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python plot normal distribution
...ot as plt
import numpy as np
import scipy.stats as stats
import math
mu = 0
variance = 1
sigma = math.sqrt(variance)
x = np.linspace(mu - 3*sigma, mu + 3*sigma, 100)
plt.plot(x, stats.norm.pdf(x, mu, sigma))
plt.show()
s...
[] and {} vs list() and dict(), which is better?
...s/dicts:
>>> from timeit import timeit
>>> timeit("[]")
0.040084982867934334
>>> timeit("list()")
0.17704233359267718
>>> timeit("{}")
0.033620194745424214
>>> timeit("dict()")
0.1821558326547077
and for non-empty:
>>> timeit("[1,2,3]")
0.243...
How to initialize all members of an array to the same value?
...
Unless that value is 0 (in which case you can omit some part of the initializer
and the corresponding elements will be initialized to 0), there's no easy way.
Don't overlook the obvious solution, though:
int myArray[10] = { 5, 5, 5, 5, 5, 5, 5,...
Accessing nested JavaScript objects and arays by string path
... // strip a leading dot
var a = s.split('.');
for (var i = 0, n = a.length; i < n; ++i) {
var k = a[i];
if (k in o) {
o = o[k];
} else {
return;
}
}
return o;
}
Usage::
Object.byString(someObj, 'part3[0].name');
...
PHP Foreach Pass by Reference: Last Element Duplicating? (Bug?)
...
170
After the first foreach loop, $item is still a reference to some value which is also being used ...
Flatten nested dictionaries, compressing keys
...t(items)
>>> flatten({'a': 1, 'c': {'a': 2, 'b': {'x': 5, 'y' : 10}}, 'd': [1, 2, 3]})
{'a': 1, 'c_a': 2, 'c_b_x': 5, 'd': [1, 2, 3], 'c_b_y': 10}
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VC DDE(Dynamic Data Exchange)与EXCEL连接 - C/C++ - 清泛网 - 专注C/C++及内核技术
...的通信方案。花了半天时间研究了下,做了个案例,VC6.0下调试通过,很开心。作为一个产品经理,为产品设计搭建好平台,有人的平台,有技术平台,一切目标为了高效的做好产品。
该C++控制台程序案例如下:
// smdata.cpp : ...
Can the Unix list command 'ls' output numerical chmod permissions?
...
it almost can ..
ls -l | awk '{k=0;for(i=0;i<=8;i++)k+=((substr($1,i+2,1)~/[rwx]/) \
*2^(8-i));if(k)printf("%0o ",k);print}'
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improv...
Google Maps: how to get country, state/province/region, city given a lat/long value?
...ld look like:
http://maps.googleapis.com/maps/api/geocode/json?latlng=40.714224,-73.961452&sensor=false
Response:
{
"status": "OK",
"results": [ {
"types": [ "street_address" ],
"formatted_address": "275-291 Bedford Ave, Brooklyn, NY 11211, USA",
"address_components": [ {
...
Warning: Null value is eliminated by an aggregate or other SET operation in Aqua Data Studio
...ult is display.
How to solve this problem?. How to change the null data to 0 when no data in the table?.
6 Answers
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