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Convert a row of a data frame to vector
...eful if your row contains a factor. Here is an example:
df_1 = data.frame(V1 = factor(11:15),
V2 = 21:25)
df_1[1,] %>% as.numeric() # you expect 11 21 but it returns
[1] 1 21
Here is another example (by default data.frame() converts characters to factors)
df_2 = data.frame...
Choice between vector::resize() and vector::reserve()
... the only effect.
So it depends on what you want. If you want an array of 1000 default items, use resize(). If you want an array to which you expect to insert 1000 items and want to avoid a couple of allocations, use reserve().
EDIT: Blastfurnace's comment made me read the question again and reali...
How can I determine whether a 2D Point is within a Polygon?
...ine NO 0
#define YES 1
#define COLLINEAR 2
int areIntersecting(
float v1x1, float v1y1, float v1x2, float v1y2,
float v2x1, float v2y1, float v2x2, float v2y2
) {
float d1, d2;
float a1, a2, b1, b2, c1, c2;
// Convert vector 1 to a line (line 1) of infinite length.
// We wa...
How to check if all of the following items are in a list?
...
What if your lists contain duplicates like this:
v1 = ['s', 'h', 'e', 'e', 'p']
v2 = ['s', 's', 'h']
Sets do not contain duplicates. So, the following line returns True.
set(v2).issubset(v1)
To count for duplicates, you can use the code:
v1 = sorted(v1)
v2 = sorted(v2...
Google Maps: how to get country, state/province/region, city given a lat/long value?
...ata.results[0];
var county, city;
$.each(loc1, function(k1,v1) {
if (k1 == "address_components") {
for (var i = 0; i < v1.length; i++) {
for (k2 in v1[i]) {
if (k2 == "types") {
var types = v...
传感器组件 · App Inventor 2 中文网
... 属性
事件
方法
位置传感器
属性
事件
方法
磁场传感器
属性
事件
方法
NFC
属...
Version number comparison in Python
...to pad the sequences.
from itertools import izip_longest
def version_cmp(v1, v2):
parts1, parts2 = [map(int, v.split('.')) for v in [v1, v2]]
parts1, parts2 = zip(*izip_longest(parts1, parts2, fillvalue=0))
return cmp(parts1, parts2)
With lower versions, some map hackery is required....
用Javascript获取页面元素的位置（全） - 更多技术 - 清泛网 - 专注C/C++及内核技术
用Javascript获取页面元素的位置（全）制作网页的过程中，你有时候需要知道某个元素在网页上的确切位置。下面的教程总结了Javascript在网页定位方面的相关知识。一、网页的大小和...制作网页的过程中，你有时候需要知道某个...
Can I use assert on Android devices?
...od@0001
000372: 1501 037f |0003: const/high16 v1, #int 2130903040 // #7f03
000376: 6e20 0500 1200 |0005: invoke-virtual {v2, v1}, Lcom/example/asserttest/AssertActivity;.setContentView:(I)V // method@0005
00037c: 1250 ...
How to test equality of Swift enums with associated values
...ase (.none, .none):
return true
case let (.simple(v0), .simple(v1)):
return v0 == v1
case let (.advanced(x0, y0), .advanced(x1, y1)):
return x0 == x1 && y0 == y1
default:
return false
}
}
...