是否有可能使用提升蓄能器引导? [英] Is it possible to use boost accumulators with vectors?
问题描述
我想用升压蓄电池来计算一个变量,是一个矢量的统计数据。有一个简单的方法来做到这一点。我认为这是不可能的使用最愚蠢的事情:
I wanted to use boost accumulators to calculate statistics of a variable that is a vector. Is there a simple way to do this. I think it's not possible to use the dumbest thing:
using namespace boost::accumulators;
//stuff...
accumulator_set<vector<double>, stats<tag::mean> > acc;
vector<double> some_vetor;
//stuff
some_vector = doStuff();
acc(some_vector);
也许这是显而易见的,但我想反正。 :P
maybe this is obvious, but I tried anyway. :P
我想要的是有一个累加器,将计算一个载体,其是许多矢量的分量的平均值。有一个简单的方法?
What I wanted was to have an accumulator that would calculate a vector which is the mean of the components of many vectors. Is there an easy way out?
编辑:
我不知道,如果我是彻底说清楚。我不希望这样的:
I don't know if I was thoroughly clear. I don't want this:
for_each(vec.begin(), vec.end(),acc);
此将计算给定矢量的项的平均值。我需要的是不同的。我有一个函数,将吐向量:
This would calculate the mean of the entries of a given vector. What I need is different. I have a function that will spit vectors:
vector<double> doSomething();
// this is a monte carlo simulation;
和我需要运行很多次,并计算出的矢量是指那些载体的:
And I need to run this many times and calculate the vectorial mean of those vectors:
for(int i = 0; i < numberOfMCSteps; i++){
vec = doSomething();
acc(vec);
}
cout << mean(acc);
和我想的意思(ACC)是一个矢量本身,其条目由[i]将累积向量的项[I]的装置。
And I want mean(acc) to be a vector itself, whose entry [i] would be the means of the entries [i] of the accumulated vectors.
有专门关于这升压的文档暗示,但没有明确。而且我有点哑。 :P
Theres a hint about this in the docs of Boost, but nothing explicit. And I'm a bit dumb. :P
推荐答案
我看着你的问题了一下,似乎我已经Boost.Accumulators为的std ::支持向量
。以下是我能够在<一个找到href=\"http://www.boost.org/doc/libs/1_45_0/doc/html/accumulators/user_s_guide.html#accumulators.user_s_guide.the_accumulators_framework.extending_the_accumulators_framework.operators_ex\">a用户指南的部分:
I've looked into your question a bit, and it seems to me that Boost.Accumulators already provides support for std::vector
. Here is what I could find in a section of the user's guide :
又如,其中数字
运营商子库是很有用的是
当类型不限定
使用它所需的运算符重载
对于一些统计计算。
例如,的std ::矢量&lt;&GT;
不超载的算术运算符,但
它可能是使用有用的std ::矢量&lt;&GT;
作为样品或变动内容类型。该
数值运算符子库定义
必要的运算符重载的
在提高::数字::运营商
名字空间,它被带进范围
通过用该累加器框架
使用指令。
Another example where the Numeric Operators Sub-Library is useful is when a type does not define the operator overloads required to use it for some statistical calculations. For instance,
std::vector<>
does not overload any arithmetic operators, yet it may be useful to usestd::vector<>
as a sample or variate type. The Numeric Operators Sub-Library defines the necessary operator overloads in theboost::numeric::operators
namespace, which is brought into scope by the Accumulators Framework with a using directive.
事实上,经过验证,文件升压/累加器/数字/功能/ vector.hpp
的确实的包含必要的运营商的天真解决方案的工作。
Indeed, after verification, the file boost/accumulators/numeric/functional/vector.hpp
does contain the necessary operators for the 'naive' solution to work.
我相信你应该尝试:
- 既包括
-
升压/累加器/数字/功能/ vector.hpp
之前的任何其他蓄能器头 -
升压/累加器/数字/ functional.hpp
在定义BOOST_NUMERIC_FUNCTIONAL_STD_VECTOR_SUPPORT
- Including either
boost/accumulators/numeric/functional/vector.hpp
before any other accumulators headerboost/accumulators/numeric/functional.hpp
while definingBOOST_NUMERIC_FUNCTIONAL_STD_VECTOR_SUPPORT
有只有一个最后的细节留给:执行将在运行时打破,因为最初的累积值是缺省构造的,并试图尺寸的 N 的向量添加到空载体时会产生断言。对于这一点,似乎应该初始化累加器(其中<青霉> N 的是在你的载体的元素数):
There's only one last detail left : execution will break at runtime because the initial accumulated value is default-constructed, and an assertion will occur when trying to add a vector of size n to an empty vector. For this, it seems you should initialize the accumulator with (where n is the number of elements in your vector) :
accumulator_set<std::vector<double>, stats<tag::mean> > acc(std::vector<double>(n));
我尝试以下code,
的意思是
给我大小为2的的std ::矢量
:int main() { accumulator_set<std::vector<double>, stats<tag::mean> > acc(std::vector<double>(2)); const std::vector<double> v1 = boost::assign::list_of(1.)(2.); const std::vector<double> v2 = boost::assign::list_of(2.)(3.); const std::vector<double> v3 = boost::assign::list_of(3.)(4.); acc(v1); acc(v2); acc(v3); const std::vector<double> &meanVector = mean(acc); }
我相信这是你想要的吗?
I believe this is what you wanted ?
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