Search Results

Search found 4919 results on 197 pages for 'integer'.

Page 176/197 | < Previous Page | 172 173 174 175 176 177 178 179 180 181 182 183 | Next Page >

C++ : Declaring the array size with a non-constant variable

- by Jérôme

I always thought that when declaring an array in C++, the size has to be a constant integer value. For instance : int MyArray[5]; // correct or const int ARRAY_SIZE = 6; int MyArray[ARRAY_SIZE]; // correct but int ArraySize = 5; int MyArray[ArraySize]; // incorrect Here is also what is explained in The C++ Programming Language, by Bjarne Stroustrup : The number of elements of the array, the array bound, must be a constant expression (§C.5). If you need variable bounds, use a vector(§3.7.1, §16.3). For example: void f(int i) { int v1[i]; // error : array size not a constant expression vector<int> v2[i]; // ok } But to my big surprise, the code above does compile fine on my system ! Here is what I tried to compile : void f(int i) { int v2[i]; } int main() { int i = 3; int v1[i]; f(5); } I got no error ! I'm using GCC v4.4.0. Is there something I'm missing ?

Read the article
Data Structure / Hash Function to link Sets of Ints to Value

- by Gaminic

Given n integer id's, I wish to link all possible sets of up to k id's to a constant value. What I'm looking for is a way to translate sets (e.g. {1, 5}, {1, 3, 5} and {1, 2, 3, 4, 5, 6, 7}) to unique values. Guarantees: n < 100 and k < 10 (again: set sizes will range in [1, k]). The order of id's doesn't matter: {1, 5} == {5, 1}. All combinations are possible, but some may be excluded. All sets and values are constant and made only once. No deletes or inserts, no value updates. Once generated, the only operations taking place will be look-ups. Look-ups will be frequent and one-directional (given set, look up value). There is no need to sort (or otherwise organize) the values. Additionally, it would be nice (but not obligatory) if "neighboring" sets (drop one id, add one id, swap one id, etc) are easy to reach, as well as "all sets that include at least this set". Any ideas?

Read the article
Optimize INSERT / UPDATE / DELETE operation

- by clime

I wonder if the following script can be optimized somehow. It does write a lot to disk because it deletes possibly up-to-date rows and reinserts them. I was thinking about applying something like "insert ... on duplicate key update" and found some possibilities for single-row updates but I don't know how to apply it in the context of INSERT INTO ... SELECT query. CREATE OR REPLACE FUNCTION update_member_search_index() RETURNS VOID AS $$ DECLARE member_content_type_id INTEGER; BEGIN member_content_type_id := (SELECT id FROM django_content_type WHERE app_label='web' AND model='member'); DELETE FROM watson_searchentry WHERE content_type_id = member_content_type_id; INSERT INTO watson_searchentry (engine_slug, content_type_id, object_id, object_id_int, title, description, content, url, meta_encoded) SELECT 'default', member_content_type_id, web_member.id, web_member.id, web_member.name, '', web_user.email||' '||web_member.normalized_name||' '||web_country.name, '', '{}' FROM web_member INNER JOIN web_user ON (web_member.user_id = web_user.id) INNER JOIN web_country ON (web_member.country_id = web_country.id) WHERE web_user.is_active=TRUE; END; $$ LANGUAGE plpgsql; EDIT: Schemas of web_member, watson_searchentry, web_user, web_country: http://pastebin.com/3tRVPPVi. (content_type_id, object_id_int) in watson_searchentry is unique pair in the table but atm the index is not present (there is no use for it). This script should be run at most once a day for full rebuilds of search index.

Read the article
JSON can't read, key reading fail maybe

- by Abdullah Al Mubarok

I wonder why I can't read the JSON Object like this : { "1":{"bulan":"Januari","tahun":"2012","tagihan":"205000","status":"Lunas"}, "2":{"bulan":"Februari","tahun":"2012","tagihan":"180000","status":"Lunas"}, "3":{"bulan":"Maret","tahun":"2012","tagihan":"120000","status":"Lunas"}, "4":{"bulan":"April","tahun":"2012","tagihan":"230000","status":"Lunas"}, "5":{"bulan":"Mei","tahun":"2012","tagihan":"160000","status":"Lunas"}, "6":{"bulan":"Juni","tahun":"2012","tagihan":"150000","status":"Belum Lunas"}, "panjang":6 } with my android code like this : try { int length = jobj.getInt("panjang"); for(int n = 0; n < length; n++){ String m = Integer.toString(n) JSONObject row = jobj.getJSONObject(m); String bulan = row.getString("bulan"); String tahun = row.getString("tahun"); String tagihan = row.getString("tagihan"); String status = row.getString("status"); HashMap<String, String> map = new HashMap<String, String>(); map.put("bulan", bulan); map.put("tahun", tahun); map.put("tagihan", tagihan); map.put("status", status); list.add(map); } } catch (JSONException e) { e.printStackTrace(); } It always return nothing, but it works fine if I change the key m to specific key like if String m = "1"; and I can't use JSONObject row = jobj.getJSONObject(n); because getJSONObject() just accept string, not int. is there something wrong with my code?

Read the article
Grouping by date, with 0 when count() yields no lines

- by SCO

I'm using Postgresql 9 and I'm fighting with counting and grouping when no lines are counted. Let's assume the following schema : create table views { date_event timestamp with time zone ; event_id integer; } Let's imagine the following content : 2012-01-01 00:00:05 2 2012-01-01 01:00:05 5 2012-01-01 03:00:05 8 2012-01-01 03:00:15 20 I want to group by hour, and count the number of lines. I wish I could retrieve the following : 2012-01-01 00:00:00 1 2012-01-01 01:00:00 1 2012-01-01 02:00:00 0 2012-01-01 03:00:00 2 2012-01-01 04:00:00 0 2012-01-01 05:00:00 0 . . 2012-01-07 23:00:00 0 I mean that for each time range slot, I count the number of lines in my table whose date correspond, otherwise, I return a line with a count at zero. The following will definitely not work (will yeld only lines with counted lines 0). SELECT extract ( hour from date_event ),count(*) FROM views where date_event > '2012-01-01' and date_event <'2012-01-07' GROUP BY extract ( hour from date_event ); Please note I might also need to group by minute, or by hour, or by day, or by month, or by year (multiple queries is possible of course). I can only use plain old sql, and since my views table can be very big (100M records), I try to keep performance in mind. How can this be achieved ? Thank you !

Read the article
LINQ Sorting - First three need to be different manufacturers

- by Rob

My OM has a 'product' object. Each product has a 'manufacturer id' (property, integer). When I have a list of products to display, the first three are displayed as the 'featured products'. The list is already sorted in a specific sort order, putting the 'featured' products first in the list. However, I now need to ensure the featured products in the listing are from different Manufacturers. I want to have a method to call to do this re-sorting. Trying to utilize LINQ to to the querying of the input 'products' and the 'results' public List<Product> SetFeatures(List<Product> products, int numberOfFeatures) { List<Product> result; // ensure the 2nd product is different manufacturer than the first .... // ensure the 3rd product is a different manufacturer than the first two... // ... etc ... for the numberOfFeatures return result; } Thanks in advance.

Read the article
Include Multiple Labels and change the value of the same in Iphone, Objective C

- by user576569

I m trying to insert label in each row of the cell. Displaying integer. and I m trying to increase the quantity if user click on button add or minus I able to insert button in UITableView Cell as well the function to change the value. But when I click on add button it changes value only for the last row and not on the specific row. //MY code to insert label in each cell txtQty = [[UILabel alloc] initWithFrame:CGRectMake(233,7,20,20)]; txtQty.text = [NSString stringWithFormat:@"%@",[nos objectAtIndex:indexPath.row]]; txtQty.tag = count; txtQty.textColor =[UIColor whiteColor]; txtQty.backgroundColor = [UIColor clearColor]; [cell.contentView addSubview:txtQty]; //Button Creation UIButton *button2 = [[UIButton alloc] initWithFrame:CGRectMake(180,5,30,30)]; [button2 addTarget:self action:@selector(subAddSubQty:) forControlEvents:UIControlEventTouchUpInside]; [button2 setTag:count]; [cell.contentView addSubview:button2]; now what happening is suppose there are 3 rows in table and I click on the 1st row add button the value gets change in the last label i.e at 3rd row and not of the 1st row How to solve these?? please help Thank You

Read the article
How to implement instance numbering?

- by Joan Venge

I don't know if the title is clear but basically I am trying to implement something like this: public class Effect { public int InternalId ... public void ResetName() ... } When ResetName is called, this will reset the name of the object to: "Effect " + someIndex; So if I have 5 instances of Effect, they will be renamed to: "Effect 1" "Effect 2" "Effect 3" ... So I have another method (ResetNames) in another manager/container type that calls ResetName for each instance. And right now I have to pass an integer to ResetName while keeping a counter myself inside ResetNames. But this feels not as clean and this prevents me from calling ResetName myself outside the manager class, which is valid. How to do this better/cleaner? As for the InternalId, it's just some id that stores the creation order for everything. So I can't just rely on these, because the numbers are large, like 32000, etc. EDIT: Container ResetNames code: int count = 1; var effects = this.Effects.OrderBy ( n => n.InternalId ); foreach ( Effect effect in effects ) { effect.ResetName ( count ); ++count; }

Read the article
PHP - Patterns within Arrays

- by Toby

I am trying to create a function which maps a recurring pattern of integers using an array. As an example if I have a starting array of (0,1,3) and I know that I want to stop the pattern when I hit 15. The pattern gets incremented by a fixed integer each time (lets say 4) so my final pattern should be.. 0 1 3 4 (0 + 4) 5 (1 + 4) 7 (2 + 4) 8 (4 + 4) 9 (5 + 4) 11(7 + 4) 12(8 + 4) 13(9 + 4) 15(11+ 4) Does anyone have any pointers on how this can be achieved? My current implementation works but is stupidly inefficient which something like this... $array = array(0,1,3); $inc = 4; $end = end($array); $final = 15; while($end < $final) { $tmp = array(); foreach($array AS $row) { $tmp = $row + $inc; } $array = merge($tmp, $array); $end = end($array); }

Read the article
Heapsort not working in Python for list of strings using heapq module

- by VSN

I was reading the python 2.7 documentation when I came across the heapq module. I was interested in the heapify() and the heappop() methods. So, I decided to write a simple heapsort program for integers: from heapq import heapify, heappop user_input = raw_input("Enter numbers to be sorted: ") data = map (int, user_input.split(",")) new_data = [] for i in range(len(data)): heapify(data) new_data.append(heappop(data)) print new_data This worked like a charm. To make it more interesting, I thought I would take away the integer conversion and leave it as a string. Logically, it should make no difference and the code should work as it did for integers: from heapq import heapify, heappop user_input = raw_input("Enter numbers to be sorted: ") data = user_input.split(",") new_data = [] for i in range(len(data)): heapify(data) print data new_data.append(heappop(data)) print new_data Note: I added a print statement in the for loop to see the heapified list. Here's the output when I ran the script: `$ python heapsort.py Enter numbers to be sorted: 4, 3, 1, 9, 6, 2 [' 1', ' 3', ' 2', ' 9', ' 6', '4'] [' 2', ' 3', '4', ' 9', ' 6'] [' 3', ' 6', '4', ' 9'] [' 6', ' 9', '4'] [' 9', '4'] ['4'] [' 1', ' 2', ' 3', ' 6', ' 9', '4']` The reasoning I applied was that since the strings are being compared, the tree should be the same if they were numbers. As is evident, the heapify didn't work correctly after the third iteration. Could someone help me figure out if I am missing something here? I'm running Python 2.4.5 on RedHat 3.4.6-9. Thanks, VSN

Read the article
how do I use an enum value on a switch statement in C++

- by BotBotPgm

I would like to use an enum value for my switch statment in C++. Is it possible to use the enum values enclosed in the "{}" as choices for the "switch()"? I know that switch() needs an integer value in order to direct the flow of programming to the appropriate case number. If this is the case, do I just make a variable for each constant in the 'enum' statment? I also want the user to be able to pick the choice and pass that choice to the switch() statement. for example: cout<< "1 - Easy"; cout<<"2 - Medium"; cout<< "3 -Hard"; enum myChoice {EASY =1 ,MEDIUM = 2, HARD = 3} cin ???? switch(????) case 1/EASY: (can I just type case EAST?) cout << "You picked easy!"; break; case 2/MEDIUM: cout << "You picked medium!"; case 3..... (same thing as case 2 except on hard.) default: return 0; Thanks

Read the article
What is a more "ruby way" to write this code?

- by steadfastbuck

This was a homework assignment for my students (I am a teaching assistant) in c and I am trying to learn Ruby, so I thought I would code it up. The goal is to read integers from a redirected file and print some simple information. The first line in the file is the number of elements, and then each integer resides on its own line. This code works (although perhaps inefficiently), but how can I make the code more Ruby-like? #!/usr/bin/ruby -w # first line is number of inputs (Don't need it) num_inputs = STDIN.gets.to_i # read inputs as ints h = Hash.new STDIN.each do |n| n = n.to_i h[n] = 1 unless h[n] and h[n] += 1 end # find smallest mode h.sort.each do |k,v| break puts "Mode is: #{k}", "\n" if v == h.values.max end # mode unique? v = h.values.sort print "Mode is unique: " puts v.pop == v.pop, "\n" # print number of singleton odds, # odd elems repeated odd number times in desc order # even singletons in desc order odd_once = 0 odd = Array.new even = Array.new h.each_pair do |k, v| odd_once += 1 if v == 1 and k.odd? odd << k if v.odd? even << k if v == 1 and k.even? end puts "Number of elements with an odd value that appear only once: #{odd_once}", "\n" puts "Elements repeated an odd number of times:" puts odd.sort.reverse, "\n" puts "Elements with an even value that appear exactly once:" puts even.sort.reverse, "\n" # print fib numbers in the hash class Fixnum def is_fib? l, h = 0, 1 while h <= self return true if h == self l, h = h, l+h end end end puts "Fibonacci numbers:" h.keys.sort.each do |n| puts n if n.is_fib? end

Read the article
C/C++ Bit Array or Bit Vector

- by MovieYoda

Hi, I am learning C/C++ programming & have encountered the usage of 'Bit arrays' or 'Bit Vectors'. Am not able to understand their purpose? here are my doubts - Are they used as boolean flags? Can one use int arrays instead? (more memory of course, but..) What's this concept of Bit-Masking? If bit-masking is simple bit operations to get an appropriate flag, how do one program for them? is it not difficult to do this operation in head to see what the flag would be, as apposed to decimal numbers? I am looking for applications, so that I can understand better. for Eg - Q. You are given a file containing integers in the range (1 to 1 million). There are some duplicates and hence some numbers are missing. Find the fastest way of finding missing numbers? For the above question, I have read solutions telling me to use bit arrays. How would one store each integer in a bit?

Read the article
Rails - Beginner wants feedback on how they've modeled their app and how to do it better.

- by adam

I think the way I've modelled my app is a bit fishy and i need to rejig things, im just not sure how. I've already re-jigged and refactored before. It took a long time ( I'm a beginner ) and I'm hesitant to it again in case i head off in the wrong direction again. Basic Idea, user can submit an answer, another user can mark it correct or incorrect. If incorrect they have to write the correct answer. Users can view their and everybody else's correct and incorrect answers. So I did it this way class Answer has_one: correction end class Correction belongs_to :answer end when a user marks an answer as correct, I set checked_at:DateTime and checked_by_id:integer on the Answer object to keep track of who checked the answer and when. For incorrect answers I create a correction object which holds the correct answer and again checked_by and checked_at details. I don't like this because I have checked_by and checked_at in both models. It just doesn't sit right. Possible solutions are: Create a third model such as VerifiedAnswer and move the checked_by/at attributes to that. It will handle the situtation where an answer is marked correct. Or are these models thin enough (they dont have any other attributes) that I can just have one model ( Answer ) that has all the attributes to store all this information?

Read the article
syntax for MySQL INSERT with an array of columns

- by Mike_Laird

I'm new to PHP and MySQL query construction. I have a processor for a large form. A few fields are required, most fields are user optional. In my case, the HTML ids and the MySQL column names are identical. I've found tutorials about using arrays to convert $_POST into the fields and values for INSERT INTO, but I can't get them working - after many hours. I've stepped back to make a very simple INSERT using arrays and variables, but I'm still stumped. The following line works and INSERTs 5 items into a database with over 100 columns. The first 4 items are strings, the 5th item, monthlyRental is an integer. $query = "INSERT INTO `$table` (country, stateProvince, city3, city3Geocode, monthlyRental) VALUES ( '$country', '$stateProvince', '$city3', '$city3Geocode', '$monthlyRental')"; When I make an array for the fields and use it, as follows: $colsx = array('country,', 'stateProvince,', 'city3,', 'city3Geocode,', 'monthlyRental'); $query = "INSERT INTO `$table` ('$colsx') VALUES ( '$country', '$stateProvince', '$city3', '$city3Geocode', '$monthlyRental')"; I get a MySQL error - check the manual that corresponds to your MySQL server version for the right syntax to use near ''Array') VALUES ( 'US', 'New York', 'Fairport, Monroe County, New York', '(43.09)' at line 1. I get this error whether the array items have commas inside the single quotes or not. I've done a lot of reading and tried many combinations and I can't get it. I want to see the proper syntax on a small scale before I go back to foreach expressions to process $_POST and both the fields and values are arrays. And yes, I know I should use mysql_real_escape_string, but that is an easy later step in the foreach. Lastly, some clues about the syntax for an array of values would be helpful, particularly if it is different from the fields array. I know I need to add a null as the first array item to trigger the MySQL autoincrement id. What else? I'm pretty new, so please be specific.

Read the article
[Ruby On Rails] belongs_to with :class_name option fails.

- by crackpot

I have no idea what went wrong but I can't get belongs_to work with :class_name option. Could somebody enlighten me. Thanks a lot! Here is a snip from my code. class CreateUsers < ActiveRecord::Migration def self.up create_table :users do |t| t.text :name end end def self.down drop_table :users end end ##################################################### class CreateBooks < ActiveRecord::Migration def self.up create_table :books do |t| t.text :title t.integer :author_id, :null => false end end def self.down drop_table :books end end ##################################################### class User < ActiveRecord::Base has_many: books end ##################################################### class Book < ActiveRecord::Base belongs_to :author, :class_name => 'User', :validate => true end ##################################################### class BooksController < ApplicationController def create user = User.new({:name => 'John Woo'}) user.save @failed_book = Book.new({:title => 'Failed!', :author => @user}) @failed_book.save # missing author_id @success_book = Book.new({:title => 'Nice day', :author_id => @user.id}) @success_book.save # no error! end end environment: ruby 1.9.1-p387 Rails 2.3.5

Read the article
Cannot locate record in delphi ADO query

- by Danatela

I can't locate any record in TADOQuery using PK. First, I was trying to use standard Locate method: PPUQuery.Locate('ID', SpPlansQuery['PPONREC'], []); It always returns False, but manual search (passing the whole query matching ID with given PPONREC which is really slow) finds the desired row. I tried using loPartialKey and switched CursorLocation of query to clUseServer, but it didn't help. Next, I tried to filter my PPUQuery: PPUQuery.Filter := 'ID = ' + VarToStr(SpPlansQuery['PPONREC']); PPUQuery.Filtered := True; PPUQuery.First; But after that the PPUQuery.Eof is True and PPUQuery.RecordCount equals 0. Underlying database is Oracle 9 and the ID is of type INTEGER and is PK of table TPORDER_CMK. PPUQuery.SQL is: SELECT tp.*, la.*, lm.*, ld.*, ld1.*, to_cmk.* FROM ppu_plan.tporder_cmk tp JOIN PPU_PLAN.LARTICLES la ON TP.ARTICLE = LA.ID JOIN PPU_PLAN.LMATERIAL lm ON TP.MATERIAL = lm.id JOIN PPU_PLAN.LCADEP ld ON TP.CADEP = LD.ID JOIN PPU_PLAN.LCADEP ld1 ON TP.PRODUCER = LD1.ID JOIN PPU_PLAN.TORDER_CMK to_cmk ON TP.order_id=TO_cmk.ID WHERE TP.PLAN_ID = :pplan_id What should I try next and how to solve this problem?

Read the article
Proc causing a random TypeError

- by go____yourself

I'm refactoring some code and this proc is causing an error randomly and I don't know why or how to debug it... Any ideas? New code with proc defense_moves, offense_moves = [], [] determine_move = ->move,side,i { side << move.count(move[i]) } defense.size.times { |i| determine_move.(defense, defense_moves, i) } offense.size.times { |i| determine_move.(offense, offense_moves, i) } dm = defense[defense_moves.index(defense_moves.max)].nil? ? [0] : defense[defense_moves.index(defense_moves.max)] om = offense[offense_moves.index(offense_moves.max)].nil? ? [0] : offense[offense_moves.index(offense_moves.max)] Original code: d = 0 defense_moves = [] loop do defense_moves << defense.count(defense[d]) break if defense.count(defense[d]).zero? d += 1 end o = 0 offense_moves = [] loop do offense_moves << offense.count(offense[o]) break if offense.count(offense[o]).zero? o += 1 end dm = defense[defense_moves.index(defense_moves.max)].nil? ? [0] : defense[defense_moves.index(defense_moves.max)] om = offense[offense_moves.index(offense_moves.max)].nil? ? [0] : offense[offense_moves.index(offense_moves.max)] TypeError ttt2.rb:95:in `[]': no implicit conversion from nil to integer (TypeError) from ttt2.rb:95:in `computer_make_move' from ttt2.rb:133:in `draw_board' from ttt2.rb:24:in `place' from ttt2.rb:209:in `block in start_new_game' from ttt2.rb:188:in `loop' from ttt2.rb:188:in `start_new_game' from ttt2.rb:199:in `block in start_new_game' from ttt2.rb:188:in `loop' from ttt2.rb:188:in `start_new_game' from ttt2.rb:199:in `block in start_new_game' from ttt2.rb:188:in `loop' from ttt2.rb:188:in `start_new_game' from ttt2.rb:199:in `block in start_new_game' from ttt2.rb:188:in `loop' from ttt2.rb:188:in `start_new_game' from ttt2.rb:199:in `block in start_new_game' from ttt2.rb:188:in `loop' from ttt2.rb:188:in `start_new_game' from ttt2.rb:234:in `<main>'

Read the article
jQuery ajax request response is empty in Internet Explorer

- by Aprilia1982

Hi, I'm doing the following ajax call: //exif loader function LoadExif(cImage) { $.ajax({ type: "POST", url: "http://localhost:62414/Default1.aspx/GetImageExif", data: "{iCurrentImage:" + cImage + "}", contentType: "application/json; charset=utf-8", dataType: "json", error: ajaxFailed, success: function (data, status) { var sStr = ''; for (var count in data.d) { sStr = sStr + data.d[count]; }; alert(sStr); } }); }; In Firefox the request works really fine. When I try to run the code in Internet Explorer, the response is empty. Here is the webmethod witch is called: <WebMethod()> _ <ScriptMethod(ResponseFormat:=ResponseFormat.Json)> _ Public Shared Function GetImageExif(ByVal iCurrentImage As Integer) As String Dim sbTable As New StringBuilder sbTable.AppendLine("<table>") sbTable.AppendLine("<tr>") sbTable.AppendLine("<td>Name</td><td>" & gGallery.Images(iCurrentImage).File.Name & "</td>") sbTable.AppendLine("</tr>") sbTable.AppendLine("</table>") Return sbTable.ToString End Function Any ideas? Jan

Read the article
Saving a Record with Rails Association

- by tshauck

Hi, I've been going through the Rails Guides, but have gotten stuck on associations after going through validations and migrations. So, I have the following models Job and Person, where a Person can have many jobs. I know that in reality there'd be a many-to-many, but I'm trying to get my handle on this first. class Job < ActiveRecord::Base belongs_to :people end and class Person < ActiveRecord::Base has_many :jobs end Here's the schema ActiveRecord::Schema.define(:version => 20110108185924) do create_table "jobs", :force => true do |t| t.string "occupation" t.boolean "like" t.datetime "created_at" t.datetime "updated_at" t.integer "person_id" end create_table "people", :force => true do |t| t.string "first_name" t.string "last_name" t.datetime "created_at" t.datetime "updated_at" end end Is there some I can do the following j = Job.first; j.Person? Then that'd give me access to the Person object associated with the j. I couldn't find it on guides.rubyonrails.org, although it has been very helpful getting a grip on migrations and validations thus far. Thanks PS, If there are any tutorials that covers more of this kind of things links would be great.

Read the article
Abstract away a compound identity value for use in business logic?

- by John K

While separating business logic and data access logic into two different assemblies, I want to abstract away the concept of identity so that the business logic deals with one consistent identity without having to understand its actual representation in the data source. I've been calling this a compound identity abstraction. Data sources in this project are swappable and various and the business logic shouldn't care which data source is currently in use. The identity is the toughest part because its implementation can change per kind of data source, whereas other fields like name, address, etc are consistently scalar values. What I'm searching for is a good way to abstract the concept of identity, whether it be an existing library, a software pattern or just a solid good idea of some kind is provided. The proposed compound identity value would have to be comparable and usable in the business logic and passed back to the data source to specify records, entities and/or documents to affect, so the data source must be able to parse back out the details of its own compound ids. Data Source Examples: This serves to provide an idea of what I mean by various data sources having different identity implementations. A relational data source might express a piece of content with an integer identifier plus a language specific code. For example. content_id language Other Columns expressing details of content 1 en_us 1 fr_ca The identity of the first record in the above example is: 1 + en_us However when a NoSQL data source is substituted, it might somehow represent each piece of content with a GUID string 936DA01F-9ABD-4d9d-80C7-02AF85C822A8 plus language code of a different standardization, And a third kind of data source might use just a simple scalar value. So on and so forth, you get the idea.

Read the article
An Array returned by a model association is not an Array?

- by Warren

We have a model association that looks something like this: class Example < ActiveRecord::Base has_many :others, :order => 'others.rank' end The rank column is an integer type. The details of these particular models are not really important though as we have found the same problem with other has_many associations between other models. We have also added to the Enumerable module: module Enumerable def method_missing(name) super unless name.to_s[0..7] == 'collect_' method = name.to_s[8..-1] collect{|element| element.send(method)} end end This adds a collect_id method that we can use to get an array of record ids from an array of ActiveRecord objects. So if we use a normal ActiveRecord find :all, we get a nice array which we can then use collect_id on but if we use Example.others.collect_id, we get NoMethodError: undefined method `collect_id' for #<Class:0x2aaaac0060a0> Example.others.class returns "Array" so is it lying or confused? Our solution thus far has been to use it this way: Example.others.to_a.collect_id This works but this seems a bit strange. Why would you have to do that? We are on Ruby 1.8.7 and Rails 2.3.4

Read the article
Fastest method to define whether a number is a triangular number

- by psihodelia

A triangular number is the sum of the n natural numbers from 1 to n. What is the fastest method to find whether a given positive integer number is a triangular one? I suppose, there must be a hidden pattern in a binary representation of such numbers (like if you need to find whether a number is even/odd you check its least significant bit). Here is a cut of the first 1200th up to 1300th triangular numbers, you can easily see a bit-pattern here (if not, try to zoom out): (720600, '10101111111011011000') (721801, '10110000001110001001') (723003, '10110000100000111011') (724206, '10110000110011101110') (725410, '10110001000110100010') (726615, '10110001011001010111') (727821, '10110001101100001101') (729028, '10110001111111000100') (730236, '10110010010001111100') (731445, '10110010100100110101') (732655, '10110010110111101111') (733866, '10110011001010101010') (735078, '10110011011101100110') (736291, '10110011110000100011') (737505, '10110100000011100001') (738720, '10110100010110100000') (739936, '10110100101001100000') (741153, '10110100111100100001') (742371, '10110101001111100011') (743590, '10110101100010100110') (744810, '10110101110101101010') (746031, '10110110001000101111') (747253, '10110110011011110101') (748476, '10110110101110111100') (749700, '10110111000010000100') (750925, '10110111010101001101') (752151, '10110111101000010111') (753378, '10110111111011100010') (754606, '10111000001110101110') (755835, '10111000100001111011') (757065, '10111000110101001001') (758296, '10111001001000011000') (759528, '10111001011011101000') (760761, '10111001101110111001') (761995, '10111010000010001011') (763230, '10111010010101011110') (764466, '10111010101000110010') (765703, '10111010111100000111') (766941, '10111011001111011101') (768180, '10111011100010110100') (769420, '10111011110110001100') (770661, '10111100001001100101') (771903, '10111100011100111111') (773146, '10111100110000011010') (774390, '10111101000011110110') (775635, '10111101010111010011') (776881, '10111101101010110001') (778128, '10111101111110010000') (779376, '10111110010001110000') (780625, '10111110100101010001') (781875, '10111110111000110011') (783126, '10111111001100010110') (784378, '10111111011111111010') (785631, '10111111110011011111') (786885, '11000000000111000101') (788140, '11000000011010101100') (789396, '11000000101110010100') (790653, '11000001000001111101') (791911, '11000001010101100111') (793170, '11000001101001010010') (794430, '11000001111100111110') (795691, '11000010010000101011') (796953, '11000010100100011001') (798216, '11000010111000001000') (799480, '11000011001011111000') (800745, '11000011011111101001') (802011, '11000011110011011011') (803278, '11000100000111001110') (804546, '11000100011011000010') (805815, '11000100101110110111') (807085, '11000101000010101101') (808356, '11000101010110100100') (809628, '11000101101010011100') (810901, '11000101111110010101') (812175, '11000110010010001111') (813450, '11000110100110001010') (814726, '11000110111010000110') (816003, '11000111001110000011') (817281, '11000111100010000001') (818560, '11000111110110000000') (819840, '11001000001010000000') (821121, '11001000011110000001') (822403, '11001000110010000011') (823686, '11001001000110000110') (824970, '11001001011010001010') (826255, '11001001101110001111') (827541, '11001010000010010101') (828828, '11001010010110011100') (830116, '11001010101010100100') (831405, '11001010111110101101') (832695, '11001011010010110111') (833986, '11001011100111000010') (835278, '11001011111011001110') (836571, '11001100001111011011') (837865, '11001100100011101001') (839160, '11001100110111111000') (840456, '11001101001100001000') (841753, '11001101100000011001') (843051, '11001101110100101011') (844350, '11001110001000111110') For example, can you also see a rotated normal distribution curve, represented by zeros between 807085 and 831405?

Read the article
Variable Scoping in a method and its persistence in C++

- by de costo

Consider the following public method that adds an integer variable to a vector of ints(private member) in a class in C++. KoolMethod() { int x; x = 10; KoolList.Add(x); } Vector<int>KoolList; But is this a valid addition to a vector ??? Upon calling the method, it creates a local variable. The scope of this local variable ends the moment the execution control leaves the method. And since this local variable is allocated on a stack(on the method call), any member of KoolList points to an invalid memory location in deallocated stack which may or may not contain the expected value of x. Is this an accurate description of above mechanism ?? Is there a need for creating an int in heap storage using "new" operator everytime a value needs to be added to the vector like described below ????: KoolMethod() { int *x = new int(); *x = 10; KoolList.Add(x); } Vector<int*>KoolList;

Read the article
How to factorize common tags with nokogiri builder ?

- by plafoucriere

Hi, I'd like to create several builders, with common tags, in order to have xml docs like : <xml version="1.0"?> <a_kind_of_root>  <event_date>20100514</event_date> <event_id>123</event_id> <event_type>Conference</event_type>  <my_tag>some text</my_tag> </a_kind_of_root> </xml> <xml version="1.0"?> <another_kind_of_root>  <event_date>20100514</event_date> <event_id>123</event_id> <event_type>Conference</event_type>  <my_other_tag>some integer</my_other_tag> </another_kind_of_root> </xml> I don't know how to put the common part inside a Nokogiri::XML::Builder Thanks

Read the article

< Previous Page | 172 173 174 175 176 177 178 179 180 181 182 183 | Next Page >