D******4
发帖数: 47 | 1 Which allocator member function do standard containers use to acquire
storage for their elements in C++?
A. std::allocator<>::make(size_t)
B. std::allocator<>::new(size_t)
C. std::allocator<>::malloc(int)
D. std::allocator<>::allocate(size_t)
E. std::allocator<>::acquire(size_t)
我只知道D，allocate是allocator 的member function.
多谢 |
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g****g
发帖数: 1828 | 2 SGI Logo
vector
Category: containers Component type: type
Description
A vector is a Sequence that supports random access to elements, constant
time insertion and removal of elements at the end, and linear time insertion
and removal of elements at the beginning or in the middle. The number of
elements in a vector may vary dynamically; memory management is automatic.
Vector is the simplest of the STL container classes, and in many cases the
most efficient.
Example
vector V;
... 阅读全帖 |
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s*******e
发帖数: 257 | 3 有好几个帐号，401K, IRA, taxable, 529，还有taxable。如果每一个分别有一个
asset allocation，每个都要单独达到这个allocation，尤其vanguard还没有一个很方
便的"rebalance"的link。如果合起来有一个asset allocation，有的帐号又在不同的
公司。
请问关于这种情况有什么建议？有什么方法推荐吗？
还有一个问题是，最近关于asset allocation里面的large, mid, small的分配比较
疑惑，对于total stock的(66%, 27%, 7%)还有（40%，30%，30%），哪种比例比较好？
谢谢大家 |
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t****t
发帖数: 6806 | 4
the
it's most likely allocated on .bss (uninitialized)/.data (initialized)
section, which is indeed "allocated" before runtime, since it's not dynamic
allocation anyway. Link editor will "know" the address of each, but before
execution starts, dynamic loader will "allocate" all the memory required for
.bss, most likely in one go.
for non-POD (non-trivial ctor), the ctor is executed before main(). The
order in one compilation unit is always up-to-down, but order across
multiple compilation units... 阅读全帖 |
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w*******y
发帖数: 372 | 13 We know that using heap-allocated memory is slower than stack memory. Can
anyone tell me how much slower is the heap memory allocation? A numerical
analysis on a popular implementation would be terrific, e.g., linux. Another
stupid question: after memory allocation, the access to heap memory should
be as fast as to stack memory, right?
Thanks. |
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d******e
发帖数: 117 | 14 我的程序里用mmap预定了一大块内存区域，现在想在这个指定的内存区域里alloc/free
小的内存块，请问有没有现存的allocator实现这个功能？ |
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c**********e
发帖数: 2007 | 15 I want to dynamically allocate int Q[L+1][M+1]. I tried the following.
How to fix it?
int **Q = new int*[L+1]; // allocate the rows
for (i = 0; i < (L+1); i++) // now allocate the columns
*Q[i] = new int[M+1];
The error: cannot convert from 'int *' to 'int' |
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Y******u
发帖数: 1912 | 16 fundamental hedge fund usually doesn't need asset allocation. quant hedge
fund probably doesn't need traditional asset allocation model that you would
use in most asset managers
better stay in asset management if you want to have career in asset
allocation.
offer |
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l**********n
发帖数: 303 | 17 Hello, I am having trouble with unsufficient memory in SAS, does anyone know
how to allocate more memory in SAS? Thanks a lot!
Error: Unable to allocate sufficient memory: a request for 360113K bytes exceeded the 786430K available. Note that the deficit amount may not be the amount of memory needed for a successful run, since it does not reflect subsequent allocations by this or other processes. |
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V***o
发帖数: 678 | 18 Mutual funds in China cut their recommended equity weightings to 84.8% from
a record high in October while raising allocations to cash and bonds, as
expectations of inflation and further monetary tightening reduce risk
appetite, a monthly Reuters poll of fund managers showed.
Suggested equity weightings over the next three months fell from 88.9% last
month, while recommended allocations for bonds rose to 3.2% from a record
low of 2.4% in October, the poll of nine China-based funds showed. Sugges... 阅读全帖 |
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B******s
发帖数: 111 | 19 最近一个NSF grant被recommended，budget被砍掉10%左右，正在做budget revision。
有几个问题请大牛们指点：
1. 当初交proposal时，我和另一个co-PI（本校，非本院）credit allocation是70/30
. 请问这个allocation对funding管理有什么影响吗？ 是不是30%的budget被分到co-PI
的院由co-PI管理吗？ 还是所有budget都在一个帐户由PI统一管理？
2. re-budget的时候我跟Co-PI商量好了，我们第三年的summer salary有可能会被挪用
来支持一个GA（如果有合适的）。他也同意了。 如果funding被分到2个帐户，还能这
样操作吗？总觉得分出去的钱很难再要回来了。
3.如果我在项目期间跳槽，是不是只能带走funding的70%？ |
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K****D
发帖数: 30533 | 20 ☆─────────────────────────────────────☆
shangstud (某某某) 于 (Fri Oct 17 17:40:59 2008) 提到:
when I read the tread on not copying what Warren Buffet did, someone, might
be splendidchen? mentions that buy-and-hold is not the same as never sell
anything and that it is important to do asset allocation and rebalance.
I completely agree to that and I think it is ultimately important to do your
diversification, do you allocation, and do your rebalance.
From what I understand, the purpose of doing all |
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S**C
发帖数: 2964 | 21 Under the new allocation guidelines, Japanese stocks and foreign stocks will
each take up 25% of the fund’s holdings, up from 12% each previously. The
fund intends to put 35% of its money in domestic bonds, down from 60%, while
the ratio for overseas bonds will rise to 15% from 11%.
The previous allocation somehow did not add up to 100%. Anyway, it's a big
shift, 26% of $1.2T will go to equities, that's a little over $300B. |
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r****m
发帖数: 1204 | 22 Wealthfront, betterment, wisebanyan, etc. those robo-advisors provide good
and free AA advices, but they don't apply for individual's 401k AA
allocations, which could be a daunting task for someone without any
experience.
wealthminder and paulmerrian provide company-specific 401k advices (if your
company is on their lists).
There are also for-fee 401k allocation services, not many, though, you can
google them. |
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s******d
发帖数: 323 | 23 Van anybody help to see if I need to change my allocations. This year's
return so far is only 1.48%. Thanks!
Investment option
Allocation %
Stable Value
Minnesota Life General Account
Money Market
Advantus Money Market
General Bond
BlackRock Strategic Income Opps Instl
Columbia Limited Duration Credit R4
Templeton Global Bond A_________20%
Vanguard Interm-Term Bond Index Adm_________5%
Vanguard Long-Term Investment-Grade Adm
US Stock
Advantus S&P 500/Citigroup Growth
Advantus S... 阅读全帖 |
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l*****g
发帖数: 685 | 24 comfort, 看来你碰到了一个爱考茴香的茴有几种写法的孔乙己式牛人
有个alloca function, 可以用来在dynamically allocate memory in stack. 但是这
个function,
不是C++ standard, 不是所有compiler都support, 而且只能allocate很少量memory,
否则很容易
causes stack overflow.
总之, 用alloca不是good practice. 需要用alloca的case, 都可以用一个fixed or
dynamic array来解决 |
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g******g
发帖数: 35 | 25 请提供你的联系方式： name and e-mail address
A HIGH-PERFORMANCE SCHEDULER FOR JOIN
QUERIES EXECUTION OVER GRID-AWARE
ARCHITECTURES
Abstract
A Grid is a collection of computing resources that share and perform tasks.
Performance optimization can be achieved by
exploiting the Grid power utilities; i.e. multi-processing, multi-
programming, abstract task execution. This paper explores
the management of distributed relational databases over Grid infrastructures
for the execution of J − join queries. Our... 阅读全帖 |
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m*******i
发帖数: 370 | 27 “Effective Friday, July 31, 2015 it has been necessary to stop
authorizations in response to requests for China Employment Second
preference cases for the remainder of FY-2015. This action was necessary
because the FY-2015 annual limit for this category has been reached. Numbers
will once again be available for this Employment category beginning October
1, 2015 under their FY-2016 annual numerical limitation. Visa requests for
the remaining applications that are not allocated visa numbers will b... 阅读全帖 |
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o****i
发帖数: 1706 | 28 程序运行正常，可是在测memery leak的时候报上面那个错，具体错误消息如下：
==25663== Conditional jump or move depends on uninitialised value(s)
==25663== at 0x400C9F: add_edge (graph.c:59)
==25663== by 0x40071A: main (main.c:13)
==25663== Uninitialised value was created by a heap allocation
==25663== at 0x4A0515D: malloc (vg_replace_malloc.c:195)
==25663== by 0x400A80: add_vertex (graph.c:22)
==25663== by 0x400DF8: add_edge (graph.c:84)
==25663== by 0x40071A: main (main.c:13)
我的程序用链接表构建一个无向图来解决TSP的.
graph.c:2... 阅读全帖 |
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R*******N
发帖数: 7494 | 29 为什么alloc之后其它process就不能访问?
CPU执行MOV指令之前去哪查被访问memory是否被allocate? |
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t*****g
发帖数: 1275 | 30 Dynamic array on stack is allocated using calculated size instead of 'pre-
calculated' or 'hard-coded' size; The allocation is not different than
moving the stack pointer though. The following assembly code may show you
how it works (solaris on x86)
...
leal -0x8(%ebp),%eax ; pipe scanf output to this address
...
call -0x23d ; call scanf
movl -0x8(%ebp),%eax ; obain variable 'n' and save it to %eax
...
subl %eax,%esp ; grow the stack pointer |
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k**f
发帖数: 372 | 31 Your question is not clear.
You may want to explain what is "automatic space allocation", probably using
the example of another language.
In your code snippet
int i, a[100];
the compiler will allocation space on the stack for an integer i, and space
for integer array a of 100 integers. |
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f******y
发帖数: 2971 | 32 since there are containers like vector, we can allocate memories at run time
much easier and do not need
to worry about the memory leak. It seems to me the "new","alloc" operators
are no longer necessary in
C++. At least, the programmers do not need to handle them directly at all. But
why they are still there? |
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E*****7
发帖数: 128 | 33 For objects that use dynamic memory, new operation must be performed in the constructor to allocate the memory. An object used in containers such as vector must have a constructor either written by the programmer to initialize it or a default constructor generated by the compiler by default. If your program always deals built-in type such as integer in vector where the constructor of int generated by the compiler by default always does its job, you need not worry about dynamic allocation at |
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c******g
发帖数: 63 | 34 两种情况，一个是global static，一个是local static。
有一点应该没啥疑问，就是这两种static variable的memory allocation是before the
program starts的（我的理解是进入main()函数之前）。但是经常有参考资料中看到
说是“at the compile time”--这就不太懂了，我把一个.cpp文件compile一下就把
memory给allocate了？这明显不可能嘛。
第二个问题是：它们到底是啥时候initialize的？我觉得global的static肯定是在到了
declare这个变量的那一句时initialize的，是在进入main()函数前。
那local的呢（在一个function里的）？究竟是在整个程序start之前initialize，还是
第一次访问那个函数，进入函数后到了declare这个变量的那一句时才initialize？
请诸位大虾给予详细批评指正！多谢！ |
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y***r
发帖数: 1845 | 36 不用cray pointer也可以，可以使用libU77中的MALLOC和FREE，可惜不是所有系统都
支持。但假如自己用C做一个EXTENSION，就可以了。
下面的程序的编译方法:
cc -c alloc.c
f77 memtest.f alloc.o
>>>>>>> memtest.f <<<<<<<<<<<
implicit none
integer*4 n, i
integer*4 addr
integer*4 offset
real*8 work(1)
C common /works/ work
n = 10
call cmalloc(N*N, 8, 0, work, addr, offset)
call test(N, WORK(offset+1))
call cfree(addr)
end
C
subroutine test(N,R)
implicit none
integer*4 |
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s******y
发帖数: 289 | 37 我还是 fresh Stat PhD 马上毕业。主要做的是 Empirical Modeling 和 Monte Carlo
Simulation。
看了版上的建议，似乎HF和IB对没GC没H1b的人很危险，所以投了一些边缘公司，不是
quant的职位。
刚接到个联系，西部的小mutual fund。职位主要是做 Asset Allocation，google随便
了解了一下，似乎和 Empirical Modeling 以及 Simulation, SDE 等没什么关系，也
不需要太高的编程。去的话，PhD所专的这写东西，就几乎不怎么用了，是么？
请问这个Asset Allocation方向做下去，以后前途如何呢？以后跳到花街机会多么？ |
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P********e
发帖数: 2610 | 38
int **Q = new int*[L+1]; // allocate the rows
for (i = 0; i < (L+1); i++) // now allocate the columns
Q[i] = new int[M+1]; |
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k**k
发帖数: 61 | 39 自己做这行但资历不算深，对业界的做法有些不太明白的地方，像请教一下有经验的诸
位.
I'll outline what I have found and questions I have. Hope to get some
insightful thoughts from people. From what I can see, there are four major
ways to do strategic asset allocation:
1. Mean-variance + efficient frontier
Problem with MV is it is static, one period, results unstable and counter-
intuitive sometimes. Improvements include using Monte Carlo to do multi-
period and factor in dynamic asset allocation over time, also to incorporate
fat-tail in |
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m***t
发帖数: 21 | 40 我是新手，想请教一下大家一般在做Asset allocation的时候
比如用mean variance的方法
return和variance matrix是怎么获得的
return可以用1m或者1y的expected return？
variance matrix用相同时间长度的time average？
如果是这样的如何取这个时间的跨度？如何保证estimation error很小
mean variance貌似对error很sensitive
但是这样optimize出来的asset allocation对future的prediction应该不是很好吧
或者这个方法是要和factor model之类的prediction结合使用？
谢谢大家了。
incorporate
. |
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k**k
发帖数: 61 | 41 When you say alpha/single modeling, it sounds like something related to
identifying opportunities within each asset classes or individual portfolio,
e.g. stock selection model. However, such work is more related to tactical
allocation than strategic from what I can see, which is not really what one
should considered when dealing with strategic allocation. Am I correct?
uncertainties. |
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l**********t
发帖数: 5754 | 42 For multi-period strategic allocation, MVO/efficient frontier may be
suboptimal/irrelevant.
Say you allocate among asset classes for a DB plan over 20 years, it is
much natural to frame the problem in
expected utility framework(based on surplus deficit) than MVO. You may find
more info from articles on portfolio
choice, life cycle consumption model, and asset liability management.
incorporate
. |
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发帖数: 1 | 43 听人说LA下个月就有破鞋的新卡宴试驾了, 不知道怎么样.
有人订allocation么? 订的时候能谈个5% off么? |
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s******d
发帖数: 323 | 44 ☆─────────────────────────────────────☆
fbb (manta) 于 (Sat Sep 8 16:10:40 2007) 提到:
Welcome to read the original post in my investing blog:
http://iffs.blogspot.com/2007/09/asset-allocation-target-plan.html
☆─────────────────────────────────────☆
tonys (基因决定人生) 于 (Sat Sep 8 20:08:45 2007) 提到:
what is your international small fund？
DLS？
☆─────────────────────────────────────☆
fbb (manta) 于 (Sat Sep 8 22:01:39 2007) 提到:
I use VINEX (Vanguard international explorer) in the 401(k). |
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t***n
发帖数: 546 | 45 a piece if paper 不行吧。要balance好US/international stock，bond，large/med/
small cap，而且每支基金都有点blender。还有，这些基金散布在几个broker/IRA账户
里面，所以这里也有一个constrain，就是不能无限制的买卖任何一支基金。
所以最好就是做一个有constrain的linear regression，得出在目前状况下趋近目标
allocation的最优解。
to
index |
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p********r
发帖数: 1980 | 46 Although US stock markets are at all-time high at the moment, when Big Ben
indicated that FED will stop QE soon, from May 22 to June 24, the S&P 500
lost 5.6%, MSCI EAFE lost 10.1%, MSCI Emerging fell 15.3%, the Dow Jones/UBS
Commodity index fell 4.5%, the U.S. 10-year T-Note fell 4.4%, and the
Barclays U.S. TIPS index fell 7.1%, the J.P. Morgan Emerging Debt Global
index fell 10.8%, the German 10-year Bund fell 5.2%, the UK 10-year Gilt
fell 3.4%, and the Australian 10-year bond fell 6.5%.
FED ... 阅读全帖 |
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D*****t
发帖数: 558 | 47 55% stock, 45% bond.
of stocks, 70% US, 30% foreign (of which, 45% EM)
of bonds, 30% TIPS, 60% short term investment grade, <10% high yield
i don't plan to do anything unless market moves and my allocation is off
target by at least 5%, then i will rebalance.
i also have a negligible position in gold stocks, which i started adding
since May, just for the fun of it. |
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E******w
发帖数: 2616 | 48 A simple answer is "fees". Usually maintenance fees are charged when you
hold whatever fund in the 401K account. The fees can be higher than what
they show in the fund perspective. Typical fee is 1~2% per year, some fancy
funds have over 3% charge per year. Note that this is not 3% of your profit,
it is 3% of your total fund value. For a rough calculation, if you hold the
fund for 10 years and the stock price does not change, your account will
lose about 20%. Now, if you do not know how to trade... 阅读全帖 |
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H*****1
发帖数: 4815 | 49 How do they collect fees without showing it on the statement? Do they sell
some stocks and re-allocate whatever left in the pool?
fancy
profit,
the
to |
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J******d
发帖数: 287 | 50 If I want to loan the money out next year for down payment of our primary
house purchase. That's mean I really want the money to grow fast. How should
I allocate the share?
Thank you so much!//bow
Bond
Fidelity Advisor Government Income T
Fidelity Advisor Intermediate Bond T
Fidelity Advisor Strategic Income T
Fidelity Advisor Total
Equity
Fidelity Advisor Balanced T
Fidelity Advisor Dividend Growth T
Fidelity Advisor Equity Growth T
Fidelity Advisor Equity Income T
Fidelity Advisor Freedom 2005... 阅读全帖 |
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