Search Results

Search found 62199 results on 2488 pages for 'first order logic'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 90/2488 | < Previous Page | 86 87 88 89 90 91 92 93 94 95 96 97  | Next Page >

  • Change library load order at run time (like LD_PRELOAD but during execution)

    - by tylerl
    How do I change the library a function loads from during run time? For example, say I want to replace the standard printf function with something new, I can write my own version and compile it into a shared library, then put "LD_PRELOAD=/my/library.so" in the environment before running my executable. But let's say that instead, I want to change that linkage from within the program itself. Surely that must be possible... right?

    Read the article

  • Getting the first of a GROUP BY clause in SQL

    - by Michael Bleigh
    I'm trying to implement single-column regionalization for a Rails application and I'm running into some major headaches with a complex SQL need. For this system, a region can be represented by a country code (e.g. us) a continent code that is uppercase (e.g. NA) or it can be NULL indicating the "default" information. I need to group these items by some relevant information such as a foreign key (we'll call it external_id). Given a country and its continent, I need to be able to select only the most specific region available. So if records exist with the country code, I select them. If, not I want a records with the continent code. If not that, I want records with a NULL code so I can receive the default values. So far I've figured that I may be able to use a generated CASE statement to get an arbitrary sort order. Something like this: SELECT *, CASE region WHEN 'us' THEN 1 WHEN 'NA' THEN 2 ELSE 3 END AS region_sort FROM my_table WHERE region IN ('us','NA') OR region IS NULL GROUP BY external_id ORDER BY region_sort The problem is that without an aggregate function the actual data returned by the GROUP BY for a given row seems to be untameable. How can I massage this query to make it return only the first record of the region_sort ordered groups?

    Read the article

  • How to get my first programming job.

    - by itsbunnies
    What is the best way to go about getting your very first programming job? I am currently going to college but have a few years before I graduate. I want to get out of my current "factory" job and into a computer related field as soon as possible. I found quite a few positions that I qualify for, but believe my pathetic resume has hurt me. My resume has a "skills" section where I list everything I am familiar with, but my employment section contains my first job (Super Wash, best car wash around!) and my current job (Assembling stuff that makes up various fans and motors). How do I get a company to give me a chance?

    Read the article

  • Django: order by count of a ForeignKey field?

    - by AP257
    This is almost certainly a duplicate question, in which case apologies, but I've been searching for around half an hour on SO and can't find the answer here. I'm probably using the wrong search terms, sorry. I have a User model and a Submission model. Each Submission has a ForeignKey field called user_submitted for the User who uploaded it. class Submission(models.Model): uploaded_by = models.ForeignKey('User') class User(models.Model): name = models.CharField(max_length=250 ) My question is pretty simple: how can I get a list of the three users with the most Submissions? I trued creating a num_submissions method on the User model: def num_submissions(self): num_submissions = Submission.objects.filter(uploaded_by=self).count() return num_submissions and then doing: top_users = User.objects.filter(problem_user=False).order_by('num_submissions')[:3] but this fails, as do all the other things I've tried. Can I actually do it using a smart database query? Or should I just do something more hacky in the views file?

    Read the article

  • Re-order mysql rows using PHP

    - by dave e
    | id | url | title | menu_id | ------+--------+--------+---------- | 1 | http://| link 1 | 1 | | 2 | http://| link 2 | 2 | | 3 | http://| link 3 | 3 | | 4 | http://| link 4 | 4 | Hi, I was wondering if its possible using PHP to reorder the above to something like below. I am trying to generate a menu which can easily be reordered by clicking an up or down arrow. I have no idea where to start. Any help would be much appreciated. | id | url | title | menu_id | ------+--------+--------+---------- | 1 | http://| link 1 | 2 | | 2 | http://| link 2 | 4 | | 3 | http://| link 3 | 3 | | 4 | http://| link 4 | 1 |

    Read the article

  • Enforcing an "end" call whenever there is a corresponding "start" call

    - by Jeff Meatball Yang
    Let's say I want to enforce a rule: Everytime you call "StartJumping()" in your function, you must call "EndJumping()" before you return. When a developer is writing their code, they may simply forget to call EndSomething - so I want to make it easy to remember. I can think of only one way to do this: and it abuses the "using" keyword: class Jumper : IDisposable { public Jumper() { Jumper.StartJumping(); } public void Dispose() { Jumper.EndJumping(); } public static void StartJumping() {...} public static void EndJumping() {...} } public bool SomeFunction() { // do some stuff // start jumping... using(Jumper j = new Jumper()) { // do more stuff // while jumping } // end jumping } Is there a better way to do this?

    Read the article

  • Prolog: using the sort/2 predicate

    - by Øyvind Hauge
    So I'm trying to get rid of the wrapper clause by using the sort library predicate directly inside split. What split does is just generating a list of numbers from a list that looks like this: [1:2,3:2,4:6] ---split-- [1,2,3,2,4,6]. But the generated list contains duplicates, and I don't want that, so I'm using the wrapper to combine split and sort, which then generates the desired result: [1,2,3,4,6]. I'd really like to get rid of the wrapper and just use sort within split, however I keep getting "ERROR: sort/2: Arguments are not sufficiently instantiated." Any ideas? Thanks :) split([],[]). split([H1:H2|T],[H1,H2|NT]) :- split(T,NT). wrapper(L,Processed) :- split(L,L2), sort(L2,Processed).

    Read the article

  • MongoMapper: how do I create a model like this

    - by Vladimir R
    Suppose we have two models, Task and User. So a user can have many tasks and tasks should be able to have many users too. But, a task should also have a unique creator who is also a user. Exemple: A task in this context is like this: Task ID, Task Creator, Users who should do the task User_1 creates a task and he is then the creator. User_1 specifies User_2 and User_3 as users who should do the task. So these two last users are not creators of task. How do I create this models so that if I have a task object, I can find it's creator and users who should complete it. And how do I do, if I have a user, to find all tasks he created and all tasks he should complete. Thank you.

    Read the article

  • How to append html to first occurance of string after selected element

    - by uku
    Hello, I have html like so: <div class=foo> (<a href=forum.example.com>forum</a>) <p> Some html here.... </div> And I want to insert another link after the first one, like so: <div class=foo> (<a href=forum.example.com>forum</a>) <a href=blog.example.com>blog</a> <p> Some html here.... </div> ...but because it is enclosed in () I cannot use: $('div.foo a:first').append(' <a href=blog.example.com>blog</a>'); ...which would place it before the ). So how can I extend my jQuery selection to select the literal ) or do I need to use another solution?

    Read the article

  • Which style is preferable when writing this boolean expression?

    - by Jeppe Stig Nielsen
    I know this question is to some degree a matter of taste. I admit this is not something I don't understand, it's just something I want to hear others' opinion about. I need to write a method that takes two arguments, a boolean and a string. The boolean is in a sense (which will be obvious shortly) redundant, but it is part of a specification that the method must take in both arguments, and must raise an exception with a specific message text if the boolean has the "wrong" value. The bool must be true if and only if the string is not null or empty. So here are some different styles to write (hopefully!) the same thing. Which one do you find is the most readable, and compliant with good coding practice? // option A: Use two if, repeat throw statement and duplication of message string public void SomeMethod(bool useName, string name) { if (useName && string.IsNullOrEmpty(name)) throw new SomeException("..."); if (!useName && !string.IsNullOrEmpty(name)) throw new SomeException("..."); // rest of method } // option B: Long expression but using only && and || public void SomeMethod(bool useName, string name) { if (useName && string.IsNullOrEmpty(name) || !useName && !string.IsNullOrEmpty(name)) throw new SomeException("..."); // rest of method } // option C: With == operator between booleans public void SomeMethod(bool useName, string name) { if (useName == string.IsNullOrEmpty(name)) throw new SomeException("..."); // rest of method } // option D1: With XOR operator public void SomeMethod(bool useName, string name) { if (!(useName ^ string.IsNullOrEmpty(name))) throw new SomeException("..."); // rest of method } // option D2: With XOR operator public void SomeMethod(bool useName, string name) { if (useName ^ !string.IsNullOrEmpty(name)) throw new SomeException("..."); // rest of method } Of course you're welcome to suggest other possibilities too. Message text "..." would be something like "If 'useName' is true a name must be given, and if 'useName' is false no name is allowed".

    Read the article

  • Using :limit and :order in the associated model

    - by r2b2
    Hello, Is there any way i can limit the results of an associated model? This what i was trying to do : <ul> <% account.logins.slice(0,5).sort_by(&:login_date).reverse.each do |login| -%> <li><%=h login.login_date.strftime("%d.%m.%Y")%></li> <% end -%> </ul> I'm trying to get the last five logins of the account. I cant seem to do it with account.logins(:limit=5) Thanks !

    Read the article

  • Rails find :conditions

    - by Sam
    I have a Reservation model that I'm searching for with three fields. The container_id must always be self.id but as confirmed and auto_confirmed only one needs to be true. I have the following but it doesn't preform what I need: Reservation.find(:all, :conditions => ['container_id = ? AND confirmed = ? OR auto_confirm = ?', self.id, true, true,]) How should I change this?

    Read the article

  • C#: reflection alternative for switch on enum in order to select namespace/class

    - by Am
    Hi, I have an interface named IHarvester. There are 3 implementations of that interface, each under their own namespace: Google Yahoo Bing A HarvesterManager uses the given harvester. It knows the interface and all 3 implementations. I want some way of letting the class user say in which harvester it wants to use. And in the code select that implementation, without a switch-case implementation. Can reflection save my day? Here is the code bits: // repeat for each harvester namespace Harvester.Google { public abstract class Fetcher : BaseHarvester, IInfoHarvester {...} } public enum HarvestingSource { Google, Yahoo, Bing, } class HarvesterManager { public HarvestingSource PreferedSource {get;set;} public HarvestSomthing() { switch (PreferedSource) .... // awful... } } Thanks.

    Read the article

  • Javascript - Canvas image never appears on first function run

    - by Matt
    I'm getting a bit of a weird issue, the image never shows the first time you run the game in your browser, after that you see it every time. If you close your browser and re open it and run the game again, the same issue occurs - you don't see the image the first time you run it. Here's the issue in action, just hit a wall and there's no image the first time on the end game screen. Any help would be appreciated. Regards, Matt function showGameOver() { ctx.clearRect(0, 0, canvas.width, canvas.height); ctx.fillStyle = "black"; ctx.font = "16px sans-serif"; ctx.fillText("Game Over!", ((canvas.width / 2) - (ctx.measureText("Game Over!").width / 2)), 50); ctx.font = "12px sans-serif"; ctx.fillText("Your Score Was: " + score, ((canvas.width / 2) - (ctx.measureText("Your Score Was: " + score).width / 2)), 70); myimage = new Image(); myimage.src = "xcLDp.gif"; var size = [119, 26], //set up size coord = [443, 200]; ctx.font = "12px sans-serif"; ctx.fillText("Restart", ((canvas.width / 2) - (ctx.measureText("Restart").width / 2)), 197); ctx.drawImage( //draw it on canvas myimage, coord[0], coord[1], size[0], size[1] ); $("canvas").click(function(e) { //when click.. if ( testIfOver(this, e, size, coord) ) { startGame(); //reload } }); $("canvas").mousemove(function(e) { //when mouse moving if ( testIfOver(this, e, size, coord) ) { $(this).css("cursor", "pointer"); //change the cursor } else { $(this).css("cursor", "default"); //change it back } }); function testIfOver(ele,ev,size,coord){ if ( ev.pageX > coord[0] + ele.offsetLeft && ev.pageX < coord[0] + size[0] + ele.offsetLeft && ev.pageY > coord[1] + ele.offsetTop && ev.pageY < coord[1] + size[1] + ele.offsetTop ) { return true; } return false; } }

    Read the article

  • CRC function without order dependency

    - by Pirks
    I need a CRC mechanism to calculate the CRC of a number of strings, such that, given two strings, A and B, the sum crc(A) + crc(B) == crc(A+B). P.S. XOR is too weak---the algorithm should be not trivial for reverse engineering.

    Read the article

  • jQuery and first element in the clicked element

    - by user2956944
    i have 2 div elements, and if i click on the first div then should the other div which is inside of the clicked div displayed, but i can't understand who it works, my jquery code is so: jQuery('.infobutton').click(function(){ var clickedID = jQuery(this).attr('id'); jQuery(clickedID).children('div').toggle(); }); <div class="infobutton" id="infobtn1"> <div class="content">some content</div> </div> I get everytime right id, i tried also with .first(), .parent(), .children('.content') It's possible to do this with jQuery?

    Read the article

  • Generate combinations by order and fixed length.

    - by roconmachine
    Suppose there is array main[] = [a,b,c,....z]; a[] = [a1,a2,a3,....] , b[] = [b1,b2,b3,....] and so on. So if we generate combination in main.length of ordered then it looks like ..... a1 b1 c1, a1 b1 c2, a1 b1 c3 ...... a1 b2 c1, a1 b3 c1, ..... a2 b1 c1, a3 b1 c1, ..... and total count will be a.length * b.length * c.length ........ = ? So write a code in any language to generate those combination. all the best. alex

    Read the article

  • Hebbian learning

    - by Bane
    I have asked another question on Hebbian learning before, and I guess I got a good answer which I accepted, but, the problem is that I now realize that I've mistaken about Hebbian learning completely, and that I'm a bit confused. So, could you please explain how it can be useful, and what for? Because the way Wikipedia and some other pages describe it - it doesn't make sense! Why would we want to keep increasing the weight between the input and the output neuron if the fire together? What kind of problems can it be used to solve, because when I simulate it in my head, it certainly can't do the basic AND, OR, and other operations (say you initialize the weights at zero, the output neurons never fire, and the weights are never increased!)

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 86 87 88 89 90 91 92 93 94 95 96 97  | Next Page >