Search Results

Search found 38961 results on 1559 pages for 'boost function'.

Page 46/1559 | < Previous Page | 42 43 44 45 46 47 48 49 50 51 52 53  | Next Page >

  • Boost Mersenne Twister: how to seed with more than one value?

    - by Eamon Nerbonne
    I'm using the boost mt19937 implementation for a simulation. The simulation needs to be reproducible, and that means storing and potentially reusing the RNG seeds later. I'm using the windows crypto api to generate the seed values because I need an external source for the seeds and not because of any particular guarantees of randomness. The output of any simulation run will have a note including the RNG seed - so the seed needs to be reasonably short. On the other hand, as part of the analysis of the simulation, I'll be comparing several runs - but to be sure that these runs are actually different, I'll need to use different seeds - so the seed needs to be long enough to avoid accidental collisions. I've determined that 64-bits of seeding should suffice; the chance of a collision will reach 50% after about 2^32 runs - that probability is low enough that the average error caused by it is negligible to me. Using just 32-bits of seed is tricky; the chance of a collision reaches 50% already after 2^16 runs; and that's a little too likely for my tastes. Unfortunately, the boost implementation either seeds with a full state vector - which is far, far too long - or a single 32-bit unsigned long - which isn't ideal. How can I seed the generator with more than 32-bits but less than a full state vector? I tried just padding the vector or repeating the seeds to fill the state vector, but even a cursory glance at the results shows that that generates poor results.

    Read the article

  • Is there a Boost (or other common lib) type for matrices with string keys?

    - by mohawkjohn
    I have a dense matrix where the indices correspond to genes. While gene identifiers are often integers, they are not contiguous integers. They could be strings instead, too. I suppose I could use a boost sparse matrix of some sort with integer keys, and it wouldn't matter if they're contiguous. Or would this still occupy a great deal of space, particularly if some genes have identifiers that are nine digits? Further, I am concerned that sparse storage is not appropriate, since this is an all-by-all matrix (there will be a distance in each and every cell, provided the gene exists). I'm unlikely to need to perform any matrix operations (e.g., matrix multiplication). I will need to pull vectors out of the matrix (slices). It seems like the best type of matrix would be keyed by a Boost unordered_map (a hash map), or perhaps even simply an STL map. Am I looking at this the wrong way? Do I really need to roll my own? I thought I saw such a class somewhere before. Thanks!

    Read the article

  • Compiling my Boost/NTL program with c++ on Linux.

    - by Martin Lauridsen
    Hi SO, I wrote a client program and a server program, that uses the NTL library and Boost::Asio, to do client/server communication for an integer factorization application, in C++. Both sides consist of several headers and cpp files. Both project compile fine individually on Windows in Visual Studio. All I did, was add the include path of NTL and Boost to both projects: Additional include paths: "D:\Downloads\WinNTL-5_5_2\include";D:\boost_1_42_0 Furthermore, for both projects, I added the two library paths to both projects in VS: Additional library directories: D:\boost_1_42_0\stage\lib;"D:\Documents\Visual Studio 2008\Projects\ntl\Debug" And added under Additional dependencies: ntl.lib As said, it compiles fine on Windows. But when I put the code on a Linux machine provided by university, I try to compile with the following statement c++ -I/appl/htopopt/Linux_x86_64/NTL-5.4.2/include -I/appl/htopopt/Linux_x86_64/boost_1_43_0/include client_protocol.cpp mpqs_client.cpp mpqs_sieve.cpp mpqs_helper.cpp -o mpqs_helper -L/appl/htopopt/Linux_x86_64/NTL-5.4.2/lib -lntl -L/appl/htopopt/Linux_x86_64/gmp-4.2.1/lib -lgmp -lm -L/appl/htopopt/Linux_x86_64/boost_1_43_0/lib -lboost_system -static Upon doing this, I get a huuuge error, which I posted here. Any idea how to fix this, please??

    Read the article

  • (How) Can I approximate a "dynamic" index (key extractor) for Boost MultiIndex?

    - by Sarah
    I have a MultiIndex container of boost::shared_ptrs to members of class Host. These members contain private arrays bool infections[NUM_SEROTYPES] revealing Hosts' infection statuses with respect to each of 1,...,NUM_SEROTYPES serotypes. I want to be able to determine at any time in the simulation the number of people infected with a given serotype, but I'm not sure how: Ideally, Boost MultiIndex would allow me to sort, for example, by Host::isInfected( int s ), where s is the serotype of interest. From what I understand, MultiIndex key extractors aren't allowed to take arguments. An alternative would be to define an index for each serotype, but I don't see how to write the MultiIndex container typedef ... in such an extensible way. I will be changing the number of serotypes between simulations. (Do experienced programmers think this should be possible? I'll attempt it if so.) There are 2^(NUM_SEROTYPES) possible infection statuses. For small numbers of serotypes, I could use a single index based on this number (or a binary string) and come up with some mapping from this key to actual infection status. Counting is still darn slow. I could maintain a separate structure counting the total numbers of infecteds with each serotype. The synchrony is a bit of a pain, but the memory is fine. I would prefer a slicker option, since I would like to do further sorts on other host attributes (e.g., after counting the number infected with serotype s, count the number of those infected who are also in a particular household and have a particular age). Thanks in advance.

    Read the article

  • How to get SQL Function run a different query and return value from either query?

    - by RoguePlanetoid
    I need a function, but cannot seem to get it quite right, I have looked at examples here and elsewhere and cannot seem to get this just right, I need an optional item to be included in my query, I have this query (which works): SELECT TOP 100 PERCENT SKU, Description, LEN(CONVERT(VARCHAR (1000),Description)) AS LenDesc FROM tblItem WHERE Title = @Title AND Manufacturer = @Manufacturer ORDER BY LenDesc DESC This works within a Function, however the Manufacturer is Optional for this search - which is to find the description of a similar item, if none is present, the other query is: SELECT TOP 100 PERCENT SKU, Description, LEN(CONVERT(VARCHAR (1000),Description)) AS LenDesc FROM tblItem WHERE Title = @Title ORDER BY LenDesc DESC Which is missing the Manufacturer, how to I get my function to use either query based on the Manufacturer Value being present or not. The reason is I will have a function which first checks an SKU for a Description, if it is not present - it uses this method to get a Description from a Similar Product, then updates the product being added with the similar product's description. Here is the function so far: ALTER FUNCTION [dbo].[GetDescriptionByTitleManufacturer] ( @Title varchar(400), @Manufacturer varchar(160) ) RETURNS TABLE AS RETURN ( SELECT TOP 100 PERCENT SKU, Description, LEN(CONVERT(VARCHAR (1000),Description)) AS LenDesc FROM tblItem WHERE Title = @Title AND Manufacturer = @Manufacturer ORDER BY LenDesc DESC ) I've tried adding BEGINs and IF...ELSEs but get errors or syntax problems each way I try it, I want to be able to do something like this pseudo-function (which does not work): ALTER FUNCTION [dbo].[GetDescriptionByTitleManufacturer] ( @Title varchar(400), @Manufacturer varchar(160) ) RETURNS TABLE AS BEGIN IF (@Manufacturer = Null) RETURN ( SELECT TOP 100 PERCENT SKU, Description, LEN(CONVERT(VARCHAR (1000),Description)) AS LenDesc FROM tblItem WHERE Title = @Title ORDER BY LenDesc DESC ) ELSE RETURN ( SELECT TOP 100 PERCENT SKU, Description, LEN(CONVERT(VARCHAR (1000),Description)) AS LenDesc FROM tblItem WHERE Title = @Title AND Manufacturer = @Manufacturer ORDER BY LenDesc DESC ) END

    Read the article

  • SQL SERVER – Introduction to PERCENTILE_DISC() – Analytic Functions Introduced in SQL Server 2012

    - by pinaldave
    SQL Server 2012 introduces new analytical function PERCENTILE_DISC(). The book online gives following definition of this function: Computes a specific percentile for sorted values in an entire rowset or within distinct partitions of a rowset in Microsoft SQL Server 2012 Release Candidate 0 (RC 0). For a given percentile value P, PERCENTILE_DISC sorts the values of the expression in the ORDER BY clause and returns the value with the smallest CUME_DIST value (with respect to the same sort specification) that is greater than or equal to P. If you are clear with understanding of the function – no need to read further. If you got lost here is the same in simple words – find value of the column which is equal or more than CUME_DIST. Before you continue reading this blog I strongly suggest you read about CUME_DIST function over here Introduction to CUME_DIST – Analytic Functions Introduced in SQL Server 2012. Now let’s have fun following query: USE AdventureWorks GO SELECT SalesOrderID, OrderQty, ProductID, CUME_DIST() OVER(PARTITION BY SalesOrderID ORDER BY ProductID ) AS CDist, PERCENTILE_DISC(0.5) WITHIN GROUP (ORDER BY ProductID) OVER (PARTITION BY SalesOrderID) AS PercentileDisc FROM Sales.SalesOrderDetail WHERE SalesOrderID IN (43670, 43669, 43667, 43663) ORDER BY SalesOrderID DESC GO The above query will give us the following result: You can see that I have used PERCENTILE_DISC(0.5) in query, which is similar to finding median but not exactly. PERCENTILE_DISC() function takes a percentile as a passing parameters. It returns the value as answer which value is equal or great to the percentile value which is passed into the example. For example in above example we are passing 0.5 into the PERCENTILE_DISC() function. It will go through the resultset and identify which rows has values which are equal to or great than 0.5. In first example it found two rows which are equal to 0.5 and the value of ProductID of that row is the answer of PERCENTILE_DISC(). In some third windowed resultset there is only single row with the CUME_DIST() value as 1 and that is for sure higher than 0.5 making it as a answer. To make sure that we are clear with this example properly. Here is one more example where I am passing 0.6 as a percentile. Now let’s have fun following query: USE AdventureWorks GO SELECT SalesOrderID, OrderQty, ProductID, CUME_DIST() OVER(PARTITION BY SalesOrderID ORDER BY ProductID ) AS CDist, PERCENTILE_DISC(0.6) WITHIN GROUP (ORDER BY ProductID) OVER (PARTITION BY SalesOrderID) AS PercentileDisc 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 result of the PERCENTILE_DISC(0.6) is ProductID of which CUME_DIST() is more than 0.6. This means for SalesOrderID 43670 has row with CUME_DIST() 0.75 is the qualified row, resulting answer 773 for ProductID. I hope this explanation makes it further clear. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL Function, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, T SQL, Technology

    Read the article

  • Error when make "make install" PHP WebDav

    - by kron
    Hi, I'm having issues install PHP WebDAV onto Fedora8 - after downloading and running make install I get the following errors: [root@ip-18-192-114-35 dav]# make install /bin/sh /tmp/dav/libtool --mode=compile gcc -I. -I/tmp/dav -DPHP_ATOM_INC -I/tmp/dav/include -I/tmp/dav/main -I/tmp/dav -I/usr/include/php -I/usr/include/php/main -I/usr/include/php/TSRM -I/usr/include/php/Zend -I/usr/include/php/ext -I/usr/include/php/ext/date/lib -DHAVE_CONFIG_H -g -O2 -c /tmp/dav/dav.c -o dav.lo gcc -I. -I/tmp/dav -DPHP_ATOM_INC -I/tmp/dav/include -I/tmp/dav/main -I/tmp/dav -I/usr/include/php -I/usr/include/php/main -I/usr/include/php/TSRM -I/usr/include/php/Zend -I/usr/include/php/ext -I/usr/include/php/ext/date/lib -DHAVE_CONFIG_H -g -O2 -c /tmp/dav/dav.c -fPIC -DPIC -o .libs/dav.o /tmp/dav/dav.c:21:23: error: ne_socket.h: No such file or directory /tmp/dav/dav.c:22:24: error: ne_session.h: No such file or directory /tmp/dav/dav.c:23:22: error: ne_utils.h: No such file or directory /tmp/dav/dav.c:24:21: error: ne_auth.h: No such file or directory /tmp/dav/dav.c:25:22: error: ne_basic.h: No such file or directory /tmp/dav/dav.c:26:20: error: ne_207.h: No such file or directory /tmp/dav/dav.c:35: error: expected specifier-qualifier-list before 'ne_session' /tmp/dav/dav.c: In function 'dav_destructor_dav_session': /tmp/dav/dav.c:152: error: 'DavSession' has no member named 'sess' /tmp/dav/dav.c:153: error: 'DavSession' has no member named 'sess' /tmp/dav/dav.c:155: error: 'DavSession' has no member named 'base_uri_path' /tmp/dav/dav.c:156: error: 'DavSession' has no member named 'user_name' /tmp/dav/dav.c:157: error: 'DavSession' has no member named 'user_password' /tmp/dav/dav.c:158: error: 'DavSession' has no member named 'sess' /tmp/dav/dav.c: In function 'cb_dav_auth': /tmp/dav/dav.c:194: error: 'DavSession' has no member named 'user_name' /tmp/dav/dav.c:194: error: 'NE_ABUFSIZ' undeclared (first use in this function) /tmp/dav/dav.c:194: error: (Each undeclared identifier is reported only once /tmp/dav/dav.c:194: error: for each function it appears in.) /tmp/dav/dav.c:195: error: 'DavSession' has no member named 'user_password' /tmp/dav/dav.c: In function 'zif_webdav_connect': /tmp/dav/dav.c:212: error: 'ne_session' undeclared (first use in this function) /tmp/dav/dav.c:212: error: 'sess' undeclared (first use in this function) /tmp/dav/dav.c:213: error: 'ne_uri' undeclared (first use in this function) /tmp/dav/dav.c:213: error: expected ';' before 'uri' /tmp/dav/dav.c:215: error: 'uri' undeclared (first use in this function) /tmp/dav/dav.c:259: error: 'DavSession' has no member named 'base_uri_path' /tmp/dav/dav.c:260: error: 'DavSession' has no member named 'base_uri_path_len' /tmp/dav/dav.c:262: error: 'DavSession' has no member named 'user_name' /tmp/dav/dav.c:264: error: 'DavSession' has no member named 'user_name' /tmp/dav/dav.c:267: error: 'DavSession' has no member named 'user_password' /tmp/dav/dav.c:269: error: 'DavSession' has no member named 'user_password' /tmp/dav/dav.c:271: error: 'DavSession' has no member named 'sess' /tmp/dav/dav.c: In function 'get_full_uri': /tmp/dav/dav.c:304: error: 'DavSession' has no member named 'base_uri_path_len' /tmp/dav/dav.c:307: error: 'DavSession' has no member named 'base_uri_path_len' /tmp/dav/dav.c:313: error: 'DavSession' has no member named 'base_uri_path' /tmp/dav/dav.c:313: error: 'DavSession' has no member named 'base_uri_path_len' /tmp/dav/dav.c:314: error: 'DavSession' has no member named 'base_uri_path_len' /tmp/dav/dav.c: In function 'zif_webdav_get': /tmp/dav/dav.c:329: error: 'ne_session' undeclared (first use in this function) /tmp/dav/dav.c:329: error: 'sess' undeclared (first use in this function) /tmp/dav/dav.c:330: error: 'ne_request' undeclared (first use in this function) /tmp/dav/dav.c:330: error: 'req' undeclared (first use in this function) /tmp/dav/dav.c:348: error: 'DavSession' has no member named 'sess' /tmp/dav/dav.c:354: error: 'ne_accept_2xx' undeclared (first use in this function) /tmp/dav/dav.c:359: error: 'NE_OK' undeclared (first use in this function) /tmp/dav/dav.c:359: error: invalid type argument of '->' /tmp/dav/dav.c: In function 'zif_webdav_put': /tmp/dav/dav.c:377: error: 'ne_session' undeclared (first use in this function) /tmp/dav/dav.c:377: error: 'sess' undeclared (first use in this function) /tmp/dav/dav.c:378: error: 'ne_request' undeclared (first use in this function) /tmp/dav/dav.c:378: error: 'req' undeclared (first use in this function) /tmp/dav/dav.c:396: error: 'DavSession' has no member named 'sess' /tmp/dav/dav.c:405: error: 'NE_OK' undeclared (first use in this function) /tmp/dav/dav.c:405: error: invalid type argument of '->' /tmp/dav/dav.c: In function 'zif_webdav_delete': /tmp/dav/dav.c:422: error: 'ne_session' undeclared (first use in this function) /tmp/dav/dav.c:422: error: 'sess' undeclared (first use in this function) /tmp/dav/dav.c:423: error: 'ne_request' undeclared (first use in this function) /tmp/dav/dav.c:423: error: 'req' undeclared (first use in this function) /tmp/dav/dav.c:441: error: 'DavSession' has no member named 'sess' /tmp/dav/dav.c:448: error: 'NE_OK' undeclared (first use in this function) /tmp/dav/dav.c:448: error: invalid type argument of '->' /tmp/dav/dav.c: In function 'zif_webdav_mkcol': /tmp/dav/dav.c:465: error: 'ne_session' undeclared (first use in this function) /tmp/dav/dav.c:465: error: 'sess' undeclared (first use in this function) /tmp/dav/dav.c:466: error: 'ne_request' undeclared (first use in this function) /tmp/dav/dav.c:466: error: 'req' undeclared (first use in this function) /tmp/dav/dav.c:484: error: 'DavSession' has no member named 'sess' /tmp/dav/dav.c:491: error: 'NE_OK' undeclared (first use in this function) /tmp/dav/dav.c:491: error: invalid type argument of '->' /tmp/dav/dav.c: In function 'zif_webdav_copy': /tmp/dav/dav.c:510: error: 'ne_session' undeclared (first use in this function) /tmp/dav/dav.c:510: error: 'sess' undeclared (first use in this function) /tmp/dav/dav.c:511: error: 'ne_request' undeclared (first use in this function) /tmp/dav/dav.c:511: error: 'req' undeclared (first use in this function) /tmp/dav/dav.c:539: error: 'DavSession' has no member named 'sess' /tmp/dav/dav.c:550: error: 'NE_DEPTH_INFINITE' undeclared (first use in this function) /tmp/dav/dav.c:550: error: 'NE_DEPTH_ZERO' undeclared (first use in this function) /tmp/dav/dav.c:554: error: 'NE_OK' undeclared (first use in this function) /tmp/dav/dav.c:554: error: invalid type argument of '->' /tmp/dav/dav.c: In function 'zif_webdav_move': /tmp/dav/dav.c:573: error: 'ne_session' undeclared (first use in this function) /tmp/dav/dav.c:573: error: 'sess' undeclared (first use in this function) /tmp/dav/dav.c:574: error: 'ne_request' undeclared (first use in this function) /tmp/dav/dav.c:574: error: 'req' undeclared (first use in this function) /tmp/dav/dav.c:598: error: 'DavSession' has no member named 'sess' /tmp/dav/dav.c:611: error: 'NE_OK' undeclared (first use in this function) /tmp/dav/dav.c:611: error: invalid type argument of '->' make: *** [dav.lo] Error 1 Any help would be much appreciated. Thanks!

    Read the article

  • Emacs: Define a function which loads the file where the function itself is defined

    - by damd
    I'm refactoring a bit in my Emacs set up and have come to the conclusion that I want to use a different init file than the default one. So basically, in my ~/.emacs file, I have this: (load "/some/directory/init.el") Up until now, that's been working just fine. However, now I want to redefine an old command that I've used for ages, which opens my init file: (defun conf () "Open a buffer with the user init file." (interactive) (find-file user-init-file)) As you can see, this will open ~/.emacs no matter what I do. I want it to open /some/directory/init.el, or wherever the conf command itself is defined. How would I do that?

    Read the article

  • Can any function be a deleted-function?

    - by Caspin
    The working draft explicitly calls out that defaulted-functions must be special member functions (eg copy-constructor, default-constructor, etc). Which makes perfect sense. However, I don't see any such restriction on deleted-functions. Is that right? Or in other words are these three examples valid c++0? struct Foo { // 1 int bar( int ) = delete; }; // 2 int baz( int ) = delete; template< typename T > int boo( T t ); // 3 template<> int boo<int>(int t) = delete;

    Read the article

  • Calling a Function Based on a String Which Contains the Function Name

    - by Phonethics
    var foo1,foo2; switch (fn) { case "fade" : foo1 = "fadeOut"; foo2 = "fadeIn"; break; case "slide" : foo1 = "slideUp"; foo2 = "slideDown"; break; } eval("$('.cls1')." + foo1 + "();"); currentSlideIndex = currentSlideIndex + n; eval("$('.cls1')." + foo2 + "();"); Any better way to achieve this without using eval ? Im not a very big fan of using eval unless absolutely necessary.

    Read the article

< Previous Page | 42 43 44 45 46 47 48 49 50 51 52 53  | Next Page >