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  • In PHP: How to call a $variable inside one function that was defined previously inside another funct

    - by Sam
    I'm just starting with Object Oriented PHP and I have the following issue: I have a class that contains a function that contains a certain script. I need to call a variable located in that script within another function further down the same class. For example: class helloWorld { function sayHello() { echo "Hello"; $var = "World"; } function sayWorld() { echo $var; } } in the above example I want to call $var which is a variable that was defined inside a previous function. This doesn't work though, so how can I do this?

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  • Bad performance function in PHP. With large files memory blows up! How can I refactor?

    - by André
    Hi I have a function that strips out lines from files. I'm handling with large files(more than 100Mb). I have the PHP Memory with 256MB but the function that handles with the strip out of lines blows up with a 100MB CSV File. What the function must do is this: Originally I have the CSV like: Copyright (c) 2007 MaxMind LLC. All Rights Reserved. locId,country,region,city,postalCode,latitude,longitude,metroCode,areaCode 1,"O1","","","",0.0000,0.0000,, 2,"AP","","","",35.0000,105.0000,, 3,"EU","","","",47.0000,8.0000,, 4,"AD","","","",42.5000,1.5000,, 5,"AE","","","",24.0000,54.0000,, 6,"AF","","","",33.0000,65.0000,, 7,"AG","","","",17.0500,-61.8000,, 8,"AI","","","",18.2500,-63.1667,, 9,"AL","","","",41.0000,20.0000,, When I pass the CSV file to this function I got: locId,country,region,city,postalCode,latitude,longitude,metroCode,areaCode 1,"O1","","","",0.0000,0.0000,, 2,"AP","","","",35.0000,105.0000,, 3,"EU","","","",47.0000,8.0000,, 4,"AD","","","",42.5000,1.5000,, 5,"AE","","","",24.0000,54.0000,, 6,"AF","","","",33.0000,65.0000,, 7,"AG","","","",17.0500,-61.8000,, 8,"AI","","","",18.2500,-63.1667,, 9,"AL","","","",41.0000,20.0000,, It only strips out the first line, nothing more. The problem is the performance of this function with large files, it blows up the memory. The function is: public function deleteLine($line_no, $csvFileName) { // this function strips a specific line from a file // if a line is stripped, functions returns True else false // // e.g. // deleteLine(-1, xyz.csv); // strip last line // deleteLine(1, xyz.csv); // strip first line // Assigna o nome do ficheiro $filename = $csvFileName; $strip_return=FALSE; $data=file($filename); $pipe=fopen($filename,'w'); $size=count($data); if($line_no==-1) $skip=$size-1; else $skip=$line_no-1; for($line=0;$line<$size;$line++) if($line!=$skip) fputs($pipe,$data[$line]); else $strip_return=TRUE; return $strip_return; } It is possible to refactor this function to not blow up with the 256MB PHP Memory? Give me some clues. Best Regards,

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  • Pass Extra Parameters to JavaScript Callback Function

    - by BRADINO
    Here is a simple example of a function that takes a callback function as a parameter. query.send(handleQueryResponse); function handleQueryResponse(response){      alert('Processing...'); } If you wanted to pass extra variables to the callback function, you can do it like this. var param1 = 'something'; var param2 ='something else'; query.send(function(response) { handleQueryResponse(response, param1, param2) }); function handleQueryResponse(response,param1,param2){      alert('Processing...');      alert(param1);      alert(param2); }

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  • Extreme Optimization – Curves (Function Mapping) Part 1

    - by JoshReuben
    Overview ·        a curve is a functional map relationship between two factors (i.e. a function - However, the word function is a reserved word). ·        You can use the EO API to create common types of functions, find zeroes and calculate derivatives - currently supports constants, lines, quadratic curves, polynomials and Chebyshev approximations. ·        A function basis is a set of functions that can be combined to form a particular class of functions.   The Curve class ·        the abstract base class from which all other curve classes are derived – it provides the following methods: ·        ValueAt(Double) - evaluates the curve at a specific point. ·        SlopeAt(Double) - evaluates the derivative ·        Integral(Double, Double) - evaluates the definite integral over a specified interval. ·        TangentAt(Double) - returns a Line curve that is the tangent to the curve at a specific point. ·        FindRoots() - attempts to find all the roots or zeroes of the curve. ·        A particular type of curve is defined by a Parameters property, of type ParameterCollection   The GeneralCurve class ·        defines a curve whose value and, optionally, derivative and integrals, are calculated using arbitrary methods. A general curve has no parameters. ·        Constructor params:  RealFunction delegates – 1 for the function, and optionally another 2 for the derivative and integral ·        If no derivative  or integral function is supplied, they are calculated via the NumericalDifferentiation  and AdaptiveIntegrator classes in the Extreme.Mathematics.Calculus namespace. // the function is 1/(1+x^2) private double f(double x) {     return 1 / (1 + x*x); }   // Its derivative is -2x/(1+x^2)^2 private double df(double x) {     double y = 1 + x*x;     return -2*x* / (y*y); }   // The integral of f is Arctan(x), which is available from the Math class. var c1 = new GeneralCurve (new RealFunction(f), new RealFunction(df), new RealFunction(System.Math.Atan)); // Find the tangent to this curve at x=1 (the Line class is derived from Curve) Line l1 = c1.TangentAt(1);

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  • Powershell: Install-dotNET4 function

    - by marc dekeyser
    This function will download and install ,NET 4.0. It uses the Get-Framework-Versions function to determine if the installation is necessary or not. Internet Connectivity will be required as the script auto downloads the setup file (and sleeps for 360 seconds... I had a function in there to monitor for install completion at first, turns out the setup file spawns so many childprocesses the function just got confused and locked up -_-)Alternatively you could drop the installation file in the folder specified on the $folderPath variable too. That will skip the download and use the file. This function easily adapts in to other versions f.e. I use it for Powershell 3 installs as well!Function install-dotNet4 () {    if(($InstalledDotNET -eq "4.0") -or ($InstalledDotNET -eq "4.0c")){        write-host ".NET 4.0 Framework is already installed" -foregroundcolor Green    } else{            #set a var for the folder you are looking for        $folderPath = 'C:\Temp'        #Check if folder exists, if not, create it        if (Test-Path $folderpath){            Write-Host "The folder $folderPath exists." -ForeGroundColor Green        } else{            Write-Host "The folder $folderPath does not exist, creating..." -NoNewline -ForegroundColor Red            New-Item $folderpath -type directory | Out-Null            Write-Host " - done!" -ForegroundColor Green        }        # Check if file exists, if not, download it        $file = $folderPath+"\dotNetFx40_Full_x86_x64.exe"        if (Test-Path $file){            write-host "The file $file exists." -ForeGroundColor Green        } else {            #Download Microsoft .Net 4.0 Framework            Write-Host "Downloading Microsoft .Net 4.0 Framework..." -nonewline -ForeGroundColor DarkYellow            $clnt = New-Object System.Net.WebClient            $url = "http://download.microsoft.com/download/9/5/A/95A9616B-7A37-4AF6-BC36-D6EA96C8DAAE/dotNetFx40_Full_x86_x64.exe"            $clnt.DownloadFile($url,$file)            Write-Host " - done!" -ForegroundColor Green        }        #Install Microsoft .Net Framework        Write-Host "Installing Microsoft .Net Framework..." -nonewline -ForegroundColor DarkYellow        $dotNET4 = $folderPath+"\dotNetFx40_Full_x86_x64.exe /quiet /norestart"        Invoke-Expression $dotNET4        write-host " - done!" -ForegroundColor Green        start-sleep -seconds 360    }}

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  • Should you always pass the bare minimum data needed into a function

    - by Anders Holmström
    Let's say I have a function IsAdmin that checks whether a user is an admin. Let's also say that the admin checking is done by matching user id, name and password against some sort of rule (not important). In my head there are then two possible function signatures for this: public bool IsAdmin(User user); public bool IsAdmin(int id, string name, string password); I most often go for the second type of signature, thinking that: The function signature gives the reader a lot more info The logic contained inside the function doesn't have to know about the User class It usually results in slightly less code inside the function However I sometimes question this approach, and also realize that at some point it would become unwieldy. If for example a function would map between ten different object fields into a resulting bool I would obviously send in the entire object. But apart from a stark example like that I can't see a reason to pass in the actual object. I would appreciate any arguments for either style, as well as any general observations you might offer. I program in both object oriented and functional styles, so the question should be seen as regarding any and all idioms.

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  • Naming the implementation version of an interface function

    - by bolov
    When I need to write an implementation version of an interface function, I put the implementation function within a impl namespace, but with the same name as the interface function. Is this a bad practice? (the same name part, the namespace part I am confident it’s more than OK). For me, who I write the code, there is no confusion between the two, but I want to make sure this isn’t confusing for someone else. One other option would be to append impl suffix to the function name, but since it is already in a separate namespace named impl it seems redundant. Is there an idiomatic way to do this? E.g.: namespace n { namespace impl { // implementation function (hidden from users) // same name, is it ok? void foo() { // ... //sometimes it needs to call recursively or to call overloads of the interface version: foo(); // calls the implementation version. Is this confusing? n::foo(); // calls the interface version. Is this confusing? // ... } // namespace impl // interface function (exposed to users) void foo() { impl::foo(); } } // namespace n

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  • Boost.MultiIndex: Are there way to share object between two processes?

    - by Arman
    Hello, I have a Boost.MultiIndex big array about 10Gb. In order to reduce the reading I thought there should be a way to keep the data in the memory and another client programs will be able to read and analyse it. What is the proper way to organize it? The array looks like: struct particleID { int ID;// real ID for particle from Gadget2 file "ID" block unsigned int IDf;// postition in the file particleID(int id,const unsigned int idf):ID(id),IDf(idf){} bool operator<(const particleID& p)const { return ID<p.ID;} unsigned int getByGID()const {return (ID&0x0FFF);}; }; struct ID{}; struct IDf{}; struct IDg{}; typedef multi_index_container< particleID, indexed_by< ordered_unique< tag<IDf>, BOOST_MULTI_INDEX_MEMBER(particleID,unsigned int,IDf)>, ordered_non_unique< tag<ID>,BOOST_MULTI_INDEX_MEMBER(particleID,int,ID)>, ordered_non_unique< tag<IDg>,BOOST_MULTI_INDEX_CONST_MEM_FUN(particleID,unsigned int,getByGID)> > > particlesID_set; Any ideas are welcome. kind regards Arman.

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  • Which is faster for large "for" loop: function call or inline coding?

    - by zaplec
    Hi, I have programmed an embedded software (using C of course) and now I'm considering ways to improve the running time of the system. The most important single module in my system is one very large nested for loop module. That module consists of two nested for loops that loops max 122500 times. That's not very much yet, but the problem is that inside that nested for loop I have a function call to a function that is in another source file. That specific function consists mostly of two another nested for loops which loops always 22500 times. So now I have to make a function call 122500 times. I have made that function that is to be called a lot lighter and shorter (yet still works as it should) and now I started to think that would it be faster to rip off that function call and write that process directly inside those first two for loops? The processor in that system is ARM7TDMI and its frequency is 55MHz. The system itself isn't very time critical so it doesn't have to be real time capable. However the faster it can process its duties the better. Also would it be also faster to use while loops instead of fors? And any piece of advice about how to improve the running time is appreciated. -zaplec

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  • Why there is no scoped locks for multiple mutexes in C++0x or Boost.Thread?

    - by Vicente Botet Escriba
    C++0x thread library or Boost.thread define non-member variadic template function that lock all lock avoiding dead lock. template <class L1, class L2, class... L3> void lock(L1&, L2&, L3&...); While this function avoid help to deadlock, the standard do not includes the associated scoped lock to write exception safe code. { std::lock(l1,l2); // do some thing // unlock li l2 exception safe } That means that we need to use other mechanism as try-catch block to make exception safe code or define our own scoped lock on multiple mutexes ourselves or even do that { std::lock(l1,l2); std::unique_lock lk1(l1, std::adopted); std::unique_lock lk2(l2, std::adopted); // do some thing // unlock li l2 on destruction of lk1 lk2 } Why the standard doesn't includes a scoped lock on multiple mutexes of the same type, as for example { std::array_unique_lock<std::mutex> lk(l1,l2); // do some thing // unlock l1 l2 on destruction of lk } or tuples of mutexes { std::tuple_unique_lock<std::mutex, std::recursive_mutex> lk(l1,l2); // do some thing // unlock l1 l2 on destruction of lk } Is there something wrong on the design?

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  • Setting up separate ctags db's for C/C++ standard libs, boost, and third party libs

    - by Robert S. Barnes
    I want to set up separate ctags databases for various libraries in /usr/include/ for use with OmniCppComplete. The idea is to be able to pull in only the libraries needed for a particular project in the target language - C or C++. For example, I'd like to have one database for the standard C libraries, one for system libraries that might be used by either C or C++ programs ( sockets / networking comes to mind ) one for the standard C++ libs / STL / Boost, and then other databases for various third party libraries such as QT or glib. Then I could pull something in simply by typing set tags+= ~/.vim/somelib.tags in vim. I assume that everything related to the C++ stdlib and STL are in the /usr/include/c++ and that Boost is all in /usr/include/boost. Unfortunately it seems that the standard C libs and system libs are just kind of dumped directly into /usr/include/ with a variety of other stuff. How can I get a list of which files and directories belong to which libs? I'm on Ubuntu 8.04.

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  • JavaScript: Can I declare a variable by querying which function is called? (Newbie)

    - by belle3WA
    I'm working with an existing JavaScript-powered cart module that I am trying to modify. I do not know JS and for various reasons need to work with what is already in place. The text that appears for my quantity box is defined within an existing function: function writeitems() { var i; for (i=0; i<items.length; i++) { var item=items[i]; var placeholder=document.getElementById("itembuttons" + i); var s="<p>"; // options, if any if (item.options) { s=s+"<select id='options"+i+"'>"; var j; for (j=0; j<item.options.length; j++) { s=s+"<option value='"+item.options[j].name+"'>"+item.options[j].name+"</option>"; } s=s+"</select>&nbsp;&nbsp;&nbsp;"; } // add to cart s=s+method+"Quantity: <input id='quantity"+i+"' value='1' size='3'/> "; s=s+"<input type='submit' value='Add to Cart' onclick='addtocart("+i+"); return false;'/></p>"; } placeholder.innerHTML=s; } refreshcart(false); } I have two different types of quantity input boxes; one (donations) needs to be prefaced with a dollar sign, and one (items) should be blank. I've taken the existing additem function, copied it, and renamed it so that there are two identical functions, one for items and one for donations. The additem function is below: function additem(name,cost,quantityincrement) { if (!quantityincrement) quantityincrement=1; var index=items.length; items[index]=new Object; items[index].name=name; items[index].cost=cost; items[index].quantityincrement=quantityincrement; document.write("<span id='itembuttons" + index + "'></span>"); return index; } Is there a way to declare a global variable based on which function (additem or adddonation) is called so that I can add that into the writeitems function so display or hide the dollar sign as needed? Or is there a better solution? I can't use HTML in the body of the cart page because of the way it is currently coded, so I'm depending on the JS to take care of it. Any help for a newbie is welcome. Thanks!

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  • Function like C# properties?

    - by alan2here
    I was directed here from SO as a better stack exchange site for this question. I've been thinking about the neatness and expression of C# properties over functions, although they only currently work where no parameters are used, and wondered. Is is possible, and if so why not, to have a stand alone function like C# property. For example: public class test { private byte n = 4; public test() { func = 2; byte n2 = func; func; } private byte func { get { return n; } set { n = value; } func { n++; } } } edit: Sorry for the vagueness first time round. I'm going to add some info and motivation. The 'n++' here is just a simple example, a placeholder, it's not intended to be representative of the actual code that would be used. I'm also looking at this from the point of view of looking at the property command as is, not in the context of using it for 'get_xyz' and 'set_xyz' member functions, which is certainly useful, but of instead comparing it more abstractly to functions and other programic elements. A 'get' property can be used instead of a function that takes no parameters, and syntactically they are perhaps only aesthetically, but as I see it noticeably nicer. However, properties also add the potential for an extra layer of polymorphism, one that relates to the 'func = 4;' getting, 'int n = func;' setting or 'func;' function like context in which they are used as well as the more common parameter based polymorphism. Potentially allowing for a lot of expression and contextual information reguarding how other would use your functions. As in many places uses and definitions would remain the same, it shouldn't break existing code. private byte func { get { } get bool { } set { } func { } func(bool) { } func(byte, myType) { } // etc... } So a read only function would look like this: private byte func { get { } } A normal function like this: private void func { func { } } A function with parameter polymorphism like this: private byte func { func(bool) { } func(byte, myType) { } } And a function that could return a value, or just compute, depending on the context it is used, that also has more conventional parameter polymorphism as well, like so: private byte func { get { } func(bool) { } func(byte, myType) { } }

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  • Why can't I extract a C++ type from a Python type using boost::python::extractor?

    - by Robin
    I've wrapped a C++ class using Py++ and everything is working great in Python. I can instantiate the c++ class, call methods, etc. I'm now trying to embed some Python into a C++ application. This is also working fine for the most-part. I can call functions on a Python module, get return values, etc. The python code I'm calling returns one of the classes that I wrapped: import _myextension as myext def run_script(arg): my_cpp_class = myext.MyClass() return my_cpp_class I'm calling this function from C++ like this: // ... excluding error checking, ref counting, etc. for brevity ... PyObject *pModule, *pFunc, *pArgs, *pReturnValue; Py_Initialize(); pModule = PyImport_Import(PyString_FromString("cpp_interface")); pFunc = PyObject_GetAttrString(pModule, "run_script"); pArgs = PyTuple_New(1); PyTuple_SetItem(pArgs, 0, PyString_FromString("an arg")); pReturnValue = PyObject_CallObject(pFunc, pArgs); bp::extract< MyClass& > extractor(pReturnValue); // PROBLEM IS HERE if (extractor.check()) { // This check is always false MyClass& cls = extractor(); } The problem is the extractor never actually extracts/converts the PyObject* to MyClass (i.e. extractor.check() is always false). According to the docs this is the correct way to extract a wrapped C++ class. I've tried returning basic data types (ints/floats/dicts) from the Python function and all of them are extracted properly. Is there something I'm missing? Is there another way to get the data and cast to MyClass?

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  • Why does Visual Studio 2010 throw this error with Boost 1.42.0?

    - by ra170
    I'm trying to recompile application, that compiles fine with warning level 4 in visual studio 2005 and visual studio 2008. Since the errors (look below) are coming from std:tr1, I'm thinking there's some conflict, but not sure how to fix. My first thought was to remove all references to boost, such as but then I get an error that it can't find format method. So here's one of the errors: (not sure what it means) Any ideas, suggestions, solutions? Thanks! > c:\program files (x86)\microsoft > visual studio > 10.0\vc\include\type_traits(197): error C2752: > 'std::tr1::_Remove_reference<_Ty>' : > more than one partial specialization > matches the template argument list 1> > with 1> [ 1> > _Ty=bool (__cdecl &)(const BlahBlah &) 1> ] 1> c:\program > files (x86)\microsoft visual studio > 10.0\vc\include\xtr1common(356): could be > 'std::tr1::_Remove_reference<_Ty&&>' > 1> c:\program files > (x86)\microsoft visual studio > 10.0\vc\include\xtr1common(350): or 'std::tr1::_Remove_reference<_Ty&>' 1> > c:\program files (x86)\microsoft > visual studio > 10.0\vc\include\type_traits(962) : see reference to class template > instantiation > 'std::tr1::remove_reference<_Ty>' > being compiled 1> with

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  • How to boost system sound output?

    - by infant programmer
    When I use Earphones, I feel that my system output is very low, I have set all the volume output to maximum in "control panel\Sounds and Audio devices", but still not satisfactory. May be my earphones output proportionality is lower. No problem with sub-woofer, I think its because of the amplifier. Is there any software to boost up system volume output to compensate ?

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  • Rewrite rules for Drupal Boost with Lighttpd

    - by bsdjunkie
    I have been given the super task of preparing a web site to get hammered.... Or site is drupal based, I have found what could be my answer in the form of Boost. But I can't for the life of me find any information on the Lighttpd rewrite rules to make it function. All suggestion welcome! Thanks

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  • EXCEL function working like SQL group by + count(distinct *)?

    - by Solo
    Suppose I have an EXCEL sheet with below data CODE (COL A) | VALUE (COL B) ============================== A01 | 10 A01 | 20 A01 | 30 A01 | 10 B01 | 30 B01 | 30 Is there an EXCEL function working like .. SELECT CODE, count (Distinct *) FROM TABLE GROUP BY CODE CODE | Distinct Count of Value =================================== A01 | 3 B01 | 1 or, better yet, Can we have an excel formula pasted in Column C to get something like this: CODE (COL A) | VALUE (COL B) | DISTINCT VALUE COUNT WITH MATCHING CODE (COL C) =============================================================================== A01 | 10 | 3 A01 | 20 | 3 A01 | 30 | 3 A01 | 10 | 3 B01 | 30 | 1 B01 | 30 | 1 I know I can use pivot table to get this result easily. However due to reporting requirements I have to append the "distinct count" column to the excel sheet, hence pivot table is not an option. My last resort is to use Excel Macro (Which is fine), but before that I would like to learn whether excel functions can accomplish this kind of task. Many thanks!

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  • What function should I use in Excel for searching a (multiple) text string?

    - by Alenanno
    The title is a bit unclear, but I'll be explaining it now for better clarity. I have this: When I type in the Input field, I'd like Excel to show me the result in the Output field. For example, if I write Four, I'd like it to output 20, or if I write one of the other three words, then 12. The problem is that... I can't make it to work. The formula I tried is "=CERCA(C2;G:G;H:H)" (cerca means search), so I'm saying "Take what I write in the cell C2, search through the column G and give me what you find from the column H", but the result is always N.D. (Not available). I've tried other combinations and: Text strings, does not work; Single numbers, works (if I search 1, it says 2, which is what I expect); multiple numbers, does not work (if I search 4, nothing happens). What function should I use?

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  • Unable to create unmanaged object using new keyword in managed C++

    - by chair79
    Hi all, I've created a class with a boost::unordered_map as a member, Linkage.h #ifndef LINKAGE_H #define LINKAGE_H #include <boost/unordered_map.hpp> class Linkage { private: boost::unordered_map<int, int> m_IOMap; public: .... }; Linkage.cpp #include "stdafx.h" ... // methods and in the managed side of C++, I try to create the pointer of the obj: private: System::Void Form1_Load(System::Object^ sender, System::EventArgs^ e) { Linkage* m_pLink = new Linkage(); ..... } However this produces errors: Error 4 error LNK2005: "private: static unsigned int const boost::detail::type_with_alignment_imp<4>::found" (?found@?$type_with_alignment_imp@$03@detail@boost@@$$Q0IB) already defined in Proj_Test.obj Linkage.obj ..... Error 7 fatal error LNK1169: one or more multiply defined symbols found Could anyone explain to me pls? Thanks.

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  • getting names subgroups

    - by Abruzzo Forte e Gentile
    Hi All I am working with the new version of boost 1.42 and I want to use regex with named sub groups. Below an example. std::string line("match this here FIELD=VALUE in the middle"); boost::regex rgx("FIELD=(?\\w+)", boost::regex::perl ); boost::smatch thisMatch; boost::regex_searh( line, thisMatch, rgx ); Do you know how to get the content of the match ? The traditional way is std::string result( mtch["VAL"].first, mtch["VAL"].second ); but i don't want to use this way. I want to use the name of the subgroups as usual in Perl and in regex in general. I tried this, but it didn't work. std::string result( mtch["VAL"].first, mtch["VAL"].second ); Do you know how to get the value using the name of the subgroup? Thanks AFG

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  • typedef declaration syntax

    - by mt_serg
    Some days ago I looked at boost sources and found interesting typedef. There is a code from "boost\detail\none_t.hpp": namespace boost { namespace detail { struct none_helper{}; typedef int none_helper::*none_t ; } // namespace detail } // namespace boost I didn't see syntax like that earlier and can't explain the sense of that. This typedef introduces name "none_t" as pointer to int in boost::detail namespace. What the syntax is? And what difference between "typedef int none_helper::*none_t" and for example "typedef int *none_t" ?

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  • File Segmentation when trying to write in a file

    - by user1286390
    I am trying in C language to use the method of bisection to find the roots of some equation, however when I try to write every step of this process in a file I get the problem "Segmentation fault". This might be an idiot fault that I did, however I have been trying to solve this for a long time. I am compiling using gcc and that is the code: #include <stdio.h> #include <stdlib.h> #include <math.h> #define R 1.0 #define h 1.0 double function(double a); void attractor(double *a1, double *a2, double *epsilon); void attractor(double *a1, double *a2, double *epsilon) { FILE* bisection; double a2_copia, a3, fa1, fa2; bisection = fopen("bisection-part1.txt", "w"); fa1 = function(*a1); fa2 = function(*a2); if(function(*a1) - function(*a2) > 0.0) *epsilon = function(*a1) - function(*a2); else *epsilon = function(*a2) - function(*a1); fprintf(bisection, "a1 a2 fa1 fa2 epsilon\n"); a2_copia = 0.0; if(function(*a1) * function(*a2) < 0.0 && *epsilon >= 0.00001) { a3 = *a2 - (*a2 - *a1); a2_copia = *a2; *a2 = a3; if(function(*a1) - function(*a2) > 0.0) *epsilon = function(*a1) - function(*a2); else *epsilon = function(*a2) - function(*a1); if(function(*a1) * function(*a2) < 0.0 && *epsilon >= 0.00001) { fprintf(bisection, "%.4f %.4f %.4f %.4f %.4f\n", *a1, *a2, function(*a1), function(*a1), *epsilon); attractor(a1, a2, epsilon); } else { *a2 = a2_copia; *a1 = a3; if(function(*a1) - function(*a2) > 0) *epsilon = function(*a1) - function(*a2); else *epsilon = function(*a2) - function(*a1); if(function(*a1) * function(*a2) < 0.0 && *epsilon >= 0.00001) { fprintf(bisection, "%.4f %.4f %.4f %.4f %.4f\n", *a1, *a2, function(*a1), function(*a1), *epsilon); attractor(a1, a2, epsilon); } } } fa1 = function(*a1); fa2 = function(*a2); if(function(*a1) - function(*a2) > 0.0) *epsilon = function(*a1) - function(*a2); else *epsilon = function(*a2) - function(*a1); fprintf(bisection, "%.4f %.4f %.4f %.4f %.4f\n", a1, a2, fa1, fa2, epsilon); } double function(double a) { double fa; fa = (a * cosh(h / (2 * a))) - R; return fa; } int main() { double a1, a2, fa1, fa2, epsilon; a1 = 0.1; a2 = 0.5; fa1 = function(a1); fa2 = function(a2); if(fa1 - fa2 > 0.0) epsilon = fa1 - fa2; else epsilon = fa2 - fa1; if(epsilon >= 0.00001) { fa1 = function(a1); fa2 = function(a2); attractor(&a1, &a2, &epsilon); fa1 = function(a1); fa2 = function(a2); if(fa1 - fa2 > 0.0) epsilon = fa1 - fa2; else epsilon = fa2 - fa1; } if(epsilon < 0.0001) printf("Vanish at %f", a2); else printf("ERROR"); return 0; } Thanks anyway and sorry if this question is not suitable.

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  • Line by Line explanation of "Javascript: Good Parts" example?

    - by Matrym
    I'm reading "Javascript: The Good Parts" and am totally baffled by what's really going on here. A more detailed and/or simplified explanation would be greatly appreciated. // BAD EXAMPLE // Make a function that assigns event handler functions to an array of nodes the wrong way. // When you click on a node, an alert box is supposed to display the ordinal of the node. // But it always displays the number of nodes instead. var add_the_handlers = function (nodes) { var i; for (i = 0; i < nodes.length; i += 1) { nodes[i].onclick = function (e) { alert(i); } } }; // END BAD EXAMPLE The add_the_handlers function was intended to give each handler a unique number (i). It fails because the handler functions are bound to the variable i, not the value of the variable i at the time the function was made: // BETTER EXAMPLE // Make a function that assigns event handler functions to an array of nodes the right way. // When you click on a node, an alert box will display the ordinal of the node. var add_the_handlers = function (nodes) { var i; for (i = 0; i < nodes.length; i += 1) { nodes[i].onclick = function (i) { return function (e) { alert(i); }; }(i); } }; Now, instead of assigning a function to onclick, we define a function and immediately invoke it, passing in i. That function will return an event handler function that is bound to the value of i that was passed in, not to the i defined in add_the_handlers. That returned function is assigned to onclick.

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  • SQL SERVER – Puzzle to Win Print Book – Explain Value of PERCENTILE_CONT() Using Simple Example

    - by pinaldave
    From last several days I am working on various Denali Analytical functions and it is indeed really fun to refresh the concept which I studied in the school. Earlier I wrote article where I explained how we can use PERCENTILE_CONT() to find median over here SQL SERVER – Introduction to PERCENTILE_CONT() – Analytic Functions Introduced in SQL Server 2012. Today I am going to ask question based on the same blog post. Again just like last time the intention of this puzzle is as following: Learn new concept of SQL Server 2012 Learn new concept of SQL Server 2012 even if you are on earlier version of SQL Server. On another note, SQL Server 2012 RC0 has been announced and available to download SQL SERVER – 2012 RC0 Various Resources and Downloads. Now let’s have fun following query: USE AdventureWorks GO SELECT SalesOrderID, OrderQty, ProductID, PERCENTILE_CONT(0.5) WITHIN GROUP (ORDER BY ProductID) OVER (PARTITION BY SalesOrderID) AS MedianCont FROM Sales.SalesOrderDetail WHERE SalesOrderID IN (43670, 43669, 43667, 43663) ORDER BY SalesOrderID DESC GO The above query will give us the following result: The reason we get median is because we are passing value .05 to PERCENTILE_COUNT() function. Now run read the puzzle. Puzzle: Run following T-SQL code: USE AdventureWorks GO SELECT SalesOrderID, OrderQty, ProductID, PERCENTILE_CONT(0.9) WITHIN GROUP (ORDER BY ProductID) OVER (PARTITION BY SalesOrderID) AS MedianCont FROM Sales.SalesOrderDetail WHERE SalesOrderID IN (43670, 43669, 43667, 43663) ORDER BY SalesOrderID DESC GO Observe the result and you will notice that MidianCont has different value than before, the reason is PERCENTILE_CONT function has 0.9 value passed. For first four value the value is 775.1. Now run following T-SQL code: USE AdventureWorks GO SELECT SalesOrderID, OrderQty, ProductID, PERCENTILE_CONT(0.1) WITHIN GROUP (ORDER BY ProductID) OVER (PARTITION BY SalesOrderID) AS MedianCont FROM Sales.SalesOrderDetail WHERE SalesOrderID IN (43670, 43669, 43667, 43663) ORDER BY SalesOrderID DESC GO Observe the result and you will notice that MidianCont has different value than before, the reason is PERCENTILE_CONT function has 0.1 value passed. For first four value the value is 709.3. Now in my example I have explained how the median is found using this function. You have to explain using mathematics and explain (in easy words) why the value in last columns are 709.3 and 775.1 Hint: SQL SERVER – Introduction to PERCENTILE_CONT() – Analytic Functions Introduced in SQL Server 2012 Rules Leave a comment with your detailed answer by Nov 25's blog post. Open world-wide (where Amazon ships books) If you blog about puzzle’s solution and if you win, you win additional surprise gift as well. Prizes Print copy of my new book SQL Server Interview Questions Amazon|Flipkart If you already have this book, you can opt for any of my other books SQL Wait Stats [Amazon|Flipkart|Kindle] and SQL Programming [Amazon|Flipkart|Kindle]. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL Function, SQL Puzzle, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, T SQL, Technology

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