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  • Find the order among tasks in a company by using prolog?

    - by Cem
    First of all,I wish a happy new year for everyone.I searched more and worked a lot but I could not solve this question.I am quite a new in prolog and I must do this homework. In my homework,the question is like this: Write a prolog program that determines a valid order for the tasks to be carried out in a company. The prolog program will consist of a set of "before" predicates which denotes the order between task pairs. Here is an example; before(a,b). before(a,e). before(d,c). before(b,c). before(c,e). Here, task a should be carried before tasks b and e, d before c and so on. Hence a valid ordering of the tasks would be [a, b, d, c, e]. The order predicate in your program will be queried as follows. ?- order([a,b,c,d,e],X). X = [a, b, d, c, e] ; X = [a, d, b, c, e] ; X = [d, a, b, c, e] ; false. Hint: Try to generate different orders for the tasks (permutation) and then check if the order is consistent with the "before" relationships given. Even if you can generate a single valid order, you will get reasonable partial credits.

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  • Why isn't the eigenclass equivalent to self.class, when it looks so similar?

    - by The Wicked Flea
    I've missed the memo somewhere, and I hope you'll explain this to me. Why is the eigenclass of an object different from self.class? class Foo def initialize(symbol) eigenclass = class << self self end eigenclass.class_eval do attr_accessor symbol end end end My train of logic that equates the eigenclass with class.self is rather simple: class << self is a way of declaring class methods, rather than instance methods. It's a shortcut to def Foo.bar. So within the reference to the class object, returning self should be identical to self.class. This is because class << self would set self to Foo.class for definition of class methods/attributes. Am I just confused? Or, is this a sneaky trick of Ruby meta-programming?

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  • Javascript mouseover image failure

    - by CaptainTeancum
    This is what I have so far, I have been watching a ton of Javascript videos and I feel I mimicked them solid but this is still not functioning as I want. Than being, it changes from logo1 to logo2 on mousover. This is homework. However homework that is important to me so any help or guidance would be appreciated. </head> <body> <p> <div> <script type="text/javascript"> // Pre load images for rollover function imgOver(id) { document.getElementById(id).src="logo1.jpg"; } function imgOut(id) { document.getElementById(id).src="logo2.jpg"; } </script> <a href="#" onmouseover="imgOver('logo1');" onmouseout="imgOut('logo2')"> <img alt="logo" height="150" src="images/Logo1.jpeg" width="110" /> </a> </div> </body> </html>

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  • Phone-book Database Help - Python

    - by IDOntWantThat
    I'm new to programming and have an assignment I've been working at for awhile. I understand defining functions and a lot of the basics but I'm kind of running into a brick wall at this point. I'm trying to figure this one out and don't really understand how the 'class' feature works yet. I'd appreciate any help with this one; also any help with some python resources that have can dummy down how/why classes are used. You've been going to work on a database project at work for sometime now. Your boss encourages you to program the database in Python. You disagree, arguing that Python is not a database language but your boss persists by providing the source code below for a sample telephone database. He asks you to do two things: Evaluate the existing source code and extend it to make it useful for managers in the firm. (You do not need a GUI interface, just work on the database aspects: data entry and retrieval - of course you must get the program to run or properly work He wants you to critically evaluate Python as a database tool. Import the sample code below into the Python IDLE and enhance it, run it and debug it. Add features to make this a more realistic database tool by providing for easy data entry and retrieval. import shelve import string UNKNOWN = 0 HOME = 1 WORK = 2 FAX = 3 CELL = 4 class phoneentry: def __init__(self, name = 'Unknown', number = 'Unknown', type = UNKNOWN): self.name = name self.number = number self.type = type # create string representation def __repr__(self): return('%s:%d' % ( self.name, self.type )) # fuzzy compare or two items def __cmp__(self, that): this = string.lower(str(self)) that = string.lower(that) if string.find(this, that) >= 0: return(0) return(cmp(this, that)) def showtype(self): if self.type == UNKNOWN: return('Unknown') if self.type == HOME: return('Home') if self.type == WORK: return('Work') if self.type == FAX: return('Fax') if self.type == CELL: return('Cellular') class phonedb: def __init__(self, dbname = 'phonedata'): self.dbname = dbname; self.shelve = shelve.open(self.dbname); def __del__(self): self.shelve.close() self.shelve = None def add(self, name, number, type = HOME): e = phoneentry(name, number, type) self.shelve[str(e)] = e def lookup(self, string): list = [] for key in self.shelve.keys(): e = self.shelve[key] if cmp(e, string) == 0: list.append(e) return(list) # if not being loaded as a module, run a small test if __name__ == '__main__': foo = phonedb() foo.add('Sean Reifschneider', '970-555-1111', HOME) foo.add('Sean Reifschneider', '970-555-2222', CELL) foo.add('Evelyn Mitchell', '970-555-1111', HOME) print 'First lookup:' for entry in foo.lookup('reifsch'): print '%-40s %s (%s)' % ( entry.name, entry.number, entry.showtype() ) print print 'Second lookup:' for entry in foo.lookup('e'): print '%-40s %s (%s)' % ( entry.name, entry.number, entry.showtype() ) I'm not sure if I'm on the right track but here is what I have so far: def openPB(): foo = phonedb() print 'Please select an option:' print '1 - Lookup' print '2 - Add' print '3 - Delete' print '4 - Quit' entry=int(raw_input('>> ')) if entry==1: namelookup=raw_input('Please enter a name: ') for entry in foo.lookup(namelookup): print '%-40s %s (%s)' % (entry.name, entry.number, entry.showtype() ) elif entry==2: name=raw_input('Name: ') number=raw_input('Number: ') showtype=input('Type (UNKNOWN, HOME, WORK, FAX, CELL): \n>> ') for entry in foo.add(name, number, showtype): #Trying to figure out this part print '%-40s %s (%s)'% (entry.name, entry.number, entry.showtype() ) elif entry==3: delname=raw_input('Please enter a name to delete: ') # #Trying to figure out this part print "Contact '%s' has been deleted" (delname) elif entry==4: print "Phone book is now closed" quit else: print "Your entry was not recognized." openPB() openPB()

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  • Error data: line 2 column 1 when using pycurl with gzip stream

    - by Sagar Hatekar
    Thanks for reading. Background: I am trying to read a streaming API feed that returns data in JSON format, and then storing this data to a pymongo collection. The streaming API requires a "Accept-Encoding" : "Gzip" header. What's happening: Code fails on json.loads and outputs - Extra data: line 2 column 1 - line 4 column 1 (char 1891 - 5597) (Refer Error Log below) This does NOT happen while parsing every JSON object - it happens at random. My guess is I am encountering some weird JSON object after every "x" proper JSON objects. I did reference how to use pycurl if requested data is sometimes gzipped, sometimes not? and Encoding error while deserializing a json object from Google but so far have been unsuccessful at resolving this error. Could someone please help me out here? Error Log: Note: The raw dump of the JSON object below is basically using the repr() method. '{"id":"tag:search.twitter.com,2005:207958320747782146","objectType":"activity","actor":{"objectType":"person","id":"id:twitter.com:493653150","link":"http://www.twitter.com/Deathnews_7_24","displayName":"Death News 7/24","postedTime":"2012-02-16T01:30:12.000Z","image":"http://a0.twimg.com/profile_images/1834408513/deathnewstwittersquare_normal.jpg","summary":"Crashes, Murders, Suicides, Accidents, Crime and Naturals Death News From All Around World","links":[{"href":"http://www.facebook.com/DeathNews724","rel":"me"}],"friendsCount":56,"followersCount":14,"listedCount":1,"statusesCount":1029,"twitterTimeZone":null,"utcOffset":null,"preferredUsername":"Deathnews_7_24","languages":["tr"]},"verb":"post","postedTime":"2012-05-30T22:15:02.000Z","generator":{"displayName":"web","link":"http://twitter.com"},"provider":{"objectType":"service","displayName":"Twitter","link":"http://www.twitter.com"},"link":"http://twitter.com/Deathnews_7_24/statuses/207958320747782146","body":"Kathi Kamen Goldmark, Writers\xe2\x80\x99 Catalyst, Dies at 63 http://t.co/WBsNlNtA","object":{"objectType":"note","id":"object:search.twitter.com,2005:207958320747782146","summary":"Kathi Kamen Goldmark, Writers\xe2\x80\x99 Catalyst, Dies at 63 http://t.co/WBsNlNtA","link":"http://twitter.com/Deathnews_7_24/statuses/207958320747782146","postedTime":"2012-05-30T22:15:02.000Z"},"twitter_entities":{"urls":[{"display_url":"nytimes.com/2012/05/30/boo\xe2\x80\xa6","indices":[52,72],"expanded_url":"http://www.nytimes.com/2012/05/30/books/kathi-kamen-goldmark-writers-catalyst-dies-at-63.html","url":"http://t.co/WBsNlNtA"}],"hashtags":[],"user_mentions":[]},"gnip":{"language":{"value":"en"},"matching_rules":[{"value":"url_contains: nytimes.com","tag":null}],"klout_score":11,"urls":[{"url":"http://t.co/WBsNlNtA","expanded_url":"http://www.nytimes.com/2012/05/30/books/kathi-kamen-goldmark-writers-catalyst-dies-at-63.html?_r=1"}]}}\r\n{"id":"tag:search.twitter.com,2005:207958321003638785","objectType":"activity","actor":{"objectType":"person","id":"id:twitter.com:178760897","link":"http://www.twitter.com/Mobanu","displayName":"Donald Ochs","postedTime":"2010-08-15T16:33:56.000Z","image":"http://a0.twimg.com/profile_images/1493224811/small_mobany_Logo_normal.jpg","summary":"","links":[{"href":"http://www.mobanuweightloss.com","rel":"me"}],"friendsCount":10272,"followersCount":9698,"listedCount":30,"statusesCount":725,"twitterTimeZone":"Mountain Time (US & Canada)","utcOffset":"-25200","preferredUsername":"Mobanu","languages":["en"],"location":{"objectType":"place","displayName":"Crested Butte, Colorado"}},"verb":"post","postedTime":"2012-05-30T22:15:02.000Z","generator":{"displayName":"twitterfeed","link":"http://twitterfeed.com"},"provider":{"objectType":"service","displayName":"Twitter","link":"http://www.twitter.com"},"link":"http://twitter.com/Mobanu/statuses/207958321003638785","body":"Mobanu: Can Exercise Be Bad for You?: Researchers have found evidence that some people who exercise do worse on ... http://t.co/mTsQlNQO","object":{"objectType":"note","id":"object:search.twitter.com,2005:207958321003638785","summary":"Mobanu: Can Exercise Be Bad for You?: Researchers have found evidence that some people who exercise do worse on ... http://t.co/mTsQlNQO","link":"http://twitter.com/Mobanu/statuses/207958321003638785","postedTime":"2012-05-30T22:15:02.000Z"},"twitter_entities":{"urls":[{"display_url":"nyti.ms/KUmmMa","indices":[116,136],"expanded_url":"http://nyti.ms/KUmmMa","url":"http://t.co/mTsQlNQO"}],"hashtags":[],"user_mentions":[]},"gnip":{"language":{"value":"en"},"matching_rules":[{"value":"url_contains: nytimes.com","tag":null}],"klout_score":12,"urls":[{"url":"http://t.co/mTsQlNQO","expanded_url":"http://well.blogs.nytimes.com/2012/05/30/can-exercise-be-bad-for-you/?utm_medium=twitter&utm_source=twitterfeed"}]}}\r\n' json exception: Extra data: line 2 column 1 - line 4 column 1 (char 1891 - 5597) Header Output: HTTP/1.1 200 OK Content-Type: application/json; charset=UTF-8 Vary: Accept-Encoding Date: Wed, 30 May 2012 22:14:48 UTC Connection: close Transfer-Encoding: chunked Content-Encoding: gzip get_stream.py: #!/usr/bin/env python import sys import pycurl import json import pymongo STREAM_URL = "https://stream.test.com:443/accounts/publishers/twitter/streams/track/Dev.json" AUTH = "userid:passwd" DB_HOST = "127.0.0.1" DB_NAME = "stream_test" class StreamReader: def __init__(self): try: self.count = 0 self.buff = "" self.mongo = pymongo.Connection(DB_HOST) self.db = self.mongo[DB_NAME] self.raw_tweets = self.db["raw_tweets_gnip"] self.conn = pycurl.Curl() self.conn.setopt(pycurl.ENCODING, 'gzip') self.conn.setopt(pycurl.URL, STREAM_URL) self.conn.setopt(pycurl.USERPWD, AUTH) self.conn.setopt(pycurl.WRITEFUNCTION, self.on_receive) self.conn.setopt(pycurl.HEADERFUNCTION, self.header_rcvd) while True: self.conn.perform() except Exception as ex: print "error ocurred : %s" % str(ex) def header_rcvd(self, header_data): print header_data def on_receive(self, data): temp_data = data self.buff += data if data.endswith("\r\n") and self.buff.strip(): try: tweet = json.loads(self.buff, encoding = 'UTF-8') self.buff = "" if tweet: try: self.raw_tweets.insert(tweet) except Exception as insert_ex: print "Error inserting tweet: %s" % str(insert_ex) self.count += 1 if self.count % 10 == 0: print "inserted "+str(self.count)+" tweets" except Exception as json_ex: print "json exception: %s" % str(json_ex) print repr(temp_data) stream = StreamReader()

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  • Moving from wordpress.com to self-hosted wordpress blog

    - by Sarfraz
    Hello, I have been writing articles on the wordpress.com blog, now i am looking to move it to self-hosted wordpress blog but i wonder: 1) Should i move all my articles on the new blog or just put an article on my last blog that more articles will be posted on my new blog?* 2) If i move all articles on my new blog, i am not sure about how google will react to it because there are articles with good number of visitors, won't this be seo-un-friendly because i am not sure but google will re-create page reputation stuff, etc or those articles will have same popularity even if i move elsewhere?* 3) What are the implications and side-effects in moving from wordpress.com blog to self-hosted wordpress blog?* Thanks

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  • Adding a self-signed certificate to iphone Simulator?

    - by jr
    I have a self-signed certificate at the endpoint of my API. I'm trying to test some things using the simulator but am getting "untrusted server certificate". I have tried to use safari on the simulator to download the .crt file, but that doesn't seem to work. Where does iPhone Simulator get its keychain from? How can I add a trusted certificate so my application will work? UPDATE I got it to work by creating a CA and then adding a CA certificate using the iPhone provisioning tool. Then I was able to have a certificate signed by that CA certificate on the API server and the NSConnection just worked. I was not able to get it to work using a self-signed certificate for some reason. I need to re-attempt this using the provisioning software. My real question is how do I get this to work on the simulator? I would think that the simulator uses the keychain of the actual computer.

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  • Eclipse Pydev: Supress no-self errors in python wrappers generated with swig

    - by Christian
    Hi, when generating python wrappers with swig the python wrapper classes in the generated python file do not have an explicit self parameter, for example see below: class PySwigIterator(_object): def value(*args): return _spatiotemporalnmf.PySwigIterator_value(*args) def incr(*args): return _spatiotemporalnmf.PySwigIterator_incr(*args) def decr(*args): return _spatiotemporalnmf.PySwigIterator_decr(*args) def distance(*args): return _spatiotemporalnmf.PySwigIterator_distance(*args) I am developing with the eclipse pluging Pydev. Pydev always shows an error when it detects a method without explicit self parameter. I am aware of two methods to get rid of the errors: First, disable error checking for the whole project in the Pydev preferences. Second, add a #@NoSelf to every line with an error. I don't want to use the first one, because I still want to get error warnings for my non-swig-generated files. Obviously the second one is also not very good, because I would have to do it by hand and every time I generate the file again, all #@NoSelfs will be gone. My Question now is, is there a better way to achieve this? Thanks

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  • How to optimize my PageRank calculation?

    - by asmaier
    In the book Programming Collective Intelligence I found the following function to compute the PageRank: def calculatepagerank(self,iterations=20): # clear out the current PageRank tables self.con.execute("drop table if exists pagerank") self.con.execute("create table pagerank(urlid primary key,score)") self.con.execute("create index prankidx on pagerank(urlid)") # initialize every url with a PageRank of 1.0 self.con.execute("insert into pagerank select rowid,1.0 from urllist") self.dbcommit() for i in range(iterations): print "Iteration %d" % i for (urlid,) in self.con.execute("select rowid from urllist"): pr=0.15 # Loop through all the pages that link to this one for (linker,) in self.con.execute("select distinct fromid from link where toid=%d" % urlid): # Get the PageRank of the linker linkingpr=self.con.execute("select score from pagerank where urlid=%d" % linker).fetchone()[0] # Get the total number of links from the linker linkingcount=self.con.execute("select count(*) from link where fromid=%d" % linker).fetchone()[0] pr+=0.85*(linkingpr/linkingcount) self.con.execute("update pagerank set score=%f where urlid=%d" % (pr,urlid)) self.dbcommit() However, this function is very slow, because of all the SQL queries in every iteration >>> import cProfile >>> cProfile.run("crawler.calculatepagerank()") 2262510 function calls in 136.006 CPU seconds Ordered by: standard name ncalls tottime percall cumtime percall filename:lineno(function) 1 0.000 0.000 136.006 136.006 <string>:1(<module>) 1 20.826 20.826 136.006 136.006 searchengine.py:179(calculatepagerank) 21 0.000 0.000 0.528 0.025 searchengine.py:27(dbcommit) 21 0.528 0.025 0.528 0.025 {method 'commit' of 'sqlite3.Connecti 1 0.000 0.000 0.000 0.000 {method 'disable' of '_lsprof.Profiler 1339864 112.602 0.000 112.602 0.000 {method 'execute' of 'sqlite3.Connec 922600 2.050 0.000 2.050 0.000 {method 'fetchone' of 'sqlite3.Cursor' 1 0.000 0.000 0.000 0.000 {range} So I optimized the function and came up with this: def calculatepagerank2(self,iterations=20): # clear out the current PageRank tables self.con.execute("drop table if exists pagerank") self.con.execute("create table pagerank(urlid primary key,score)") self.con.execute("create index prankidx on pagerank(urlid)") # initialize every url with a PageRank of 1.0 self.con.execute("insert into pagerank select rowid,1.0 from urllist") self.dbcommit() inlinks={} numoutlinks={} pagerank={} for (urlid,) in self.con.execute("select rowid from urllist"): inlinks[urlid]=[] numoutlinks[urlid]=0 # Initialize pagerank vector with 1.0 pagerank[urlid]=1.0 # Loop through all the pages that link to this one for (inlink,) in self.con.execute("select distinct fromid from link where toid=%d" % urlid): inlinks[urlid].append(inlink) # get number of outgoing links from a page numoutlinks[urlid]=self.con.execute("select count(*) from link where fromid=%d" % urlid).fetchone()[0] for i in range(iterations): print "Iteration %d" % i for urlid in pagerank: pr=0.15 for link in inlinks[urlid]: linkpr=pagerank[link] linkcount=numoutlinks[link] pr+=0.85*(linkpr/linkcount) pagerank[urlid]=pr for urlid in pagerank: self.con.execute("update pagerank set score=%f where urlid=%d" % (pagerank[urlid],urlid)) self.dbcommit() This function is 20 times faster (but uses a lot more memory for all the temporary dictionaries) because it avoids the unnecessary SQL queries in every iteration: >>> cProfile.run("crawler.calculatepagerank2()") 64802 function calls in 6.950 CPU seconds Ordered by: standard name ncalls tottime percall cumtime percall filename:lineno(function) 1 0.004 0.004 6.950 6.950 <string>:1(<module>) 1 1.004 1.004 6.946 6.946 searchengine.py:207(calculatepagerank2 2 0.000 0.000 0.104 0.052 searchengine.py:27(dbcommit) 23065 0.012 0.000 0.012 0.000 {meth 'append' of 'list' objects} 2 0.104 0.052 0.104 0.052 {meth 'commit' of 'sqlite3.Connection 1 0.000 0.000 0.000 0.000 {meth 'disable' of '_lsprof.Profiler' 31298 5.809 0.000 5.809 0.000 {meth 'execute' of 'sqlite3.Connectio 10431 0.018 0.000 0.018 0.000 {method 'fetchone' of 'sqlite3.Cursor' 1 0.000 0.000 0.000 0.000 {range} But is it possible to further reduce the number of SQL queries to speed up the function even more?

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  • WCF Integration Facility and Self-Hosted Services

    - by IanT8
    I'm self-hosting several services where I do this to register the service: host = new ServiceHost(typeof(MyService)); host.Open(); Behind the scenes, wcf instantiates my service via the default constructor. Is it possble to use the WCF Integration Facility of Castle Windsor to get WCF to call on Windsor to create the service when I am self-hosting? The example seems shows IIS hosted services where the 1st line of the MyService.svc file looks like: <%@ServiceHost language=c# Debug="true" Service="Microsoft.ServiceModel.Samples.CalculatorService" Factory=WindsorServiceHostFactory%> where presumably a factory is used by wcf to instantiate the service instance.

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  • Regular Expression, JEditorPane, Self-closing tags

    - by Stephen Swensen
    I'm am using JEditorPane to render basic HTML. But it renders self-closing tags incorrectly, specifically br tags, e.g. <br /> is bad but <br> is good. I would like to use String.replaceAll(regex, "<br>") to fix the HTML, where regex is a regular expression matching any self-closing br tag with case-insensitivity and zero to infinity number of spaces between the "r" and the "/" (e.g., <br/>, <BR/>, <br />, <Br     />, etc.). Thanks to any regular expression experts who can solve this!

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  • SQL Self Join Query Help

    - by hdoe123
    Hi All, I'm trying to work out a query that self join itself on a table using the eventnumber. I've never done a self join before. What i'm trying to query is when a client has started off in a city which is chester to see what city they moved to. But I dont want to be able to see if they started off in another city. I would also like be only see the move once (So i'd only like to see if they went from chester to london rather then chester to london to wales) The StartTimeDate is the same EndDateTime if they moved to another city. Data example as follows if they started off in the city chester :- clientid EventNumber City StartDateTime EndDateTime 1 1 Chester 10/03/2009 11/04/2010 13:00 1 1 Liverpool 11/04/2010 13:00 30/06/2010 16:00 1 1 Wales 30/07/2010 16:00 the result I would like to see is on the 2nd row - so it only shows me liverpool. Could anyone point in the right direcetion please?

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  • Creating and releasing objects in the same method, while using self as delegate

    - by user200341
    In objective-c you are responsible for releasing objects you allocate, but what happens when you allocate an object in a method, assign self as the objects delegate, and then release the object. The callbacks from the newly created (and released) object fails at this point, or rather, doesn't happen. - (void)doSomething { MyObj *myObj = [[MyObj alloc] init]; myObj.delegate = self; [myObj performOperation]; [myObj release]; } - (void)callbackMethodFromMyObj:(NSString *)message { NSLog(message); } I can't release the object until the callback has occurred, and I can't avoid releasing the object in the same method that creates it (because it exists outside the scope). One way of doing it would be to pass the object along in the call-back and release it in the callback, but is this the right way to go about this?

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  • Why self.view is not available

    - by amok
    I have this code in the main view controller and it is working just fine and as I wanted. loadingActionSheet = [[UIActionSheet alloc] initWithTitle:@"Posting To Twitter..." delegate:nil cancelButtonTitle:@"Cancel" destructiveButtonTitle:nil otherButtonTitles:nil]; [loadingActionSheet showInView:self.view]; I wanted that code to be reusable from different part of the project so I moved it in a separate file (UIView based). The poblem that I am facing is that self.view is not available there and I don't know why because I am learning and I don't know enough to understand what I am missing. What do I have to do/add/change to have the actionsheet shown in my current view even if that code lives somewhere else?

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  • Changing the context of a self-executing function

    - by TaylorMac
    This code is copied directly from: http://www.bennadel.com/blog/2264-Changing-The-Execution-Context-Of-Your-Self-Executing-Function-Blocks-In-JavaScript.htm // Set the singleton value to the return value of the self- // executing function block. var singleton = (function(){ // Declare a private variable. var message = "Stop playing with your context!"; this.getMessage = function(){ return( message ); }; // Return this object reference. return( this ); }).call( {} ); // alert the singleton message. alert( "Message:", singleton.getMessage()); ?My thought is that I can use this to better contain the variables and functions in my programs. However, when I try to run the code in a JSfiddle: http://jsfiddle.net/xSKHh/ It does not return the message. What am I missing?

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  • Can't get Jacobi algorithm to work in Objective-C

    - by Chris Long
    Hi, For some reason, I can't get this program to work. I've had other CS majors look at it and they can't figure it out either. This program performs the Jacobi algorithm (you can see step-by-step instructions and a MATLAB implementation here). BTW, it's different from the Wikipedia article of the same name. Since NSArray is one-dimensional, I added a method that makes it act like a two-dimensional C array. After running the Jacobi algorithm many times, the diagonal entries in the NSArray (i[0][0], i[1][1], etc.) are supposed to get bigger and the others approach 0. For some reason though, they all increase exponentially. For instance, i[2][4] should equal 0.0000009, not 9999999, while i[2][2] should be big. Thanks in advance, Chris NSArray+Matrix.m @implementation NSArray (Matrix) @dynamic offValue, transposed; - (double)offValue { double sum = 0.0; for ( MatrixItem *item in self ) if ( item.nonDiagonal ) sum += pow( item.value, 2.0 ); return sum; } - (NSMutableArray *)transposed { NSMutableArray *transpose = [[[NSMutableArray alloc] init] autorelease]; int i, j; for ( i = 0; i < 5; i++ ) { for ( j = 0; j < 5; j++ ) { [transpose addObject:[self objectAtRow:j andColumn:i]]; } } return transpose; } - (id)objectAtRow:(NSUInteger)row andColumn:(NSUInteger)column { NSUInteger index = 5 * row + column; return [self objectAtIndex:index]; } - (NSMutableArray *)multiplyWithMatrix:(NSArray *)array { NSMutableArray *result = [[NSMutableArray alloc] init]; int i = 0, j = 0, k = 0; double value; for ( i = 0; i < 5; i++ ) { value = 0.0; for ( j = 0; j < 5; j++ ) { for ( k = 0; k < 5; k++ ) { MatrixItem *firstItem = [self objectAtRow:i andColumn:k]; MatrixItem *secondItem = [array objectAtRow:k andColumn:j]; value += firstItem.value * secondItem.value; } MatrixItem *item = [[MatrixItem alloc] initWithValue:value]; item.row = i; item.column = j; [result addObject:item]; } } return result; } @end Jacobi_AlgorithmAppDelegate.m // ... - (void)jacobiAlgorithmWithEntry:(MatrixItem *)entry { MatrixItem *b11 = [matrix objectAtRow:entry.row andColumn:entry.row]; MatrixItem *b22 = [matrix objectAtRow:entry.column andColumn:entry.column]; double muPlus = ( b22.value + b11.value ) / 2.0; muPlus += sqrt( pow((b22.value - b11.value), 2.0) + 4.0 * pow(entry.value, 2.0) ); Vector *u1 = [[[Vector alloc] initWithX:(-1.0 * entry.value) andY:(b11.value - muPlus)] autorelease]; [u1 normalize]; Vector *u2 = [[[Vector alloc] initWithX:-u1.y andY:u1.x] autorelease]; NSMutableArray *g = [[[NSMutableArray alloc] init] autorelease]; for ( int i = 0; i <= 24; i++ ) { MatrixItem *item = [[[MatrixItem alloc] init] autorelease]; if ( i == 6*entry.row ) item.value = u1.x; else if ( i == 6*entry.column ) item.value = u2.y; else if ( i == ( 5*entry.row + entry.column ) || i == ( 5*entry.column + entry.row ) ) item.value = u1.y; else if ( i % 6 == 0 ) item.value = 1.0; else item.value = 0.0; [g addObject:item]; } NSMutableArray *firstResult = [[g.transposed multiplyWithMatrix:matrix] autorelease]; matrix = [firstResult multiplyWithMatrix:g]; } // ...

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  • untrusted (self-sign) certificate on android browser

    - by Basiclife
    Hi all, Apologies for the brevity of this question but due to an unfortunate series of events, I've managed to brick my PC so am posting from my phone... We've just set up Windows Small Business Server 2008 at work which has an external web portal accessible via HTTPS. We haven't yet bought?installed any certificates. The portal provides access to email, sharepoint, remote desktop, etc.... (I'm aware some of these are never going to work on the phone) From firefox / other desktop browsers, this displays an "untrusted cert' warning which I can choose to ignore. When browsing from my mobile I get a popup notification which says. "A secure connection could not be established" when I OK this (my only option) I see the standard android-generated "unable to load page - has it moved?" Page. Does anyone know of a way to either accept the certificate temporarily or allow untrusted certificates generally? I'm aware that the latter option is non-ideal in the mid to long term but at the moment, I need to access the portal and am willing to either toggle settings as/when required or forego using the mobile for banking, etc... to mitigate my risk. Thanks in advance for any help you can provide and apologies again for brevity In case it helps I'm on the G1 running android 1.6 using the default browser

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  • How do I add a self-referencing linked server in SQL 2008

    - by tigermain
    I am trying to replicate our live server set up local using a single SQL database. In SQL 2005 I would added 2 linked servers both referencing itself with different names, each point to a different table. How do I do this in SQL 2008. I've try the various providers and different parameters butto no avail. The local server is using a trusted connection so I dont need any usernames/passwords Im ideally need to set up the following linked references: DBSVR1 - mydb_master DBSVR2 - mydb_import Any light on the subject would help, I managed to do it in 2005 about 8 months ago but cant remember how, now Im in 2008!

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  • Self-powered USB hub and power supply adapter ampere capacity

    - by galacticninja
    I am looking for a power supply adapter for my USB Hub so it can support at least 2 bus-powered external hard drives. The hub's rating is 5 volts, 2 amperes. I would like to know if it would be OK to buy a power supply adapter rated at less than 2A. I've been looking for power supply adapters and the ones that do support 2A are more expensive (more expensive than the USB hub itself) compared to those that support less than 2A. Will power supply adapter that supports less than 2A (~1-1.5A) work fine to support two external hard drives? The external hard drives are both bus-powered Western Digital My Passport Essentials 250 GB. The OS is Windows XP SP3.

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  • Should EC2 server self register or have admin server

    - by hortitude
    I'm creating AWS servers using chef. I am also planning on enabling auto-scaling. While we have automatic monitoring setup already (server density or nagios etc), I was also going to setup the cloud watch alarm for the status check on the server. This led me down the path of trying to decide whether to install the ec2-command-line tools on the server itself (which then requires me to install java on the servers -- despite no other need for Java in our environment) or to possible have an "admin" box that will check periodically for servers and make sure they have their alarms set. I expect this paradigm to carry over to other things we want to configure (perhaps ensuring that termination protection is setup on production servers?). Any thoughts as to why to go one direction or another?

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  • Adding nodes to MAAS server

    - by Yasith Tharindu
    I was able to install MAAS server using ubuntu 12.04. Then boot up nodes from he PXE. Then installed maas-precise-x86-64-commissioning through pxe. Now the installation is done. but im unable to commission with the MAAS server. It does not show it as a node and neither im unable to add it manually and end up with following error. Also what is the default username password for maas-precise-x86-64-commissioning. Im unable to login. This error when adding node manually. ERROR 2012-11-20 08:32:54,500 maas.maasserver ################################ Exception: timed out ################################ ERROR 2012-11-20 08:32:54,501 maas.maasserver Traceback (most recent call last): File "/usr/lib/python2.7/dist-packages/django/core/handlers/base.py", line 111, in get_response response = callback(request, *callback_args, **callback_kwargs) File "/usr/lib/python2.7/dist-packages/django/views/decorators/vary.py", line 22, in inner_func response = func(*args, **kwargs) File "/usr/lib/python2.7/dist-packages/piston/resource.py", line 166, in call result = self.error_handler(e, request, meth, em_format) File "/usr/lib/python2.7/dist-packages/piston/resource.py", line 164, in call result = meth(request, *args, **kwargs) File "/usr/lib/python2.7/dist-packages/maasserver/api.py", line 251, in dispatcher self, request, request.method, *args, **kwargs) File "/usr/lib/python2.7/dist-packages/maasserver/api.py", line 193, in perform_api_operation return method(handler, request, *args, **kwargs) File "/usr/lib/python2.7/dist-packages/maasserver/api.py", line 493, in new node = create_node(request) File "/usr/lib/python2.7/dist-packages/maasserver/api.py", line 418, in create_node return form.save() File "/usr/lib/python2.7/dist-packages/maasserver/forms.py", line 234, in save node = super(NodeWithMACAddressesForm, self).save() File "/usr/lib/python2.7/dist-packages/django/forms/models.py", line 363, in save fail_message, commit, construct=False) File "/usr/lib/python2.7/dist-packages/django/forms/models.py", line 85, in save_instance instance.save() File "/usr/lib/python2.7/dist-packages/maasserver/models.py", line 114, in save return super(CommonInfo, self).save(*args, **kwargs) File "/usr/lib/python2.7/dist-packages/django/db/models/base.py", line 460, in save self.save_base(using=using, force_insert=force_insert, force_update=force_update) File "/usr/lib/python2.7/dist-packages/django/db/models/base.py", line 570, in save_base created=(not record_exists), raw=raw, using=using) File "/usr/lib/python2.7/dist-packages/django/dispatch/dispatcher.py", line 172, in send response = receiver(signal=self, sender=sender, **named) File "/usr/lib/python2.7/dist-packages/maasserver/provisioning.py", line 485, in provision_post_save_Node profile, power_type, preseed_data) File "/usr/lib/python2.7/dist-packages/maasserver/provisioning.py", line 245, in call result = self.method(*args) 259,1 93% result = self.method(*args) File "/usr/lib/python2.7/xmlrpclib.py", line 1224, in call return self._send(self._name, args) File "/usr/lib/python2.7/xmlrpclib.py", line 1578, in _request verbose=self._verbose File "/usr/lib/python2.7/xmlrpclib.py", line 1264, in request return self.single_request(host, handler, request_body, verbose) File "/usr/lib/python2.7/xmlrpclib.py", line 1294, in single_request response = h.getresponse(buffering=True) File "/usr/lib/python2.7/httplib.py", line 1030, in getresponse response.begin() File "/usr/lib/python2.7/httplib.py", line 407, in begin version, status, reason = self._read_status() File "/usr/lib/python2.7/httplib.py", line 365, in _read_status line = self.fp.readline() File "/usr/lib/python2.7/socket.py", line 447, in readline data = self._sock.recv(self._rbufsize) timeout: timed out

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