大约有 16,000 项符合查询结果（耗时：0.0440秒） [XML]
Automatically expanding an R factor into a collection of 1/0 indicator variables for every factor le
...
And if you want to convert all factor columns, you can use: model.matrix(~., data=iris)[,-1]
– user890739
Jan 5 '16 at 0:32
...
How to replace list item in best way
...oldValue = valueFieldValue.ToString();
string newValue = value.ToString();
int index = listofelements.IndexOf(oldValue);
if(index != -1)
listofelements[index] = newValue;
This asks only once for the index. Your approach uses Contains first which needs to loop all items(in the worst case), then...
Android: Bitmaps loaded from gallery are rotated in ImageView
When I load an image from the media gallery into a Bitmap, everything is working fine, except that pictures that were shot with the camera while holding the phone vertically, are rotated so that I always get a horizontal picture even though it appears vertical in the gallery.
Why is that and how can...
Unmangling the result of std::type_info::name
...tly working on some logging code that supposed to - among other things - print information about the calling function. This should be relatively easy, standard C++ has a type_info class. This contains the name of the typeid'd class/function/etc. but it's mangled. It's not very useful. I.e. typeid...
Is std::vector so much slower than plain arrays?
...y a whole bunch of things not associated with the test.
I would also take into account that you are not correctly initializing/Destroying the Pixel object in the UseArrray() method as neither constructor/destructor is not called (this may not be an issue for this simple class but anything slightly ...
Is there any async equivalent of Process.Start?
...n use the Exited event together with TaskCompletionSource:
static Task<int> RunProcessAsync(string fileName)
{
var tcs = new TaskCompletionSource<int>();
var process = new Process
{
StartInfo = { FileName = fileName },
EnableRaisingEvents = true
};
...
Python JSON serialize a Decimal object
...
Hmm, for me this converts Decimal objects to floats, which is not acceptable. Loss of precision when working with currency, for instance.
– Matthew Schinckel
Oct 22 '10 at 0:12
...
How to Customize a Progress Bar In Android
...nt;
private ClipDrawable mImageDrawable;
// a field in your class
private int mLevel = 0;
private int fromLevel = 0;
private int toLevel = 0;
public static final int MAX_LEVEL = 10000;
public static final int LEVEL_DIFF = 100;
public static final int DELAY = 30;
private Handler mUpHandler = new H...
Why is creating a Thread said to be expensive?
...kes its creation expensive? I'm taking the statement as true, but I'm just interested in mechanics of Thread creation in JVM.
...
static const vs #define
.... It also has the advantage that it has no type, so it can be used for any integer value without generating warnings.
Advantages of "const"s are that they can be scoped, and they can be used in situations where a pointer to an object needs to be passed.
I don't know exactly what you are getting at...