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Convert data.frame column format from character to factor
... Thanks! but I have another problem. I have the name of each column in an array of characters col_names[]. How can I use the above command (neither mydf$col_names[i] nor mydf[,col_names[i]] doesn't work.)
– Rasoul
Feb 12 '12 at 18:41
...
How can I get all constants of a type by reflection?
...t's an old code:
private FieldInfo[] GetConstants(System.Type type)
{
ArrayList constants = new ArrayList();
FieldInfo[] fieldInfos = type.GetFields(
// Gets all public and static fields
BindingFlags.Public | BindingFlags.Static |
// This tells it to get the field...
How to enumerate an enum with String type?
...od point right at the end about making each enum value is in the allValues array with a unit test. However, I can still see someone adding more elements, but not enforcing them in the unit test which still leaves us back at the beginning, not knowing for sure that all enum values are kept in allValu...
Why use double indirection? or Why use pointers to pointers?
...ters use references of references, while arr[a][b][c] is stored as a usual array in row major order.
– MCCCS
Jun 23 '18 at 9:50
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c++11 Return value optimization or move? [duplicate]
...the move operations in that example is to replace vector<Noisy> with array<Noisy,3>. That allows you to see moves in conjunction with a container of objects, but the objects are aggregated into the data type directly as values rather than hidden behind freestore allocations that allow S...
How to delete an item in a list if it exists?
...ith CPython, its quite likely most/all other Python implementations use an array to store lists internally. So unless they use a sophisticated data structure designed for efficient list re-sizing, they likely have the same performance characteristic.
A simple way to test this, compare the speed...
How to find memory leak in a C++ code/project?
...to free a single object. Use delete [] with square brackets to free a heap array. Don't do something like this:
char* one = new char;
delete [] one; // Wrong
char* many = new char [30];
delete many; // Wrong!
6
If the leak yet allowed - I'm usually seeking it with deleaker (check it here: htt...
Handling warning for possible multiple enumeration of IEnumerable
...YourMethod accepts an IReadOnlyCollection, unless you call .ToList() or .ToArray() on the argument. While it is important not to pass LinQ to SQL queries to your method, I think it is easier to make sure .ToListAsync() is called on all your queries at a few places than adding .ToList() to tons of ca...
What is a StackOverflowError?
...y primitive types and references are kept on the stack. All the big stuff (arrays and objects) is on the heap.
– jcsahnwaldt Reinstate Monica
Jan 23 '15 at 2:25
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Swift equivalent for MIN and MAX macros
...ore, if you want to get the min/max element of elements that are inside an Array, a Set, a Dictionary or any other sequence of Comparable elements, you can use the max() or the min() methods (see this Stack Overflow answer for more details).
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