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  • Excel or OpenOffice Table Summary: how to reconstruct a table from another, with "missing" values

    - by Gilberto
    I have a table of values (partial) with 3 columns: month (from 1 to 12), code and value. E.g., MONTH | CODE | VALUE 1 | aaa | 111 1 | bbb | 222 1 | ccc | 333 2 | aaa | 1111 2 | ccc | 2222 The codes are clients and the values are sales volumes. Each row represents the sales for one month for one client. So I have three clients, namely aaa, bbb, and ccc. For month=1 their sales volumes are: aaa-111, bbb-222, and ccc-333. A client may or may not have sales for every month; for example, for the month 2, the client bbb has no sales. I have to construct a completed summary table for all the MONTH / CODE pairs with their corresponding VALUE (using the value from the "partial" table, if present, otherwise print a string "missing"). MONTH | CODE | VALUE 1 | aaa | 111 1 | bbb | 222 1 | ccc | 333 2 | aaa | 1111 2 | bbb | missing 2 | ccc | 2222 Or, to put it another way, the table is a linear representation of a matrix:                                 and I want to identify the cells for which no value was provided. How can I do that?

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  • Trying to understand the usage of class_eval

    - by eMxyzptlk
    Hello everyone, I'm using the rails-settings gem, and I'm trying to understand how you add functions to ActiveRecord classes (I'm building my own library for card games), and I noticed that this gem uses one of the Meta-programming techniques to add the function to the ActiveRecord::Base class (I'm far from Meta-programming master in ruby, but I'm trying to learn it) module RailsSettings class Railtie < Rails::Railtie initializer 'rails_settings.initialize', :after => :after_initialize do Railtie.extend_active_record end end class Railtie def self.extend_active_record ActiveRecord::Base.class_eval do def self.has_settings class_eval do def settings RailsSettings::ScopedSettings.for_thing(self) end scope :with_settings, :joins => "JOIN settings ON (settings.thing_id = #{self.table_name}.#{self.primary_key} AND settings.thing_type = '#{self.base_class.name}')", :select => "DISTINCT #{self.table_name}.*" scope :with_settings_for, lambda { |var| { :joins => "JOIN settings ON (settings.thing_id = #{self.table_name}.#{self.primary_key} AND settings.thing_type = '#{self.base_class.name}') AND settings.var = '#{var}'" } } scope :without_settings, :joins => "LEFT JOIN settings ON (settings.thing_id = #{self.table_name}.#{self.primary_key} AND settings.thing_type = '#{self.base_class.name}')", :conditions => 'settings.id IS NULL' scope :without_settings_for, lambda { |var| { :joins => "LEFT JOIN settings ON (settings.thing_id = #{self.table_name}.#{self.primary_key} AND settings.thing_type = '#{self.base_class.name}') AND settings.var = '#{var}'", :conditions => 'settings.id IS NULL' } } end end end end end end What I don't understand is why he uses class_eval on ActiveRecord::Base, wasn't it easier if he just open the ActiveRecord::Base class and define the functions? Specially that there's nothing dynamic in the block (What I mean by dynamic is when you do class_eval or instance_eval on a string containing variables) something like this: module ActiveRecord class Base def self.has_settings class_eval do def settings RailsSettings::ScopedSettings.for_thing(self) end scope :with_settings, :joins => "JOIN settings ON (settings.thing_id = #{self.table_name}.#{self.primary_key} AND settings.thing_type = '#{self.base_class.name}')", :select => "DISTINCT #{self.table_name}.*" scope :with_settings_for, lambda { |var| { :joins => "JOIN settings ON (settings.thing_id = #{self.table_name}.#{self.primary_key} AND settings.thing_type = '#{self.base_class.name}') AND settings.var = '#{var}'" } } scope :without_settings, :joins => "LEFT JOIN settings ON (settings.thing_id = #{self.table_name}.#{self.primary_key} AND settings.thing_type = '#{self.base_class.name}')", :conditions => 'settings.id IS NULL' scope :without_settings_for, lambda { |var| { :joins => "LEFT JOIN settings ON (settings.thing_id = #{self.table_name}.#{self.primary_key} AND settings.thing_type = '#{self.base_class.name}') AND settings.var = '#{var}'", :conditions => 'settings.id IS NULL' } } end end end end I understand the second class_eval (before the def settings) is to define functions on the fly on every class that 'has_settings' right ? Same question here, I think he could use "def self.settings" instead of "class_eval.... def settings", no ?

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  • How to force mdadm to stop RAID5 array?

    - by lucek
    I have /dev/md127 RAID5 array that consisted of four drives. I managed to hot remove them from the array and currently /dev/md127 does not have any drives: cat /proc/mdstat Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] md0 : active raid1 sdd1[0] sda1[1] 304052032 blocks super 1.2 [2/2] [UU] md1 : active raid0 sda5[1] sdd5[0] 16770048 blocks super 1.2 512k chunks md127 : active raid5 super 1.2 level 5, 512k chunk, algorithm 2 [4/0] [____] unused devices: <none> and mdadm --detail /dev/md127 /dev/md127: Version : 1.2 Creation Time : Thu Sep 6 10:39:57 2012 Raid Level : raid5 Array Size : 8790402048 (8383.18 GiB 9001.37 GB) Used Dev Size : 2930134016 (2794.39 GiB 3000.46 GB) Raid Devices : 4 Total Devices : 0 Persistence : Superblock is persistent Update Time : Fri Sep 7 17:19:47 2012 State : clean, FAILED Active Devices : 0 Working Devices : 0 Failed Devices : 0 Spare Devices : 0 Layout : left-symmetric Chunk Size : 512K Number Major Minor RaidDevice State 0 0 0 0 removed 1 0 0 1 removed 2 0 0 2 removed 3 0 0 3 removed I've tried to do mdadm --stop /dev/md127 but: mdadm --stop /dev/md127 mdadm: Cannot get exclusive access to /dev/md127:Perhaps a running process, mounted filesystem or active volume group? I made sure that it's unmounted, umount -l /dev/md127 and confirmed that it indeed is unmounted: umount /dev/md127 umount: /dev/md127: not mounted I've tried to zero superblock of each drive and I get (for each drive): mdadm --zero-superblock /dev/sde1 mdadm: Unrecognised md component device - /dev/sde1 Here's output of lsof|grep md127: lsof|grep md127 md127_rai 276 root cwd DIR 9,0 4096 2 / md127_rai 276 root rtd DIR 9,0 4096 2 / md127_rai 276 root txt unknown /proc/276/exe What else can I do? LVM is not even installed so it can't be a factor.

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  • php dom problem

    - by Guru
    hello I'm new to PHP programming and I migrated from ASP .net to PHP.. I have a div just like below <div id="mydiv"></div> what I wanted to do is just to change the text and html content(like some name or any data in it) in it. What I imagine is just like mydiv=innertext="some value"; Thanks, GURU

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  • c++ try catch practices

    - by Tony
    Is this considered good programming practise in C++: try { // some code } catch(someException) { // do something } catch (...) { // left empty <-- Good Practise??? }

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  • How to replace empty string with zero in comma-separated string?

    - by dsaccount1
    "8,5,,1,4,7,,,,7,,1,9,3,6,,,8,6,3,9,,2,5,4,,,,,3,2,,,7,4,1,1,,4,,6,9,,5,,,,5,,,1,,6,3,,,6,5,,,,7,4,,1,7,6,,,,8,,5,,,7,1,,3,9," I'm doing a programming challenge where i need to parse this sequence into my sudoku script. Need to get the above sequence into 8,5,0,1,4,7,0,0,0,7,0,1,9,3,6,0,0,8......... I tried re but without success, help is appreciated, thanks.

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  • should we use a captcha for Sign Up ?

    - by fabrice
    Hello, I know it's not really a programming question but I don't know where to ask it. Should i use a captcha in my sign up form ? Facebook, twitter, foursquare, gowalla etc... don't use one (or not a visible one). Is there an invisible catpcha on theses sites ? Thank you

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  • work benefits package [closed]

    - by Francisco Garcia
    For those of you who are into programming not just for the money. I would like to know which benefits you would like to have (or already have). OK, maybe taking away the money factor will limit this question too much. I am surprised to see that most companies have a fixed set for their benefits package. Were you able to negotiate something new or just your salary? What things have you seen out there and/or value most?

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  • Show a DB as a directory (Like Sharepoint Does)

    - by Zyd
    Hi, My team and I are programming a sort of Document Manager and the idea is to store them completely on DB. Is there a protocol or Extensions that allows us to show a "Virtual Directory" or files that are really non existent (only in DB). How does Sharepoint do this? I understand that Sharepoint uses WebDav but it implies that the files do exist physically somewhere. We intend to develop this application on .NET 4.0 and deploy it on IIS. Any suggestions? Thanks in advance

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  • Failing to load rootfs: Ubuntu 10 + grub2 + rootfs ext4 w/ RAID1

    - by James
    I am having problems booting a new Ubuntu 10 (server) install. My primary HD (/dev/sda) is laid out as follows: Device Boot Start End Blocks Id System /dev/sda1 * 1 18 144553+ 83 Linux <-- /BOOT /dev/sda2 19 182401 1464991447+ 5 Extended /dev/sda5 19 2207 17583111 fd Linux raid autodetect /dev/sda6 2208 11934 78132096 fd Linux raid autodetect <-- / (ROOTFS) /dev/sda7 11935 182401 1369276146 fd Linux raid autodetect The rootfs is part of a RAID1 (software) array (currently degraded): # cat /proc/mdstat Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] md2 : active raid1 sda6[1] 78132032 blocks [2/1] [_U] The UUIDs for the partitions are as follows: # blkid /dev/sda1 /dev/sda1: UUID="b25dd301-41b9-4f4d-9b0a-0e31713dd74c" TYPE="ext2" # blkid /dev/sda6 /dev/sda6: UUID="af7b9ede-fa53-c0c1-74be-31ec752c5cd5" TYPE="linux_raid_member" # blkid /dev/md2 /dev/md2: UUID="a0602d42-6855-482f-870c-6f6ecdcdae3f" TYPE="ext4" Finally, I have my grub2 menuentry setup as follows: ### BEGIN /etc/grub.d/10_linux ### menuentry 'Ubuntu, with Linux 2.6.32-25-server' --class ubuntu --class gnu-linux --class gnu --class os { insmod ext2 insmod raid insmod mdraid set root='(hd0,1)' search --no-floppy --fs-uuid --set b25dd301-41b9-4f4d-9b0a-0e31713dd74c linux /vmlinuz-2.6.32-25-server root=UUID=a0602d42-6855-482f-870c-6f6ecdcdae3f ro nosplash noplymouth initrd /initrd.img-2.6.32-25-server } When I attempt to boot, grub loads OK, however I eventually get the following error message: Gave up waiting for root device. ALERT /dev/disk/by-uuid/a0602d42-6855-482f-870c-6f6ecdcdae3f does not exist. Dropping to a shell! If from the grub bootloader I open a grub command line, I can ls (hd0,) and it lists the correct partitions with the UUIDs as shown above - sda6 shows 'a0602d42-6855-482f-870c-6f6ecdcdae3f' (the RAID UUID). If I ls (md2)/ it properly lists all the files on the RAID1 filesystem (ext4) so it doesn't appear to be an issue accessing the raid device. Does anyone have any suggestions as to what the problem might be? I can't figure this one out.

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  • how to build good python web application

    - by Moayyad Yaghi
    hello i never worked with web programming and i've been asked lately to write a web-based software to manage assets and tasks. to be used by more than 900 persons what are the recommended modules , frameworks , libraries for this task. and it will be highly appreciated if you guyz recommend some books and articles that might help me. thanks in advance

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  • PHP click event handlers.

    - by Guru
    Hello, I'm new to PHP programming and I wanted to know that is it possible to handle PHP events as we do in ASP.NET I mean I've got a img and I want to perform some task on click event of this img. I know how to do it in ASP.NET but please help me in context of PHP Thanks, GURU

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  • Objects With No Behavior

    - by Patrick Donovan
    I've been teaching myself object oriented programming and I'm thinking about a situation where I have an object "Transaction", that has quite a few properties to it like account, amount, date, currency, type, etc. I never plan to mutate these data points, and calculation logic will live in other classes. My question is, is it poor Python design to instantiate thousands of objects just to hold data? I find the data far easier to work with embedded in a class rather than trying to cram it into some combination of data structures.

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  • Camera and Image recognition

    - by kjh
    I recently watched a youtube video where a guy got a camera to recognize when a rubik's cube was held up to it, and it captured the 9 square color combination before snapping a picture of the cube and displaying the 3x3 grid on the screen of his computer. What kind of programming is this and where would I start reading to get into this sort of thing? specifically, controlling a camera, and getting it to pick out certain parts of an image and translate that data.

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  • iPhone memory management

    - by Prazi
    I am newbie to iPhone programming. I am not using Interface Builder in my programming. I have some doubt about memory management, @property topics in iPhone. Consider the following code @interface LoadFlag : UIViewController { UIImage *flag; UIImageView *preview; } @property (nonatomic, retain) UIImageView *preview; @property (nonatomic, retain) UIImage *flag; @implementation @synthesize preview; @synthesize flag; - (void)viewDidLoad { flag = [UIImage imageNamed:@"myImage.png"]]; NSLog(@"Preview: %d\n",[preview retainCount]); //Count: 0 but shouldn't it be 1 as I am retaining it in @property in interface file preview=[[UIImageView alloc]init]; NSLog(@"Count: %d\n",[preview retainCount]); //Count: 1 preview.frame=CGRectMake(0.0f, 0.0f, 100.0f, 100.0f); preview.image = flag; [self.view addSubview:preview]; NSLog(@"Count: %d\n",[preview retainCount]); //Count: 2 [preview release]; NSLog(@"Count: %d\n",[preview retainCount]); //Count: 1 } When & Why(what is the need) do I have to set @property with retain (in above case for UIImage & UIImageView) ? I saw this statement in many sample programs but didn't understood the need of it. When I declare @property (nonatomic, retain) UIImageView *preview; statement the retain Count is 0. Why doesn't it increase by 1 inspite of retaining it in @property. Also when I declare [self.view addSubview:preview]; then retain Count increments by 1 again. In this case does the "Autorelease pool" releases for us later or we have to take care of releasing it. I am not sure but I think that the Autorelease should handle it as we didn't explicitly retained it so why should we worry of releasing it. Now, after the [preview release]; statement my count is 1. Now I don't need UIImageView anymore in my program so when and where should I release it so that the count becomes 0 and the memory gets deallocated. Again, I am not sure but I think that the Autorelease should handle it as we didn't explicitly retained it so why should we worry of releasing it. What will happen if I release it in -(void) dealloc method In the statement - flag = [UIImage imageNamed:@"myImage.png"]]; I haven't allocated any memory to flag but how can I still use it in my program. In this case if I do not allocate memory then who allocates & deallocates memory to it or is the "flag" just a reference pointing to - [UIImage imageNamed:@"myImage.png"]];. If it is a reference only then do i need to release it. Thanks in advance.

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  • How does UITableViewController knows its dataSource and delegate

    - by denniss
    I am following the BigNerdRanch iOS Programming book and I am on this one chapter that deals with UITableViewController. I have been wondering however where UITableViewController finds out about its delegate and dataSource. Currently I have it as @interface ItemsViewController : UITableViewController <UITableViewDataSource, UITableViewDelegate> But there is nothing that looks like: [self.tableView setDelegate:self] I am just wondering how the UITableViewController finds out about its delegate and dataSource

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