the

I'm playing around with Ruby's .object_id and noticed that, in several sequential sessions of irb, I get these identical results: false.object_id // 0 true.object_id // 2 nil.object_id // 4 100.object_id // 201 In fact, every integer's object_id seems to be ((value * 2) + 1). On the other hand, a given string's object_id is never the same after exiting and re-running irb. This raises several questions for me: Is there a known scheme by which certain object_id s are determined? Are others basically random? The ids for true, false, and nil, aren't sequential. Is there a way to ask what object is

Could you please explain what the practical usage is for the internal keyword in C#? I know that the internal modifier limits access to the current assembly, but when and in which circumstance should I use it? Ash Utility or helper classes/methods that you would like to access from many other classes within the same assembly, but that you want to ensure code in other assemblies can't access. From MSDN (via archive.org): A common use of internal access is in component-based development because it enables a group of components to cooperate in a private manner without being exposed to the rest of