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  • [mysql] diff between tables

    - by www.yegorov-p.ru
    I have two tables, with the same structure, for example: table "first' with columns 'a','b','c' and table 'second' with the same columns. How to find difference betweet those two tables? Of course, I can make some script on python, that will make set(a)-set(b), but I think there is some way to do it in mysql.

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  • How to transform a vector<int> into a string?

    - by Legend
    I am trying to pass a value from C++ to TCL. As I cannot pass pointers without the use of some complicated modules, I was thinking of converting a vector to a char array and then passing this as a null terminated string (which is relatively easy). I have a vector as follows: 12, 32, 42, 84 which I want to convert into something like: "12 32 42 48" The approach I am thinking of is to use an iterator to iterate through the vector and then convert each integer into its string representation and then add it into a char array (which is dynamically created initially by passing the size of the vector). Is this the right way or is there a function that already does this?

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  • How to parse XML file to get specific data effectively

    - by Carlos_Liu
    I have an XML file looks like this: <?xml version="1.0" encoding="utf-8" ?> <PathMasks> <Mask desc="Masks_X1"> <config id="01" mask="88" /> <config id="03" mask="80" /> <config id="51" mask="85" /> </Mask> <Mask desc="Masks_X2"> <config id="70" mask="1" /> <config id="73" mask="6" /> </Mask> <Types> <path id="01" desc="TC->PP1" /> <path id="02" desc="TC->PP2" /> <path id="03" desc="TC->PPn" /> </Types> </PathMasks> How to parse the file and get all the data of Mask_X1 as following: id value ===== 01, 88 03, 80 51, 85

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  • whats the diference between train, validation and test set, in neural networks?

    - by Daniel
    Im using this library http://pastebin.com/raw.php?i=aMtVv4RZ to implement a learning agent. I have generated the train cases, but i dont know for sure what are the validation and test sets, the teacher says: 70% should be train cases, 10% will be test cases and the rest 20% should be validation cases. Thanks. edit i have this code, for training.. but i have no ideia when to stop training.. def train(self, train, validation, N=0.3, M=0.1): # N: learning rate # M: momentum factor accuracy = list() while(True): error = 0.0 for p in train: input, target = p self.update(input) error = error + self.backPropagate(target, N, M) print "validation" total = 0 for p in validation: input, target = p output = self.update(input) total += sum([abs(target - output) for target, output in zip(target, output)]) #calculates sum of absolute diference between target and output accuracy.append(total) print min(accuracy) print sum(accuracy[-5:])/5 #if i % 100 == 0: print 'error %-14f' % error if ? < ?: break

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  • What are the common programming mistakes in Python?

    - by Paul McGuire
    I was about to tag the recent question in which the OP accidentally shadowed the builtin operator module with his own local operator.py with the "common-mistakes" tag, and I saw that there are a number of interesting questions posted asking for common mistakes to avoid in Java, Ruby, Scala, Clojure, .Net, jQuery, Haskell, SQL, ColdFusion, and so on, but I didn't see any for Python. For the benefit of Python beginners, can we enumerate the common mistakes that we have all committed at one time or another, in the hopes of maybe steering a newbie or two clear of them? (In homage to "The Princess Bride", I call these the Classic Blunders.) If possible, a little supporting explanation on what the problem is, and the generally accepted resolution/workaround, so that the beginning Pythoner doesn't read your answer and say "ok, that's a mistake, how do I fix it?"

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  • How do you setLayoutParams() for an ImageView?

    - by DeadTime
    I want to set the LayoutParams for an ImageView but cant seem to find out the proper way to do it. I can only find documentation in the API for the various ViewGroups, but not an ImageView. Yet the ImageView seems to have this functionality. This code doesn't work... myImageView.setLayoutParams(new ImageView.LayoutParams(30,30)); How do I do it?

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  • php array filter

    - by benmsia
    Hi i would like to filter array in php. for example $a = ARRAY('a', 'b', 'c', 'd', 'e'); $b = ARRAY('c', 'd'); $a will be filtered by values in array $b and result is ['a', 'b', 'e'] may I know how to do it in php? Thank you.

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  • So do programming languages get updated regularly like everyday applications or are they just x.0 re

    - by Randy
    I was wondering if programming languages and frameworks get updated in small increments or are they just x.0 releases? And if they do how do you keep up on all the changes in every update? I am specifically interested in Objective-C and Cocoa and CocoaTouch. I'm learning from books and online PDF's etc, but often they are at best a few years old. I just would like to know if there have been any changes etc. that should concern me and even if not, inevitably there will be, so where can I look out for them?

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  • Trying to set up nested while loops using a boolean switch

    - by thorn100
    First time posting. I'm trying to set up a while loop that will ask the user for the employee name, hours worked and hourly wage until the user enters 'DONE'. Eventually I'll modify the code to calculate the weekly pay and write it to a list, but one thing at a time. The problem is once the main while loop executes once, it just stops. Doesn't error out but just stops. I have to kill the program to get it to stop. I want it to ask the three questions again and again until the user is finished. Thoughts? Please note that this is just an exercise and not meant for any real world application. def getName(): """Asks for the employee's full name""" firstName=raw_input("\nWhat is your first name? ") lastName=raw_input("\nWhat is your last name? ") fullName=firstName.title() + " " + lastName.title() return fullName def getHours(): """Asks for the number of hours the employee worked""" hoursWorked=0 while int(hoursWorked)<1 or int(hoursWorked) > 60: hoursWorked=raw_input("\nHow many hours did the employee work: ") if int(hoursWorked)<1 or int(hoursWorked) > 60: print "Please enter an integer between 1 and 60." else: return hoursWorked def getWage(): """Asks for the employee's hourly wage""" wage=0 while float(wage)<6.00 or float(wage)>20.00: wage=raw_input("\nWhat is the employee's hourly wage: ") if float(wage)<6.00 or float(wage)>20.00: print ("Please enter an hourly wage between $6.00 and $20.00") else: return wage ##sentry variables employeeName="" employeeHours=0 employeeWage=0 booleanDone=False #Enter employee info print "Please enter payroll information for an employee or enter 'DONE' to quit." while booleanDone==False: while employeeName=="": employeeName=getName() if employeeName.lower()=="done": booleanDone=True break print "The employee's name is", employeeName while employeeHours==0: employeeHours=getHours() if employeeHours.lower()=="done": booleanDone=True break print employeeName, "worked", employeeHours, "this week." while employeeWage==0: employeeWage=getWage() if employeeWage.lower()=="done": booleanDone=True break print employeeName + "'s hourly wage is $" + employeeWage

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  • error C2440: '=' : cannot convert from 'std::string []' to 'std::string []'

    - by Bach
    now what is wrong with this code! Header: #pragma once #include <string> using namespace std; class Menu { public: Menu(string []); ~Menu(void); }; Implementation: #include "Menu.h" string _choices[]; Menu::Menu(string items[]) { _choices = items; } Menu::~Menu(void) { } compiler is complaining: error C2440: '=' : cannot convert from 'std::string []' to 'std::string []' There are no conversions to array types, although there are conversions to references or pointers to arrays there is no conversion! so what is it on about? please help, just need to pass a bloody array of strings and set it to Menu class _choices[] attribute. thanks

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  • GoTo statements, and alternatives (help me please im new) (VB.net)

    - by qais
    Basically I posted a code snippet on a forum asking for help and people pointed out to me that using GoTo statements is very bad programming practise so I'm just wondering, why is it bad? And also what alternative is there to use, like for example in this program ive done for homework the user has to input their date of birth and if the month/date/year are invalid or unrealistic(using if statements checking the integer inputs size, if theres any better way to do this i'd appreciate if you could tell me that also :D) then how would i be able to loop back to ask them again? heres a little extract of my code retryday: Console.WriteLine("Please enter the day you were born : ") day = Console.ReadLine If day > 31 Or day < 1 Then Console.WriteLine("Please enter a valid day") GoTo retryday End If

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  • Codeigniter: Checklist for new users & logistics of app

    - by Kevin Brown
    I'm developing my first web-app, and I'm working through logistics. New users (At first login) need to complete a few things before they can use the app fully. For example, they need to complete their profile before they can move on to step 2, which is taking a test. What's the best way to go about creating a "new-user" checklist? I want it to be as simple as possible, coding wise, and as easy as possible for the user.

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  • The confusion on python encoding

    - by zhangzhong
    I retrieved the data encoded in big5 from database,and I want to send the data as email of html content, the code is like this: html += """<tr><td>""" html += """unicode(rs[0], 'big5')""" # rs[0] is data encoded in big5 I run the script, but the error raised: UnicodeDecodeError: 'ascii' codec can't decode byte...... However, I tried the code in interactive python command line, there are no errors raised, could you give me the clue?

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  • View Animation (Resizing a Ball)

    - by user270811
    hi, i am trying to do this: 1) user long touches the screen, 2) a circle/ball pops up (centered around the user's finger) and grows in size as long as the user is touching the screen 3) once the user lets go of the finger, the ball (now in its final size) will bounce around. i think i have the bouncing around figure out from the DivideAndConquer example, but i am not sure how to animate the ball's growth. i looked at various view flipper examples such as this: http://www.inter-fuser.com/2009/08/android-animations-3d-flip.html but it seems like view flipper is best for swapping two static pictures. i wasn't able to find a good view animator example other than the flippers. also, i would prefer to use images as opposed to just a circle. can someone point me in the right direction? thanks.

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  • Problem compiling c++ in CodeGear

    - by Carlos
    I have written a C++ program for a University assignment. I used Netbeans 6.8 running on my Mac and the code runs smoothly, no warnings, errors or problems/bugs. However when compiling and running on a Windows computer using CodeGear RAD Studio 2009 (C++ Builder) am getting several errors. [BCC32 Error] main.cpp(51): E2094 'operator<<' not implemented in type 'ostream' for arguments of type 'string' [BCC32 Error] main.cpp(62): E2093 'operator==' not implemented in type 'string' for arguments of the same type [BCC32 Error] main.cpp(67): E2093 'operator==' not implemented in type 'string' for arguments of the same type [BCC32 Error] main.cpp(112): E2093 'operator==' not implemented in type 'string' for arguments of the same type [BCC32 Error] main.cpp(121): E2094 'operator<<' not implemented in type 'ostream' for arguments of type 'string' [BCC32 Error] main.cpp(130): E2093 'operator==' not implemented in type 'string' for arguments of the same type [BCC32 Error] main.cpp(133): E2094 'operator<<' not implemented in type 'ostream' for arguments of type 'string' [BCC32 Error] main.cpp(139): E2094 'operator<<' not implemented in type 'ostream' for arguments of type 'string' [BCC32 Error] main.cpp(153): E2094 'operator<<' not implemented in type 'fstream' for arguments of type 'string' [BCC32 Error] main.cpp(199): E2094 'operator>>' not implemented in type 'fstream' for arguments of type 'string' [BCC32 Error] main.cpp(219): E2094 'operator>>' not implemented in type 'istream' for arguments of type 'string' [BCC32 Error] main.cpp(231): E2094 'operator>>' not implemented in type 'istream' for arguments of type 'string' [BCC32 Error] main.cpp(240): E2094 'operator>>' not implemented in type 'istream' for arguments of type 'string' [BCC32 Error] main.cpp(262): E2094 'operator>>' not implemented in type 'istream' for arguments of type 'string' [BCC32 Error] main.cpp(264): E2094 'operator>>' not implemented in type 'istream' for arguments of type 'string' These are the header files am using #include <iostream> #include <fstream> #include <cmath> #include <stdio> #include <windows> //I added this one just to check and still does not work (I didnt have it on Netbeans/Mac) using namespace std; Any ideas what is producing the errors and how can I fix it?

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  • Do I correctly understand what a class is?

    - by Matt
    I've had trouble finding a clear, concise laymans definition of a class. Usually, they give general ideas without specifically spelling it out, and I'm wondering if I'm understanding this correctly. As I understand it, a class is the set of code that controls an object. For example, in an app that has a button for 'Yes' and a button for 'No', and a text box for output, the code that tells the computer what to do when the user uses the Yes button is one class, the code for hitting No is another class, and an object is the two buttons and what they do together to influence the output box. Am I right, or am I confusing terms here? Thanks

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  • python regex of a date in some text, enclosed by two keywords

    - by Horace Ho
    This is Part 2 of this question and thanks very much for David's answer. What if I need to extract dates which are bounded by two keywords? Example: text = "One 09 Jun 2011 Two 10 Dec 2012 Three 15 Jan 2015 End" Case 1 bounding keyboards: "One" and "Three" Result expected: ['09 Jun 2011', '10 Dec 2012'] Case 2 bounding keyboards: "Two" and "End" Result expected: ['10 Dec 2012', '15 Jan 2015'] Thanks!

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  • Am I doing getters/setters the right way in Java?

    - by Sergio Tapia
    public class Persona { int Codigo; String Nombre; public Persona(int Codigo, String Nombre){ this.Codigo = Codigo; this.Nombre = Nombre; } public void setCodigo(int Codigo){ this.Codigo = Codigo; } public int getCodigo(){ return this.Codigo; } public void setNombre(String Nombre){ this.Nombre = Nombre; } public String getNombre(){ return this.Nombre; } } Or is there a much shorter (realiable) way to do it?

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  • How does PHP work - literature

    - by Ondrej Slinták
    I'm interested in literature (articles on internet, in magazines, books, podcasts - I don't really mind anything) that describes how PHP works internally, about its gotchas and perhaps some advanced functions. Is there anything like this out there? I tried to search on Google, but majority of articles were about starting with PHP and its basic functions. Any input is really welcome as I'm trying to understand the language internally - I'm tired of my mindless typing of code without understanding its essence.

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