- Boost-users - lists.boost.org

Build program_options using stdcall
by Ben Weatherman 29 Aug '06

29 Aug '06

I want to build the program_options library, but using the stdcall calling convention. Is there a command-line parameter I can pass to bjam that will do this? Thanks in advance, Ben

1 0

bind trouble
by Sebastian Weber 29 Aug '06

29 Aug '06

Hello everybody! I ran into a very weird problem with boost::bind and boost::function. I am using boost 1.33.1 with a g++ 4.0.3 on a Ubuntu dapper system. The code which does not compile is: boost::function< double(double) > pFunc = boost::bind(std::pow, _1, -3); While this code fragment does: double f(double k, double p) { return std::pow(double(k), p); } boost::function< double(std::size_t) > pFunc = boost::bind(f, _1, -3); Ok, I got a solution, but may someone enlighten me what is wrong with the first version? The error message from g++ is correlFunc.cpp: In function 'int main(int, char**)': correlFunc.cpp:184: error: no matching function for call to 'bind(<unknown type>, boost::arg<1>&, double)' Thanks in advance! Greetings, Sebastian Weber

2 1

[Regex] - Is this a limitation of sregex_iterator ?
by kiran 29 Aug '06

29 Aug '06

Hi I am using sregex_iterator to parse an html file like below. string htmlFile; //populate htmlFile with a file contents regex regExpr("Resurfacing(.|\\n)*Home", boost::regex::icase); sregex_iterator itr(htmlFile.begin(), htmlFile.end(), regExpr); But that is throwing and std::runtime_error exception with message "Regular expression too big". What can i do to avoid this ? I went through http://www.boost.org/libs/regex/doc/configuration.html and changed the variables like below #define BOOST_REGEX_NON_RECURSIVE #define BOOST_REGEX_BLOCKSIZE (4096 * 10) #define BOOST_REGEX_MAX_BLOCKS 1024 Even after that i am getting the same error message. I found that when i changed the regular expression ( i mean a simpler 'regExpr' variable) to a simpler one, the exception (std::runtime_error) was not thrown. I need to parse big html files for some complex regular expressions. I dont mind even if the sregex_iterator takes much memory or time.How can i solve this error. ? Or is this a limitatiton of boost::regex library. Thanks In Advance Kiran.

2 2

Mismatch and regex newbie problem still problem
by david v 29 Aug '06

29 Aug '06

Yes i think there were some misunderstanding here.. I think that comes by the definition you have of mistake. A mistake for me is as follows: Regex: "testing" String_to_search: "tastung". The output should be that the regex testing was found but with 2 mismatches that are "a" and "u". So a mismatch is a letter that was not found. It may sound weird to you but the way i'm using the regex is to identify genomic regions, so in other words for biological applications. In some cases my regex is a piece of DNA such as "atgcta" and i want to search for this regex in another piece of DNA. Given the fact that the regex "atgcta" can be found in the genome many times i will get probably get a lot of matches. But in some cases i want to be able to search for "atgcta" but i want to allow some mismatches. Obviuously i will even get more matches but i think regex can be a more much efficient way that by building ip aligment matrices. ANy idea how to handle the example above >-----Original Message----- >From: boost-users-bounces_at_[hidden] [mailto:boost-users- >bounces_at_[hidden]] On Behalf Of david v >Sent: Tuesday, August 29, 2006 9:08 AM >To: boost-users_at_[hidden] >Subject: [Boost-users] Mismatch and regex newbie problem still problem > >So to sum-up. >If the regex i'm looking for is "testing" and the string to search the >regex >for is "tastung" (obviously this is a short example but i'm dealing with >more complex regular expressions. > >how can i get the number of mismatches. Basically the output of the >program >would tell me: > >2 mismatches found in string "tastung" at position 2 (a) and 5(u). [Nat] Maybe I'm completely misunderstanding you. If so, please forgive me. I think you're saying that you want to start with the regex "testing" and have the library detect that the string "tastung" is somehow similar but nonetheless distinct. My belief is that, given the regex "testing", the library will not recognize the string "tastung" in any way. It will simply report that no match was found. You could construct a more complex regex that would handle this particular example. You could, for instance, say that you want to match a "t", followed by an arbitrary character, followed by "st", followed by another arbitrary character, followed by "ng". The library would report that the string "tastung" matches that regex, and you could ask it to tell you the specific substrings matching the variable parts. But if you want to allow arbitrary variance in any character position -- as long as some other set of character positions matches -- then I'm a little perplexed as to how to express that in a regular expression. Maybe an exhaustive family of acceptable alternatives? But if you're dealing with longer expression strings, that could explode really quickly. I think you need to get really specific about the rules you want to use to detect a "mismatch." Then you need to figure out whether the regex library is the right tool to help you apply those rules. Again, sorry if I'm way off base here.

5 4

Mismatch and regex newbie problem still problem"
by david v 29 Aug '06

29 Aug '06

Hello, As James pointed out the right place to start with will be suffix tree algorithms. The only thing i don't know if this is going to be very time consuming ??? ######For Brian.... 1) What's the longest string you're searching for? For the moment is limited to 6 to 8 characters. 2) What's the smallest bit-width of any cpu on which you're running your code? I'm on 64 dual opteron machine 3) How familiar with string searching/matching are you? Quite familiar but was looking for a cpp library that could handle it instead of trying to rewrite things. Best, david

3 2

Re: [Boost-users] Mismatch and regex newbie problem still problem
by Nat Goodspeed 29 Aug '06

29 Aug '06

> -----Original Message----- > From: boost-users-bounces(a)lists.boost.org [mailto:boost-users- > bounces(a)lists.boost.org] On Behalf Of david v > Sent: Tuesday, August 29, 2006 10:02 AM > To: boost-users(a)lists.boost.org > Subject: [Boost-users] Mismatch and regex newbie problem still problem > > It may sound weird to you but the way i'm using the regex is to identify > genomic regions, so in other words for biological applications. > In some cases my regex is a piece of DNA such as "atgcta" and i want to > search for this regex in another piece of DNA. [Nat] That's not weird. I wasn't questioning your desired processing, just trying to figure out where the disconnect lies. > in some cases i want to be able to search for "atgcta" but i > want to allow some mismatches. Obviuously i will even get more matches but > i > think regex can be a more much efficient way that by building ip aligment > matrices. [Nat] This is where you have to get really specific about what kinds of mismatches you want to recognize. For example, will the sequence always begin with "at" and end with "ta" and be separated by exactly two items? ("atxxta") In that case regex is perfect for the problem. If the variable items are at fixed positions within the original pattern, it's easy. But since I don't yet know the full set of cases you intend to allow as a "mismatch," there's room for me to speculate that you might want to find "xtgcta" or "axgcta" or "atxcta" or "atgxta" or "atgcxa" or "atgctx" (one item wrong) or "xxgcta" or "xtxcta" or ... That's for a sequence length of 6. The full list of permutations is so long that you'd want to generate it programmatically. Step up to a length of 7 and that list gets alarmingly longer. That's what I meant when I said that it could quickly explode. How many items must match the original pattern before you recognize a valid "mismatch"? Presumably it's at least 1, otherwise you'd validly "mismatch" every position in every string. In practice, matching only 1 item out of 6 makes little sense to me either. You need to define what does make sense. It may be that regex is still the best tool for the job. But depending on the full set of possibilities that you mean by "mismatch," you might have to hand-code the (mis)match testing instead. I can imagine generating a regex string that would choke the library.

1 0

little endian detection
by Andreas Fabri 29 Aug '06

29 Aug '06

Hello, Is boost supported for Visual C++ 8 in 64 bit mode on XP 64 on an AMD Turion. When I run cl.exe /E boost/detail/endian.hpp I get the error message that it must be set up correctly. I use boost-1_33_1 coming with cygwin. thanks in advance, andreas

2 1

Re: [Boost-users] Mismatch and regex newbie problem still problem
by james.jones＠firstinvestors.com 29 Aug '06

29 Aug '06

From: "david v" <danova_fr(a)hotmail.com> > Yes i think there were some misunderstanding here.. I think that comes by > the definition you have of mistake. A mistake for me is as follows: > > Regex: "testing" > String_to_search: "tastung". > The output should be that the regex testing was found but with 2 mismatches > that are "a" and "u". So a mismatch is a letter that was not found. > > It may sound weird to you but the way i'm using the regex is to identify > genomic regions, so in other words for biological applications. > In some cases my regex is a piece of DNA such as "atgcta" and i want to > search for this regex in another piece of DNA. Given the fact that the regex > "atgcta" can be found in the genome many times i will get probably get a lot > of matches. But in some cases i want to be able to search for "atgcta" but i > want to allow some mismatches. Obviuously i will even get more matches but i > think regex can be a more much efficient way that by building ip aligment > matrices. > > Any idea how to handle the example above I don't see how regex can help you here. You need to use more complicated string algorithms. Try this: http://en.wikipedia.org/wiki/Suffix_tree - James

1 0

Re: [Boost-users] Mismatch and regex newbie problem still problem
by Nat Goodspeed 29 Aug '06

29 Aug '06

> -----Original Message----- > From: boost-users-bounces(a)lists.boost.org [mailto:boost-users- > bounces(a)lists.boost.org] On Behalf Of david v > Sent: Tuesday, August 29, 2006 9:08 AM > To: boost-users(a)lists.boost.org > Subject: [Boost-users] Mismatch and regex newbie problem still problem > > So to sum-up. > If the regex i'm looking for is "testing" and the string to search the > regex > for is "tastung" (obviously this is a short example but i'm dealing with > more complex regular expressions. > > how can i get the number of mismatches. Basically the output of the > program > would tell me: > >2 mismatches found in string "tastung" at position 2 (a) and 5(u). [Nat] Maybe I'm completely misunderstanding you. If so, please forgive me. I think you're saying that you want to start with the regex "testing" and have the library detect that the string "tastung" is somehow similar but nonetheless distinct. My belief is that, given the regex "testing", the library will not recognize the string "tastung" in any way. It will simply report that no match was found. You could construct a more complex regex that would handle this particular example. You could, for instance, say that you want to match a "t", followed by an arbitrary character, followed by "st", followed by another arbitrary character, followed by "ng". The library would report that the string "tastung" matches that regex, and you could ask it to tell you the specific substrings matching the variable parts. But if you want to allow arbitrary variance in any character position -- as long as some other set of character positions matches -- then I'm a little perplexed as to how to express that in a regular expression. Maybe an exhaustive family of acceptable alternatives? But if you're dealing with longer expression strings, that could explode really quickly. I think you need to get really specific about the rules you want to use to detect a "mismatch." Then you need to figure out whether the regex library is the right tool to help you apply those rules. Again, sorry if I'm way off base here.

1 0

Efficiacy of std::vector
by Janos Vegh 29 Aug '06

29 Aug '06

Hi, I was interested in the efficiacy of std::vector. Using the test program below, I receive the following results. The "simple" handling is equivalent with the C array access. The [] and iterator access time of the vector element is an order of magnitude worse, than that of the simple access. This is not because of index limit control, it is done by at() and its use increases that access time by a factor of three. What is going on in the background here, that the implementation is so ineffective? ( I did my tests with WinXP/cygwin/g++/time, using different setting of the #define-s at the beginning) Shall I expect similar ineffectivity with the other STL objects? Regards Janos Empty cycle real 0m2.173s user 0m1.892s sys 0m0.080s STL=1, SIMPLE=1, size=0 real 0m4.917s user 0m4.646s sys 0m0.070s STL=1, size=0 real 0m33.939s user 0m33.658s sys 0m0.090s STL=1, ITERATOR=1, size=1000 real 0m34.059s user 0m33.688s sys 0m0.100s STL=1, AT=1, size=1000 real 1m22.769s user 1m22.368s sys 0m0.090s #define STL 1 #define SIMPLE 0 #define ITERATOR 1 #define AT 0 #define EMPTY 1 #if STL #include <vector> #endif using namespace std; #include <iostream> #define ARR_SIZE 1000 #define CYCLES 1000000 main (int argc, char** argv) { long int i,j,*P; #if EMPTY cout << "Empty cycle"; #else #if STL #if ITERATOR || AT std::vector<long int>::iterator pos; std::vector<long int> arr(ARR_SIZE); #else std::vector <long int> arr; arr.reserve(ARR_SIZE); #endif cout << "STL=1"; #if SIMPLE cout << ", SIMPLE=1"; #endif #if ITERATOR cout << ", ITERATOR=1"; #endif #if AT cout << ", AT=1"; #endif cout << ", size=" << arr.size(); #else long int *arr; arr = new long int[ARR_SIZE]; cout << "STL=0"; #endif #endif cout << endl; #if SIMPLE && STL P = &arr[0]; #endif for(j=0;j<CYCLES; j++) { #if STL && ITERATOR && !EMPTY i = 0; for(pos=arr.begin(); pos < arr.end(); ++pos) { *pos = i; } #else for(i=0; i<ARR_SIZE; i++) { #if !EMPTY #if SIMPLE && STL P[i] = i; #elif STL && AT arr.at(i) = i; #else arr[i] = i; #endif #endif } #endif } exit(0); }

9 10