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  • how to substract numbers from levels

    - by romunov
    Dear SOFers, I would like to cut a vector of values ranging 0-70 to x number of categories, and would like the upper limit of each category. So far, I have tried this using cut() and am trying to extract the limits from levels. I have a list of levels, from which I would like to extract the second number from each level. How can I extract the values between space and ] (which is the number I'm interested in)? I have: > levels(bins) [1] "(-0.07,6.94]" "(6.94,14]" "(14,21]" "(21,28]" "(28,35]" [6] "(35,42]" "(42,49]" "(49,56]" "(56,63.1]" "(63.1,70.1]" and would like to get: [1] 6.94 14 21 28 35 42 49 56 63.1 70.1 Or is there a better way of calculating the upper bounds of categories?

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  • IP address numbers in MySQL subquery

    - by Iain Collins
    I have a problem with a subquery involving IPV4 addresses stored in MySQL (MySQL 5.0). The IP addresses are stored in two tables, both in network number format - e.g. the format output by MySQL's INET_ATON(). The first table ('events') contains lots of rows with IP addresses associated with them, the second table ('network_providers') contains a list of provider information for given netblocks. events table (~4,000,000 rows): event_id (int) event_name (varchar) ip_address (unsigned 4 byte int) network_providers table (~60,000 rows): ip_start (unsigned 4 byte int) ip_end (unsigned 4 byte int) provider_name (varchar) Simplified for the purposes of the problem I'm having, the goal is to create an export along the lines of: event_id,event_name,ip_address,provider_name If do a query along the lines of either of the following, I get the result I expect: SELECT provider_name FROM network_providers WHERE INET_ATON('192.168.0.1') >= network_providers.ip_start ORDER BY network_providers.ip_start DESC LIMIT 1 SELECT provider_name FROM network_providers WHERE 3232235521 >= network_providers.ip_start ORDER BY network_providers.ip_start DESC LIMIT 1 That is to say, it returns the correct provider_name for whatever IP I look up (of course I'm not really using 192.168.0.1 in my queries). However, when performing this same query as a subquery, in the following manner, it doesn't yield the result I would expect: SELECT event.id, event.event_name, (SELECT provider_name FROM network_providers WHERE event.ip_address >= network_providers.ip_start ORDER BY network_providers.ip_start DESC LIMIT 1) as provider FROM events Instead the a different (incorrect) value for network_provider is returned - over 90% (but curiously not all) values returned in the provider column contain the wrong provider information for that IP. Using event.ip_address in a subquery just to echo out the value confirms it contains the value I'd expect and that the subquery can parse it. Replacing event.ip_address with an actual network number also works, just using it dynamically in the subquery in this manner that doesn't work for me. I suspect the problem is there is something fundamental and important about subqueries in MySQL that I don't get. I've worked with IP addresses like this in MySQL quite a bit before, but haven't previously done lookups for them using a subquery. The question: I'd really appreciate an example of how I could get the output I want, and if someone here knows, some enlightenment as to why what I'm doing doesn't work so I can avoid making this mistake again. Notes: The actual real-world usage I'm trying to do is considerably more complicated (involving joining two or three tables). This is a simplified version, to avoid overly complicating the question. Additionally, I know I'm not using a between on ip_start & ip_end - that's intentional (the DB's can be out of date, and such cases the owner in the DB is almost always in the next specified range and 'best guess' is fine in this context) however I'm grateful for any suggestions for improvement that relate to the question. Efficiency is always nice, but in this case absolutely not essential - any help appreciated.

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  • How can I search for numbers in a varchar column

    - by dave
    I've got a simple nvarchar(25) column in an SQL database table. Most of the time, this field should contain alphanumeric text. However, due to operator error, there are many instances where it contains only a number. Can I do a simple search in SQL to identify these cases? That is, determine which rows in the table contain only digits in this column. As an extension, could I also search for those column values which contain only digits and a space and/or slash. In other languages (eg. Perl, Java) a regular expression would resolve this quickly and easily. But I haven't been able to find the equivalent in SQL.

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  • Designing small comparable objects

    - by Thomas Ahle
    Intro Consider you have a list of key/value pairs: (0,a) (1,b) (2,c) You have a function, that inserts a new value between two current pairs, and you need to give it a key that keeps the order: (0,a) (0.5,z) (1,b) (2,c) Here the new key was chosen as the average between the average of keys of the bounding pairs. The problem is, that you list may have milions of inserts. If these inserts are all put close to each other, you may end up with keys such to 2^(-1000000), which are not easily storagable in any standard nor special number class. The problem How can you design a system for generating keys that: Gives the correct result (larger/smaller than) when compared to all the rest of the keys. Takes up only O(logn) memory (where n is the number of items in the list). My tries First I tried different number classes. Like fractions and even polynomium, but I could always find examples where the key size would grow linear with the number of inserts. Then I thought about saving pointers to a number of other keys, and saving the lower/greater than relationship, but that would always require at least O(sqrt) memory and time for comparison. Extra info: Ideally the algorithm shouldn't break when pairs are deleted from the list.

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  • Linenumber for Exception thrown in runtime-compiled DotNET code

    - by David Rutten
    Not quite the same as this thread, but pretty close. My program allows people to enter some VB or C# code which gets compiled, loaded and executed at runtime. My CompilerParams are: CompilerParameters params = new CompilerParameters(); params.GenerateExecutable = false; params.GenerateInMemory = true; params.IncludeDebugInformation = false; params.TreatWarningsAsErrors = false; params.WarningLevel = 4; When this code throws an exception I'd like to be able to display a message box that helps users debug their code. The exception message is easy, but the line-number is where I got stuck. I suspect that in order to get at the line number, I may need to drastically change the CompilerParameters and perhaps even the way these dlls get stored/loaded. Does anyone know the least steps needed to get this to work?

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  • Trying to reduce the speed overhead of an almost-but-not-quite-int number class

    - by Fumiyo Eda
    I have implemented a C++ class which behaves very similarly to the standard int type. The difference is that it has an additional concept of "epsilon" which represents some tiny value that is much less than 1, but greater than 0. One way to think of it is as a very wide fixed point number with 32 MSBs (the integer parts), 32 LSBs (the epsilon parts) and a huge sea of zeros in between. The following class works, but introduces a ~2x speed penalty in the overall program. (The program includes code that has nothing to do with this class, so the actual speed penalty of this class is probably much greater than 2x.) I can't paste the code that is using this class, but I can say the following: +, -, +=, <, > and >= are the only heavily used operators. Use of setEpsilon() and getInt() is extremely rare. * is also rare, and does not even need to consider the epsilon values at all. Here is the class: #include <limits> struct int32Uepsilon { typedef int32Uepsilon Self; int32Uepsilon () { _value = 0; _eps = 0; } int32Uepsilon (const int &i) { _value = i; _eps = 0; } void setEpsilon() { _eps = 1; } Self operator+(const Self &rhs) const { Self result = *this; result._value += rhs._value; result._eps += rhs._eps; return result; } Self operator-(const Self &rhs) const { Self result = *this; result._value -= rhs._value; result._eps -= rhs._eps; return result; } Self operator-( ) const { Self result = *this; result._value = -result._value; result._eps = -result._eps; return result; } Self operator*(const Self &rhs) const { return this->getInt() * rhs.getInt(); } // XXX: discards epsilon bool operator<(const Self &rhs) const { return (_value < rhs._value) || (_value == rhs._value && _eps < rhs._eps); } bool operator>(const Self &rhs) const { return (_value > rhs._value) || (_value == rhs._value && _eps > rhs._eps); } bool operator>=(const Self &rhs) const { return (_value >= rhs._value) || (_value == rhs._value && _eps >= rhs._eps); } Self &operator+=(const Self &rhs) { this->_value += rhs._value; this->_eps += rhs._eps; return *this; } Self &operator-=(const Self &rhs) { this->_value -= rhs._value; this->_eps -= rhs._eps; return *this; } int getInt() const { return(_value); } private: int _value; int _eps; }; namespace std { template<> struct numeric_limits<int32Uepsilon> { static const bool is_signed = true; static int max() { return 2147483647; } } }; The code above works, but it is quite slow. Does anyone have any ideas on how to improve performance? There are a few hints/details I can give that might be helpful: 32 bits are definitely insufficient to hold both _value and _eps. In practice, up to 24 ~ 28 bits of _value are used and up to 20 bits of _eps are used. I could not measure a significant performance difference between using int32_t and int64_t, so memory overhead itself is probably not the problem here. Saturating addition/subtraction on _eps would be cool, but isn't really necessary. Note that the signs of _value and _eps are not necessarily the same! This broke my first attempt at speeding this class up. Inline assembly is no problem, so long as it works with GCC on a Core i7 system running Linux!

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  • excel turning my numbers to floats

    - by femi
    Hello, i have a bit of asp.net code that exports data in a datagrid into excel but i noticed that it messes up a particular field when exporting. eg .. i have the value of something like 89234010000725515875 in a column in the datagrid but when exported, it turns it into 89234+19. Is there any excel formatting that will bring back my original number? thanks

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  • Find a repeated numbers out of 3 boxes

    - by james1
    I have 3 boxes, each box contain 10 piece of numbered paper (1 - 10) but there is a number the same in all 3 boxes eg: box1 has number 4 and box2 has number 4 and box3 also has number 4. How to find that repeated number in java with an efficient/fastest way possible?

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  • Looking for interesing formula

    - by Thinker
    I'm creating a game, where players can make an alloy. To make it less predictable, and more interesting, I thought that durability and hardness of an alloy can't be calculated by simple formula, because it will be extremely easy to find extrema, where alloy have best statistics. So the questions is, is there any formula for a function, where extrema can be found only by investigating all points? Input values will be in percents: 0.0%-100.0%. I think, it should look like this: half sound wave

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  • More efficient comparison of numbers

    - by Pez Cuckow
    I have an array which is part of a small JS game I am working on I need to check (as often as reasonable) that each of the elements in the array haven't left the "stage" or "playground", so I can remove them and save the script load I have coded the below and was wondering if anyone knew a faster/more efficient way to calculate this. This is run every 50ms (it deals with the movement). Where bots[i][1] is movement in X and bots[i][2] is movement in Y (mutually exclusive). for (var i in bots) { var left = parseInt($("#" + i).css("left")); var top = parseInt($("#" + i).css("top")); var nextleft = left + bots[i][1]; var nexttop = top + bots[i][2]; if(bots[i][1]>0&&nextleft>=PLAYGROUND_WIDTH) { remove_bot(i); } else if(bots[i][1]<0&&nextleft<=-GRID_SIZE) { remove_bot(i); } else if(bots[i][2]>0&&nexttop>=PLAYGROUND_HEIGHT) { remove_bot(i); } else if(bots[i][2]<0&&nexttop<=-GRID_SIZE) { remove_bot(i); } else { //alert(nextleft + ":" + nexttop); $("#" + i).css("left", ""+(nextleft)+"px"); $("#" + i).css("top", ""+(nexttop)+"px"); } } On a similar note the remove_bot(i); function is as below, is this correct (I can't splice as it changes all the ID's of the elements in the array. function remove_bot(i) { $("#" + i).remove(); bots[i] = false; } Many thanks for any advice given!

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  • Thread-safty of boost RNG

    - by Maciej Piechotka
    I have a loop which should be nicely pararellized by insering one openmp pragma: boost::normal_distribution<double> ddist(0, pow(retention, i - 1)); boost::variate_generator<gen &, BOOST_TYPEOF(ddist)> dgen(rng, ddist); // Diamond const std::uint_fast32_t dno = 1 << i - 1; // #pragma omp parallel for for (std::uint_fast32_t x = 0; x < dno; x++) for (std::uint_fast32_t y = 0; y < dno; y++) { const std::uint_fast32_t diff = size/dno; const std::uint_fast32_t x1 = x*diff, x2 = (x + 1)*diff; const std::uint_fast32_t y1 = y*diff, y2 = (y + 1)*diff; double avg = (arr[x1][y1] + arr[x1][y2] + arr[x2][y1] + arr[x2][y2])/4; arr[(x1 + x2)/2][(y1 + y2)/2] = avg + dgen(); } (unless I make an error each execution does not depend on others at all. Sorry that not all of code is inserted). However my question is - are boost RNG thread-safe? They seems to refer to gcc code for gcc so even if gcc code is thread-safe it may not be the case for other platforms.

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  • Storing float numbers as strings in android database

    - by sandis
    So I have an app where I put arbitrary strings in a database and later extract them like this: Cursor DBresult = myDatabase.query(false, Constant.DATABASE_NOTES_TABLE_NAME, new String[] {"myStuff"}, where, null, null, null, null, null); DBresult.getString(0); This works fine in all cases except for when the string looks like a float number, for example "221.123123123". After saving it to the database I can extract the database to my computer and look inside it with a DB-viewer, and the saved number is correct. However, when using cursor.getString() the string "221.123" is returned. I cant for the life of me understand how I can prevent this. I guess I could do a cursor.getDouble() on every single string to see if this gives a better result, but that feels sooo ugly and inefficient. Any suggestions? Cheers, edit: I just made a small test program. This program prints "result: 123.123", when I would like it to print "result: 123.123123123" SQLiteDatabase database = openOrCreateDatabase("databas", Context.MODE_PRIVATE, null); database.execSQL("create table if not exists tabell (nyckel string primary key);"); ContentValues value = new ContentValues(); value.put("nyckel", "123.123123123"); database.insert("tabell", null, value); Cursor result = database.query("tabell", new String[]{"nyckel"}, null, null, null, null, null); result.moveToFirst(); Log.d("TAG","result: " + result.getString(0));

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  • multi-shop orders table and sequential order numbers based on shop

    - by imanc
    Hey, I am looking at building a shop solution that needs to be scalable. Currently it retrieves 1-2000 orders on average per day across multiple country based shops (e.g. uk, us, de, dk, es etc.) but this order could be 10x this amount in two years. I am looking at either using separate country-shop databases to store the orders tables, or looking to combine all into one order table. If all orders exist in one table with a global ID (auto num) and country ID (e.g uk,de,dk etc.), each countries orders would also need to have sequential ordering. So in essence, we'd have to have a global ID and a country order ID, with the country order ID being sequential for countries only, e.g. global ID = 1000, country = UK, country order ID = 1000 global ID = 1001, country = DE, country order ID = 1000 global ID = 1002, country = DE, country order ID = 1001 global ID = 1003, country = DE, country order ID = 1002 global ID = 1004, country = UK, country order ID = 1001 THe global ID would be DB generated and not something I would need to worry about. But I am thinking that I'd have to do a query to get the current country order based ID+1 to find the next sequential number. Two things concern me about this: 1) query times when the table has potentially millions of rows of data and I'm doing a read before a write, 2) the potential for ID number clashes due to simultaneous writes/reads. With a MyISAM table the entire table could be locked whilst the last country order + 1 is retrieved, to prevent ID number clashes. I am wondering if anyone knows of a more elegant solution? Cheers, imanc

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  • How to get arc4Sin() output into label/NSString

    - by Moshe
    I'm trying to take the output of arc4sin and put it into a label. (EDIT: You can ignore this and just post sample code, if this is too irrelevant.) I've tried: // Implement viewDidLoad to do additional setup after loading the view, typically from a nib. - (void)viewDidLoad { [super viewDidLoad]; NSString *number = [[NSString alloc] stringWithFormat: @"%@", arc4random() % 9]; label.text = number; } I've created an IBOutlet for "label" and connected it. What's wrong here?

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  • how to fadein LI elements randomly? (jquery)

    - by user366123
    Hi ive got a set of li with hover effect, what i want is when the page loads ALL the li fadein randomly. i don't want to shuffle them.....they should keep their ordering intact meaning 1,2,3,4,5.... just want to make them appear on the page randomly and stay there test page: http://humayunrehman.com/hovertest/

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  • Rounding values up or down in C#

    - by c11ada
    Hey all, I've created a game which gives a score at the end of the game, but the problem is that this score is sometimes a number with a lot of digits after the decimal point (like 87.124563563566). How would I go about rounding up or down the value so that I could have something like 87.12? Thanks!

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  • Algorithm for assigning a unique series of bits for each user?

    - by Mark
    The problem seems simple at first: just assign an id and represent that in binary. The issue arises because the user is capable of changing as many 0 bits to a 1 bit. To clarify, the hash could go from 0011 to 0111 or 1111 but never 1010. Each bit has an equal chance of being changed and is independent of other changes. What would you have to store in order to go from hash - user assuming a low percentage of bit tampering by the user? I also assume failure in some cases so the correct solution should have an acceptable error rate. I would an estimate the maximum number of bits tampered with would be about 30% of the total set. I guess the acceptable error rate would depend on the number of hashes needed and the number of bits being set per hash. I'm worried with enough manipulation the id can not be reconstructed from the hash. The question I am asking I guess is what safe guards or unique positioning systems can I use to ensure this happens.

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  • Java Regex for matching hexadecimal numbers in a file

    - by Ranman
    So I'm reading in a file (like java program < trace.dat) which looks something like this: 58 68 58 68 40 c 40 48 FA If I'm lucky but more often it has several whitespace characters before and after each line. These are hexadecimal addresses that I'm parsing and I basically need to make sure that I can get the line using a scanner, buffered reader... whatever and make sure I can then convert the hexadecimal to an integer. This is what I have so far: Scanner scanner = new Scanner(System.in); int address; String binary; Pattern pattern = Pattern.compile("^\\s*[0-9A-Fa-f]*\\s*$", Pattern.CASE_INSENSITIVE); while(scanner.hasNextLine()) { address = Integer.parseInt(scanner.next(pattern), 16); binary = Integer.toBinaryString(address); //Do lots of other stuff here } //DO MORE STUFF HERE... So I've traced all my errors to parsing input and stuff so I guess I'm just trying to figure out what regex or approach I need to get this working the way I want.

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  • How can I stop cruise control re-building after a failed build?

    - by RodeoClown
    I got back from the weekend to discover that somebody *ahem* had missed a file commit last thing Friday afternoon... Cruise control has been having fun, and tried to re-build every five minutes since then despite no further commits. This means that my colleagues and I have received approximately six hojillion emails from cruise control. A single fail email would be more than enough to notify us. Is there any way to stop cruise control building on failure, at least until a new commit occurs?

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