大约有 35,487 项符合查询结果（耗时：0.0479秒） [XML]
Pass column name in data.table using variable [duplicate]
...list(x, v))
DT[ , eval(temp)]
# x v
# 1: b 1.52566586
# 2: b 0.66057253
# 3: b -1.29654641
# 4: a -1.71998260
# 5: a 0.03159933
share
|
improve this answer
|
...
Interpret XMP-Metadata in ALAssetRepresentation
...
+500
ALAssetRepresentation* representation = [[self assetAtIndex:index] defaultRepresentation];
// Create a buffer to hold the data for t...
What is &&& operation in C
...
Luchian GrigoreLuchian Grigore
229k5050 gold badges409409 silver badges577577 bronze badges
...
matplotlib: colorbars and its text labels
...bar(heatmap)
cbar.ax.get_yaxis().set_ticks([])
for j, lab in enumerate(['$0$','$1$','$2$','$>3$']):
cbar.ax.text(.5, (2 * j + 1) / 8.0, lab, ha='center', va='center')
cbar.ax.get_yaxis().labelpad = 15
cbar.ax.set_ylabel('# of contacts', rotation=270)
# put the major ticks at the middle of ...
Select Pandas rows based on list index
...
ayhan
51.5k1010 gold badges128128 silver badges155155 bronze badges
answered Oct 3 '13 at 9:43
Woody PrideWoody P...
Why aren't my ball (objects) shrinking/disappearing?
....
First, in your definition:
var shrink = function(p) {
for (var i = 0; i < 100; i++) {
p.radius -= 1;
}
function asplode(p) {
setInterval(shrink(p),100);
balls.splice(p, 1);
}
}
asplode is local to the scope inside shrink and therefore not accessible...
C++ HICON与HBITMAP相互转换 - C/C++ - 清泛网 - 专注C/C++及内核技术
...map(::GetDC(NULL),
bmp.bmWidth, bmp.bmHeight);
ICONINFO ii = {0};
ii.fIcon = TRUE;
ii.hbmColor = bitmap;
ii.hbmMask = hbmMask;
HICON hIcon = ::CreateIconIndirect(&ii);//一旦不再需要，注意用DestroyIcon函数释放占用的内存及资源
::DeleteObjec...
C语言判断文件是否存在 - C/C++ - 清泛网 - 专注C/C++及内核技术
...io.h，原型：int access(const char *filename, int amode);amode参数为0时表示检查文件的存在性，如果文件存...用函数access，头文件是io.h，原型：
int access(const char *filename, int amode);
amode参数为0时表示检查文件的存在性，如果文件存在，返...
STL：accumulate与自定义数据类型 - C/C++ - 清泛网 - 专注C/C++及内核技术
...器中C++内置数据类型，例如：
#include <numeric>
int arr[]={10,20,30,40,50};
vector<int> va(&arr[0],&arr[5]);
int sum=accumulate(va.begin(),va.end(),0); //sum = 150
但是对于自定义数据类型，我们就需要自己动手写一个类来实现自定义数据的处理，然后...
libcurl网络连接使用tcp/ip - C/C++ - 清泛网 - 专注C/C++及内核技术
...url_easy_init();
if(curl) {
curl_easy_setopt(curl, CURLOPT_URL, "127.0.0.1");
curl_easy_setopt(curl, CURLOPT_PORT, 7102);
/* Do not do the transfer - only connect to host */
curl_easy_setopt(curl, CURLOPT_CONNECT_ONLY, 1L);
res = curl_easy_perform(curl);
if(CURLE_OK != r...