Search Results

Search found 16393 results on 656 pages for 'long gu'.

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

Page 62/656 | < Previous Page | 58 59 60 61 62 63 64 65 66 67 68 69  | Next Page >

  • Using functions like formulas in Excel

    - by Arlen Beiler
    I am trying to use a formula to get a letter of the alphabet. Formula: =Keytable(RANDOM,ROW()) Function: Function KeyTable(seed As Long, position As Long) As String Dim i As Long Stop Dim calpha(1 To 26) As String Dim alpha(1 To 26) As String For i = 1 To 26 alpha(i) = Chr(i + UPPER_CASE - 1) Next i For i = 1 To 26 calpha(i) = alpha(seed Mod 27 - i) Next i Stop KeyTable = calpha(position) End Function Result: #Value! When I step through the function, it never gets to the second stop.

    Read the article

  • template function roundTo int, float -> truncation

    - by Oops
    Hi, according to this question: http://stackoverflow.com/questions/2833730/calling-template-function-without-type-inference the round function I will use in the future now looks like: template < typename TOut, typename TIn > TOut roundTo( TIn value ) { return static_cast<TOut>( value + 0.5 ); } double d = 1.54; int i = rountTo<int>(d); However it makes sense only if it will be used to round to integral datatypes like char, short, int, long, long long int, and it's unsigned counterparts. If it ever will be used with a TOut As float or long double it will deliver s***. double d = 1.54; float f = roundTo<float>(d); // aarrrgh now float is 2.04; I was thinking of a specified overload of the function but ... that's not possible... How would you solve this problem? many thanks in advance Oops

    Read the article

  • c++ to vb.net , problem with callback function

    - by johan
    I'm having a hard time here trying to find a solution for my problem. I'm trying to convert a client API funktion from C++ to VB.NET, and i think have some problems with the callback function. parts of the C++ code: typedef struct{ BYTE m_bRemoteChannel; BYTE m_bSendMode; BYTE m_nImgFormat; // =0 cif ; = 1 qcif char *m_sIPAddress; char *m_sUserName; char *m_sUserPassword; BOOL m_bUserCheck; HWND m_hShowVideo; }CLIENT_VIDEOINFO, *PCLIENT_VIDEOINFO; CPLAYER_API LONG __stdcall MP4_ClientStart(PCLIENT_VIDEOINFO pClientinfo,void(CALLBACK *ReadDataCallBack)(DWORD nPort,UCHAR *pPacketBuffer,DWORD nPacketSize)); void CALLBACK ReadDataCallBack(DWORD nPort,UCHAR *pPacketBuffer,DWORD nPacketSize) { TRACE("%d\n",nPacketSize); } ..... aa5.m_sUserName = "123"; aa5.m_sUserPassword="w"; aa5.m_bUserCheck = TRUE; MP4_ClientSetTTL(64); nn1 = MP4_ClientStart(&aa5,ReadDataCallBack); if (nn1 == -1) { MessageBox("error"); return; } SDK description: MP4_ClientStart This function starts a connection. The format of the call is: LONG __stdcall MP4_ClientStart(PCLIENT_VIDEOINFO pClientinfo, void(*ReadDataCallBack)(DWORD nChannel,UCHAR *pPacketBuffer,DWORD nPacketSize)) Parameters pClientinfo holds the information. of this connection. nChannel holds the channel of card. pPacketBuffer holds the pointer to the receive buffer. nPacketSize holds the length of the receive buffer. Return Values If the function succeeds the return value is the context of this connection. If the function fails the return value is -1. Remarks typedef struct{ BYTE m_bRemoteChannel; BYTE m_bSendMode; BYTE m_bImgFormat; char *m_sIPAddress; char *m_sUserName; char *m_sUserPassword; BOOL m_bUserCheck; HWND m_hShowVideo; } CLIENT_VIDEOINFO, * PCLIENT_VIDEOINFO; m_bRemoteChannel holds the channel which the client wants to connect to. m_bSendMode holds the network mode of the connection. m_bImgFormat : Image format, 0 is main channel video, 1 is sub channel video m_sIPAddress holds the IP address of the server. m_sUserName holds the user’s name. m_sUserPassword holds the user’s password. m_bUserCheck holds the value whether sends the user’s name and password or not. m_hShowVideo holds Handle for this video window. If m_hShowVideo holds NULL, the client can be record only without decoder. If m_bUserCheck is FALSE, we will send m_sUserName and m_sUserPassword as NULL, else we will send each 50 bytes. The length of m_sIPAddress and m_sUserName must be more than 50 bytes. ReadDataCallBack: When the library receives a packet from a server, this callback is called. My VB.Net code: Imports System.Runtime.InteropServices Public Class Form1 Const WM_USER = &H400 Public Structure CLIENT_VIDEOINFO Public m_bRemoteChannel As Byte Public m_bSendMode As Byte Public m_bImgFormat As Byte Public m_sIPAddress As String Public m_sUserName As String Public m_sUserPassword As String Public m_bUserCheck As Boolean Public m_hShowVideo As Long 'hWnd End Structure Public Declare Function MP4_ClientSetNetPort Lib "hikclient.dll" (ByVal dServerPort As Integer, ByVal dClientPort As Integer) As Boolean Public Declare Function MP4_ClientStartup Lib "hikclient.dll" (ByVal nMessage As UInteger, ByVal hWnd As System.IntPtr) As Boolean <DllImport("hikclient.dll")> Public Shared Function MP4_ClientStart(ByVal Clientinfo As CLIENT_VIDEOINFO, ByRef ReadDataCallBack As CALLBACKdel) As Long End Function Public Delegate Sub CALLBACKdel(ByVal nPort As Long, <MarshalAs(UnmanagedType.LPArray)> ByRef pPacketBuffer As Byte(), ByVal nPacketSize As Long) Public Sub CALLBACK(ByVal nPort As Long, <MarshalAs(UnmanagedType.LPArray)> ByRef pPacketBuffer As Byte(), ByVal nPacketSize As Long) End Sub Public mydel As New CALLBACKdel(AddressOf CALLBACK) Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load Dim Clientinfo As New CLIENT_VIDEOINFO() Clientinfo.m_bRemoteChannel = 0 Clientinfo.m_bSendMode = 0 Clientinfo.m_bImgFormat = 0 Clientinfo.m_sIPAddress = "193.168.1.100" Clientinfo.m_sUserName = "1" Clientinfo.m_sUserPassword = "a" Clientinfo.m_bUserCheck = False Clientinfo.m_hShowVideo = Me.Handle 'Nothing MP4_ClientSetNetPort(850, 850) MP4_ClientStartup(WM_USER + 1, Me.Handle) MP4_ClientStart(Clientinfo, mydel) End Sub End Class here is some other examples of the code in: C# http://blog.csdn.net/nenith1981/archive/2007/09/17/1787692.aspx VB ://read.pudn.com/downloads70/sourcecode/graph/250633/MD%E5%AE%A2%E6%88%B7%E7%AB%AF%28VB%29/hikclient.bas__.htm ://read.pudn.com/downloads70/sourcecode/graph/250633/MD%E5%AE%A2%E6%88%B7%E7%AB%AF%28VB%29/Form1.frm__.htm Delphi ://read.pudn.com/downloads91/sourcecode/multimedia/streaming/349759/Delphi_client/Unit1.pas__.htm

    Read the article

  • Is there a way to dynamically define the height and width that are going to appear in a page?

    - by Starx
    For so many time, I have encountered problems with managing image having abnormally long height or width. If I fixed their height and widht, they will appear streched? If I fixed their width, and if the height of the image is very long then also it will mess up the overall website. If I fixed their height, and if the width of the image is very long then also it will mess up the overall website. How is the best way to fix this?

    Read the article

  • How can I figure out a users postal code if I have their latitude / longitude location? Need help w

    - by mike
    I'm using HTML5 geolocation to collect the users lat / long and I need to figure out what their postal code is as well. I have a database of all the lat / long for each postal code in the US & Canada. How can I write a query to find out what their postal code is? Below, is an example of how the data is structured in the 'zips' table. Country PostalCode Latitude Longitude USA 0051 40.813078 -73.046388 USA 00616 18.426456 -66.673779 I can't do a 'SELECT PostalCode FROM zips WHERE Latitude = user.lat AND Longitude = user.long'. I believe I need to find the nearest lat / long. Any suggestions on how I can write this?

    Read the article

  • Formatting Field Declarations in Eclipse

    - by geeko
    Greetings Overflowers, Problem: public abstract class Filter { private long id; protected String expression; } how can I align fields automatically in Eclipse, such in: public abstract class Filter { private long id; protected String expression; } Note the space before long, thank you ! UPDATE: I cannot find a customization option to align types of class members (e.g.: long and String) under Eclipse formatter options. Yes, there is one to align names of class members (e.g.: id and expression) but not their types. Please, take a lock at this issue in my examples above. Any solution ?

    Read the article

  • Constructing a function call in C

    - by 0x6adb015
    Given that I have a pointer to a function (provided by dlsym() for example) and a linked list of typed arguments, how can I construct a C function call with those arguments? Example: struct param { enum type { INT32, INT64, STRING, BOOL } type; union { int i32; long long i64; char *str; bool b; } value; struct param *next; }; int call_this(int (*function)(), struct param *args) { int result; /* magic here that calls function(), which has a prototype of f(int, long long, char *, bool); , when args consist of a linked list of INT32, INT64, STRING, BOOL types. */ return result; } The OS is Linux. I would like the solution to be portable across MIPS, PPC and x86 (all 32 bits) architecture, using GCC as the compiler. Thanks!

    Read the article

  • Bash PWD Shortening

    - by dlibby00
    I'm looking for a bash function that will shorten long path names to keep my PS1 variable from getting excessively long. Something along the lines of: /this/is/the/path/to/a/really/long/directory/i/would/like/shortened might end up as: /t../i../t../p../to/a/r../l../d../i/w../like/shortened something that the took the path and a maximum acceptable number of characters to shorten to would be perfect for my .bashrc file.

    Read the article

  • Using pow() for large number

    - by g4ur4v
    I am trying to solve a problem, a part of which requires me to calculate (2^n)%1000000007 , where n<=10^9. But my following code gives me output "0" even for input like n=99. Is there anyway other than having a loop which multilplies the output by 2 every time and finding the modulo every time (this is not I am looking for as this will be very slow for large numbers). #include<stdio.h> #include<math.h> #include<iostream> using namespace std; int main() { unsigned long long gaps,total; while(1) { cin>>gaps; total=(unsigned long long)powf(2,gaps)%1000000007; cout<<total<<endl; } }

    Read the article

  • Can i use a generic implicit or explicit operator? C#

    - by acidzombie24
    How do i change the following statement so it accepts any type instead of long? Now here is the catch, if there is no constructor i dont want it compiling. So if theres a constructor for string, long and double but no bool how do i have this one line work for all of these support types? ATM i just copied pasted it but i wouldnt like doing that if i had 20types (as trivial as the task may be) public static explicit operator MyClass(long v) { return new MyClass(v); }

    Read the article

  • C -- Basic Struct questions

    - by Ryan Yu
    So I'm trying to learn C right now, and I have some basic struct questions I'd like to clear up: Basically, everything centers around this snippet of code: #include <stdio.h> #include <stdlib.h> #define MAX_NAME_LEN 127 typedef struct { char name[MAX_NAME_LEN + 1]; unsigned long sid; } Student; /* return the name of student s */ const char* getName (const Student* s) { // the parameter 's' is a pointer to a Student struct return s->name; // returns the 'name' member of a Student struct } /* set the name of student s If name is too long, cut off characters after the maximum number of characters allowed. */ void setName(Student* s, const char* name) { // 's' is a pointer to a Student struct | 'name' is a pointer to the first element of a char array (repres. a string) s->name = name; } /* return the SID of student s */ unsigned long getStudentID(const Student* s) { // 's' is a pointer to a Student struct return s->sid; } /* set the SID of student s */ void setStudentID(Student* s, unsigned long sid) { // 's' is a pointer to a Student struct | 'sid' is a 'long' representing the desired SID s->sid = sid; } I've commented up the code in an attempt to solidify my understanding of pointers; I hope they're all accurate. So anyway, I have a feeling that setName and setStudentID aren't correct, but I'm not exactly sure why. Can someone explain? Thanks!

    Read the article

  • JPA hibernate OneToOne mapping

    - by Stupidfrog
    enviroment: hibernate 4.1.6.final spring 3.1.2.release spring jpa 1.1.0.release postgresql 9.1-901-1.jdbc4 there is 2 table public A { private Long id; private Long name; } public B { private Long id; private Long table_a_id; } the A.id and B.id is sequential, unique , but no related.(means they are separately id for their own table). how to do mapping? i have tried some method, however the result is not i wanted, because it bind wrong. for example: public A { .... @OneToOne @JoinColumn(name = "id") private B table_b } public B { ... @JsonIgnore @OneToOne(mappedBy = "table_b") private A table_a; } when i query A the result is { "id":5, "table_b":{ "id":5, "table_a_id":4 } } obviously the data join by using their id but not joining using table_a_id. what i expect is { "id":4, "table_b":{ "id":5, "table_a_id":4 } } so can somebody teach me that, how to map this 2 table by using table b table_a_id(foregin key)

    Read the article

  • C Typecast: How to

    - by Jean
    #include<stdio.h> int main(void) { unsigned short a,e,f ; // 2 bytes data type unsigned int temp1,temp2,temp4; // 4 bytes data type unsigned long temp3; // 8 bytes data type a=0xFFFF; e=((a*a)+(a*a))/(2*a); // Line 8 //e=(((unsigned long)(a*a)+(unsigned long)(a*a)))/(unsigned int)(2*a); temp1=a*a; temp2=a*a; temp3=(unsigned long)temp1+(unsigned long)temp2; // Line 14 temp4=2*a; f=temp3/temp4; printf("%u,%u,%lu,%u,%u,%u,%u\n",temp1,temp2,temp3,temp4,e,f,a); return(1); } How do I fix the arithmetic (At Line 8 by appropriate typecasting of intermediate results) so that overflows are taken care of ? Currently it prints 65534 instead of expected 65535. Why is the typecast necessary for Line 14 ?

    Read the article

  • Can anyone tell me were I am making mistake in the snippet

    - by Solitaire
    public partial class Form1 : Form { [DllImport("coredll.dll")] static extern int SetWindowLong(IntPtr hWnd, int nIndex, int dwNewLong); const int GWL_WNDPROC = -4; public delegate int WindProc(IntPtr hWnd, uint msg, long Wparam, long lparam); public Form1() { InitializeComponent(); WindProc SampleProc = new WindProc (SubclassWndProc); SetWindowLong(this .Handle , GWL_WNDPROC, SampleProc.Method .MethodHandle.Value.ToInt32()); } public int SubclassWndProc(IntPtr hwnd, uint msg, long Wparam, long lparam) { return 1; } Here is the sample which i was trying to take the window procedure of a form, this is how i do in C++ i get the windwproc easlily if i try the same in C# .net 3.5 i am unable to get the window proc,, after calling SetWindowLong API application hangs and it pops up some dont send report... i have read this is the way to get the window proc.. please let me know were i am making mistake...

    Read the article

  • GCC doesn't like C++ style casts with spaces

    - by uj2
    I am porting some C++ code to GCC, and apperantly it isn't happy with C++ style casting when sapces are involved, as in unsigned int(-1), long long(ShortVar) etc... It gives an error: expected primary-expression before 'long'. Is there any way to make peace with GCC without going over each one of those and rewrite in c-style?

    Read the article

  • boost scoped_lock mutex crashes

    - by JahSumbar
    hello, I have protected a std::queue's access functions, push, pop, size, with boost::mutexes and boost::mutex::scoped_lock in these functions from time to time it crashes in a scoped lock the call stack is this: 0 0x0040f005 boost::detail::win32::interlocked_bit_test_and_set include/boost/thread/win32/thread_primitives.hpp 361 1 0x0040e879 boost::detail::basic_timed_mutex::timed_lock include/boost/thread/win32/basic_timed_mutex.hpp 68 2 0x0040e9d3 boost::detail::basic_timed_mutex::lock include/boost/thread/win32/basic_timed_mutex.hpp 64 3 0x0040b96b boost::unique_lock<boost::mutex>::lock include/boost/thread/locks.hpp 349 4 0x0040b998 unique_lock include/boost/thread/locks.hpp 227 5 0x00403837 MyClass::inboxSize - this is my inboxSize function that uses this code: MyClass::inboxSize () { boost::mutex::scoped_lock scoped_lock(m_inboxMutex); return m_inbox.size(); } and the mutex is declared like this: boost::mutex m_inboxMutex; it crashes at the last pasted line in this function: inline bool interlocked_bit_test_and_set(long* x,long bit) { long const value=1<<bit; long old=*x; and x has this value: 0xababac17 Thanks for the help

    Read the article

  • Make conversion to a native type explicit in C++

    - by Tal Pressman
    I'm trying to write a class that implements 64-bit ints for a compiler that doesn't support long long, to be used in existing code. Basically, I should be able to have a typedef somewhere that selects whether I want to use long long or my class, and everything else should compile and work. So, I obviously need conversion constructors from int, long, etc., and the respective conversion operators (casts) to those types. This seems to cause errors with arithmetic operators. With native types, the compiler "knows" that when operator*(int, char) is called, it should promote the char to int and call operator*(int, int) (rather than casting the int to char, for example). In my case it gets confused between the various built-in operators and the ones I created. It seems to me like if I could flag the conversion operators as explicit somehow, that it would solve the issue, but as far as I can tell the explicit keyword is only for constructors (and I can't make constructors for built-in types). So is there any way of marking the casts as explicit? Or am I barking up the wrong tree here and there's another way of solving this? Or maybe I'm just doing something else wrong...

    Read the article

  • Chat app vs REST app - use a thread in an Activity or a thread in a Service?

    - by synic
    In Virgil Dobjanschi's talk, "Developing Android REST client applications" (link here), he said a few things that took me by surprise. Including: Don't run http queries in threads spawned by your activities. Instead, communicate with a service to do them, and store the information in a ContentProvider. Use a ContentObserver to be notified of changes. Always perform long running tasks in a Service, never in your Activity. Stop your Service when you're done with it. I understand that he was talking about a REST API, but I'm trying to make it fit with some other ideas I've had for apps. One of APIs I've been using uses long-polling for their chat interface. There is a loop http queries, most of which will time out. This means that, as long as the app hasn't been killed by the OS, or the user hasn't specifically turned off the chat feature, I'll never be done with the Service, and it will stay open forever. This seems less than optimal. Long question short: For a chat application that uses long polling to simulate push and immediate response, is it still best practice to use a Service to perform the HTTP queries, and store the information in a ContentProvider?

    Read the article

  • question about Ackermann function

    - by davit-datuashvili
    i am doing to write recursive program which calculates Ackemann function http://en.wikipedia.org/wiki/Ackermann_function here is code public class Ackermann{ public static long ackermann( long m,long n){ return (m==0)? n+1: (m>0 && n==0)? ackermann(m-1,1): (m>0 && n>0)? ackermann(m-1, ackermann(m,n-1)); } public static void main(String[]args){ long m=4; long n=2; System.out.println(ackermann(m,n)); } } but it shows me mistakes Ackermann.java:7: : expected (m>0 && n>0)? ackermann(m-1, ackermann(m,n-1)); ^ Ackermann.java:7: ';' expected (m>0 && n>0)? ackermann(m-1, ackermann(m,n-1)); ^ Ackermann.java:18: illegal start of expression public static void main(String[]args){ ^ Ackermann.java:18: ';' expected public static void main(String[]args){ ^ Ackermann.java:18: illegal start of expression public static void main(String[]args){ ^ Ackermann.java:18: ';' expected public static void main(String[]args){ ^ Ackermann.java:18: ';' expected public static void main(String[]args){ ^ Ackermann.java:26: reached end of file while parsing } ^ 8 errors please help

    Read the article

  • Define a positive number to be isolated if none of the digits in its square are in its cube [closed]

    - by proglaxmi
    Define a positive number to be isolated if none of the digits in its square are in its cube. For example 163 is n isolated number because 69*69 = 26569 and 69*69*69 = 4330747 and the square does not contain any of the digits 0, 3, 4 and 7 which are the digits used in the cube. On the other hand 162 is not an isolated number because 162*162=26244 and 162*162*162 = 4251528 and the digits 2 and 4 which appear in the square are also in the cube. Write a function named isIsolated that returns 1 if its argument is an isolated number, it returns 0 if its not an isolated number and it returns -1 if it cannot determine whether it is isolated or not (see the note below). The function signature is: int isIsolated(long n) Note that the type of the input parameter is long. The maximum positive number that can be represented as a long is 63 bits long. This allows us to test numbers up to 2,097,151 because the cube of 2,097,151 can be represented as a long. However, the cube of 2,097,152 requires more than 63 bits to represent it and hence cannot be computed without extra effort. Therefore, your function should test if n is larger than 2,097,151 and return -1 if it is. If n is less than 1 your function should also return -1. Hint: n % 10 is the rightmost digit of n, n = n/10 shifts the digits of n one place to the right. The first 10 isolated numbers are N n*n n*n*n 2 4 8 3 9 27 8 64 512 9 81 729 14 196 2744 24 576 13824 28 784 21952 34 1156 39304 58 3364 195112 63 3969 250047

    Read the article

  • jquery XML, i need .html() not .text() but not working?

    - by Xtian
    I need var long to be exported as html and not text. I know I have .text() but when I use .html() it will not work. Also if I take the .text() out when declaring the variable and it will not work in IE? The reason for this is, in the XML certain words will have html tags like or and I need those to be recognized. I thought I solved it when I took out .text() but then i looked at IE and I got nothing. $(document).ready(function(){ $.ajax({ type: "GET", url: "xml/sites.xml", dataType: "xml", success: function(xml) { $(xml).find('site').each(function(){ var id = $(this).attr('id'); var title = $(this).find('title').text(); var class =$(this).find('class').text(); $('<div class="'+class+'" id="link_'+id+'"></div>').html('<h2>'+title+'</h2>').appendTo('#page-wrap'); $(this).find('desc').each(function(){ var long = $(this).find('long'); var url = $(this).find('url').text(); $('<div class="long"></div>').html(long).appendTo('#link_'+id); $('<a href="http://'+url+'"</a>').html(url).appendTo('#link_'+id); }); }); } }); });// JavaScript Document

    Read the article

  • Project Euler #3

    - by Alex
    Question: The prime factors of 13195 are 5, 7, 13 and 29. What is the largest prime factor of the number 600851475143? I found this one pretty easy, but running the file took an extremely long time, it's been going on for a while and the highest number I've got to is 716151937. Here is my code, am I just going to have a wait or is there an error in my code? //User made class public class Three { public static boolean checkPrime(long p) { long i; boolean prime = false; for(i = 2;i<p/2;i++) { if(p%i==0) { prime = true; break; } } return prime; } } //Note: This is a separate file public class ThreeMain { public static void main(String[] args) { long comp = 600851475143L; boolean prime; long i; for(i=2;i<comp/2;i++) { if(comp%i==0) { prime = Three.checkPrime(i); if(prime==true) { System.out.println(i); } } } } }

    Read the article

  • In a JDBC ResultSet, what should happen when getLong() or getShort() is called on an int result colu

    - by Uri
    Say that I have a JDBC ResultSet, and I call the getLong() or getshort() method. For which of the following SQL types {SMALLINT, INT, BIGINT} should I get long, and for which types should I get an error? In other words, if I have an INT and I want a SMALLINT (A short), would I get it, or would I get an error? Similarly, if I have an INT and want a BIGINT (a long), would I get it, or would I get an error? The Javadocs (listed below) say nothing. public long getLong(int columnIndex) throws SQLException Retrieves the value of the designated column in the current row of this ResultSet object as a long in the Java programming language. Parameters: columnIndex - the first column is 1, the second is 2, ... Returns: the column value; if the value is SQL NULL, the value returned is 0 Throws: SQLException - if a database access error occurs

    Read the article

  • The Incremental Architect&acute;s Napkin &ndash; #3 &ndash; Make Evolvability inevitable

    - by Ralf Westphal
    Originally posted on: http://geekswithblogs.net/theArchitectsNapkin/archive/2014/06/04/the-incremental-architectacutes-napkin-ndash-3-ndash-make-evolvability-inevitable.aspxThe easier something to measure the more likely it will be produced. Deviations between what is and what should be can be readily detected. That´s what automated acceptance tests are for. That´s what sprint reviews in Scrum are for. It´s no small wonder our software looks like it looks. It has all the traits whose conformance with requirements can easily be measured. And it´s lacking traits which cannot easily be measured. Evolvability (or Changeability) is such a trait. If an operation is correct, if an operation if fast enough, that can be checked very easily. But whether Evolvability is high or low, that cannot be checked by taking a measure or two. Evolvability might correlate with certain traits, e.g. number of lines of code (LOC) per function or Cyclomatic Complexity or test coverage. But there is no threshold value signalling “evolvability too low”; also Evolvability is hardly tangible for the customer. Nevertheless Evolvability is of great importance - at least in the long run. You can get away without much of it for a short time. Eventually, though, it´s needed like any other requirement. Or even more. Because without Evolvability no other requirement can be implemented. Evolvability is the foundation on which all else is build. Such fundamental importance is in stark contrast with its immeasurability. To compensate this, Evolvability must be put at the very center of software development. It must become the hub around everything else revolves. Since we cannot measure Evolvability, though, we cannot start watching it more. Instead we need to establish practices to keep it high (enough) at all times. Chefs have known that for long. That´s why everybody in a restaurant kitchen is constantly seeing after cleanliness. Hygiene is important as is to have clean tools at standardized locations. Only then the health of the patrons can be guaranteed and production efficiency is constantly high. Still a kitchen´s level of cleanliness is easier to measure than software Evolvability. That´s why important practices like reviews, pair programming, or TDD are not enough, I guess. What we need to keep Evolvability in focus and high is… to continually evolve. Change must not be something to avoid but too embrace. To me that means the whole change cycle from requirement analysis to delivery needs to be gone through more often. Scrum´s sprints of 4, 2 even 1 week are too long. Kanban´s flow of user stories across is too unreliable; it takes as long as it takes. Instead we should fix the cycle time at 2 days max. I call that Spinning. No increment must take longer than from this morning until tomorrow evening to finish. Then it should be acceptance checked by the customer (or his/her representative, e.g. a Product Owner). For me there are several resasons for such a fixed and short cycle time for each increment: Clear expectations Absolute estimates (“This will take X days to complete.”) are near impossible in software development as explained previously. Too much unplanned research and engineering work lurk in every feature. And then pervasive interruptions of work by peers and management. However, the smaller the scope the better our absolute estimates become. That´s because we understand better what really are the requirements and what the solution should look like. But maybe more importantly the shorter the timespan the more we can control how we use our time. So much can happen over the course of a week and longer timespans. But if push comes to shove I can block out all distractions and interruptions for a day or possibly two. That´s why I believe we can give rough absolute estimates on 3 levels: Noon Tonight Tomorrow Think of a meeting with a Product Owner at 8:30 in the morning. If she asks you, how long it will take you to implement a user story or bug fix, you can say, “It´ll be fixed by noon.”, or you can say, “I can manage to implement it until tonight before I leave.”, or you can say, “You´ll get it by tomorrow night at latest.” Yes, I believe all else would be naive. If you´re not confident to get something done by tomorrow night (some 34h from now) you just cannot reliably commit to any timeframe. That means you should not promise anything, you should not even start working on the issue. So when estimating use these four categories: Noon, Tonight, Tomorrow, NoClue - with NoClue meaning the requirement needs to be broken down further so each aspect can be assigned to one of the first three categories. If you like absolute estimates, here you go. But don´t do deep estimates. Don´t estimate dozens of issues; don´t think ahead (“Issue A is a Tonight, then B will be a Tomorrow, after that it´s C as a Noon, finally D is a Tonight - that´s what I´ll do this week.”). Just estimate so Work-in-Progress (WIP) is 1 for everybody - plus a small number of buffer issues. To be blunt: Yes, this makes promises impossible as to what a team will deliver in terms of scope at a certain date in the future. But it will give a Product Owner a clear picture of what to pull for acceptance feedback tonight and tomorrow. Trust through reliability Our trade is lacking trust. Customers don´t trust software companies/departments much. Managers don´t trust developers much. I find that perfectly understandable in the light of what we´re trying to accomplish: delivering software in the face of uncertainty by means of material good production. Customers as well as managers still expect software development to be close to production of houses or cars. But that´s a fundamental misunderstanding. Software development ist development. It´s basically research. As software developers we´re constantly executing experiments to find out what really provides value to users. We don´t know what they need, we just have mediated hypothesises. That´s why we cannot reliably deliver on preposterous demands. So trust is out of the window in no time. If we switch to delivering in short cycles, though, we can regain trust. Because estimates - explicit or implicit - up to 32 hours at most can be satisfied. I´d say: reliability over scope. It´s more important to reliably deliver what was promised then to cover a lot of requirement area. So when in doubt promise less - but deliver without delay. Deliver on scope (Functionality and Quality); but also deliver on Evolvability, i.e. on inner quality according to accepted principles. Always. Trust will be the reward. Less complexity of communication will follow. More goodwill buffer will follow. So don´t wait for some Kanban board to show you, that flow can be improved by scheduling smaller stories. You don´t need to learn that the hard way. Just start with small batch sizes of three different sizes. Fast feedback What has been finished can be checked for acceptance. Why wait for a sprint of several weeks to end? Why let the mental model of the issue and its solution dissipate? If you get final feedback after one or two weeks, you hardly remember what you did and why you did it. Resoning becomes hard. But more importantly youo probably are not in the mood anymore to go back to something you deemed done a long time ago. It´s boring, it´s frustrating to open up that mental box again. Learning is harder the longer it takes from event to feedback. Effort can be wasted between event (finishing an issue) and feedback, because other work might go in the wrong direction based on false premises. Checking finished issues for acceptance is the most important task of a Product Owner. It´s even more important than planning new issues. Because as long as work started is not released (accepted) it´s potential waste. So before starting new work better make sure work already done has value. By putting the emphasis on acceptance rather than planning true pull is established. As long as planning and starting work is more important, it´s a push process. Accept a Noon issue on the same day before leaving. Accept a Tonight issue before leaving today or first thing tomorrow morning. Accept a Tomorrow issue tomorrow night before leaving or early the day after tomorrow. After acceptance the developer(s) can start working on the next issue. Flexibility As if reliability/trust and fast feedback for less waste weren´t enough economic incentive, there is flexibility. After each issue the Product Owner can change course. If on Monday morning feature slices A, B, C, D, E were important and A, B, C were scheduled for acceptance by Monday evening and Tuesday evening, the Product Owner can change her mind at any time. Maybe after A got accepted she asks for continuation with D. But maybe, just maybe, she has gotten a completely different idea by then. Maybe she wants work to continue on F. And after B it´s neither D nor E, but G. And after G it´s D. With Spinning every 32 hours at latest priorities can be changed. And nothing is lost. Because what got accepted is of value. It provides an incremental value to the customer/user. Or it provides internal value to the Product Owner as increased knowledge/decreased uncertainty. I find such reactivity over commitment economically very benefical. Why commit a team to some workload for several weeks? It´s unnecessary at beast, and inflexible and wasteful at worst. If we cannot promise delivery of a certain scope on a certain date - which is what customers/management usually want -, we can at least provide them with unpredecented flexibility in the face of high uncertainty. Where the path is not clear, cannot be clear, make small steps so you´re able to change your course at any time. Premature completion Customers/management are used to premeditating budgets. They want to know exactly how much to pay for a certain amount of requirements. That´s understandable. But it does not match with the nature of software development. We should know that by now. Maybe there´s somewhere in the world some team who can consistently deliver on scope, quality, and time, and budget. Great! Congratulations! I, however, haven´t seen such a team yet. Which does not mean it´s impossible, but I think it´s nothing I can recommend to strive for. Rather I´d say: Don´t try this at home. It might hurt you one way or the other. However, what we can do, is allow customers/management stop work on features at any moment. With spinning every 32 hours a feature can be declared as finished - even though it might not be completed according to initial definition. I think, progress over completion is an important offer software development can make. Why think in terms of completion beyond a promise for the next 32 hours? Isn´t it more important to constantly move forward? Step by step. We´re not running sprints, we´re not running marathons, not even ultra-marathons. We´re in the sport of running forever. That makes it futile to stare at the finishing line. The very concept of a burn-down chart is misleading (in most cases). Whoever can only think in terms of completed requirements shuts out the chance for saving money. The requirements for a features mostly are uncertain. So how does a Product Owner know in the first place, how much is needed. Maybe more than specified is needed - which gets uncovered step by step with each finished increment. Maybe less than specified is needed. After each 4–32 hour increment the Product Owner can do an experient (or invite users to an experiment) if a particular trait of the software system is already good enough. And if so, she can switch the attention to a different aspect. In the end, requirements A, B, C then could be finished just 70%, 80%, and 50%. What the heck? It´s good enough - for now. 33% money saved. Wouldn´t that be splendid? Isn´t that a stunning argument for any budget-sensitive customer? You can save money and still get what you need? Pull on practices So far, in addition to more trust, more flexibility, less money spent, Spinning led to “doing less” which also means less code which of course means higher Evolvability per se. Last but not least, though, I think Spinning´s short acceptance cycles have one more effect. They excert pull-power on all sorts of practices known for increasing Evolvability. If, for example, you believe high automated test coverage helps Evolvability by lowering the fear of inadverted damage to a code base, why isn´t 90% of the developer community practicing automated tests consistently? I think, the answer is simple: Because they can do without. Somehow they manage to do enough manual checks before their rare releases/acceptance checks to ensure good enough correctness - at least in the short term. The same goes for other practices like component orientation, continuous build/integration, code reviews etc. None of that is compelling, urgent, imperative. Something else always seems more important. So Evolvability principles and practices fall through the cracks most of the time - until a project hits a wall. Then everybody becomes desperate; but by then (re)gaining Evolvability has become as very, very difficult and tedious undertaking. Sometimes up to the point where the existence of a project/company is in danger. With Spinning that´s different. If you´re practicing Spinning you cannot avoid all those practices. With Spinning you very quickly realize you cannot deliver reliably even on your 32 hour promises. Spinning thus is pulling on developers to adopt principles and practices for Evolvability. They will start actively looking for ways to keep their delivery rate high. And if not, management will soon tell them to do that. Because first the Product Owner then management will notice an increasing difficulty to deliver value within 32 hours. There, finally there emerges a way to measure Evolvability: The more frequent developers tell the Product Owner there is no way to deliver anything worth of feedback until tomorrow night, the poorer Evolvability is. Don´t count the “WTF!”, count the “No way!” utterances. In closing For sustainable software development we need to put Evolvability first. Functionality and Quality must not rule software development but be implemented within a framework ensuring (enough) Evolvability. Since Evolvability cannot be measured easily, I think we need to put software development “under pressure”. Software needs to be changed more often, in smaller increments. Each increment being relevant to the customer/user in some way. That does not mean each increment is worthy of shipment. It´s sufficient to gain further insight from it. Increments primarily serve the reduction of uncertainty, not sales. Sales even needs to be decoupled from this incremental progress. No more promises to sales. No more delivery au point. Rather sales should look at a stream of accepted increments (or incremental releases) and scoup from that whatever they find valuable. Sales and marketing need to realize they should work on what´s there, not what might be possible in the future. But I digress… In my view a Spinning cycle - which is not easy to reach, which requires practice - is the core practice to compensate the immeasurability of Evolvability. From start to finish of each issue in 32 hours max - that´s the challenge we need to accept if we´re serious increasing Evolvability. Fortunately higher Evolvability is not the only outcome of Spinning. Customer/management will like the increased flexibility and “getting more bang for the buck”.

    Read the article

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

< Previous Page | 58 59 60 61 62 63 64 65 66 67 68 69  | Next Page >