Search Results

Search found 9706 results on 389 pages for 'aggregate functions'.

Page 158/389 | < Previous Page | 154 155 156 157 158 159 160 161 162 163 164 165  | Next Page >

  • Question About Example In Robert C Martin's _Clean Code_

    - by Jonah
    This is a question about the concept of a function doing only one thing. It won't make sense without some relevant passages for context, so I'll quote them here. They appear on pgs 37-38: To say this differently, we want to be able to read the program as though it were a set of TO paragraphs, each of which is describing the current level of abstraction and referencing subsequent TO paragraphs at the next level down. To include the setups and teardowns, we include setups, then we include the test page content, and then we include the teardowns. To include the setups, we include the suite setup if this is a suite, then we include the regular setup. It turns out to be very dif?cult for programmers to learn to follow this rule and write functions that stay at a single level of abstraction. But learning this trick is also very important. It is the key to keeping functions short and making sure they do “one thing.” Making the code read like a top-down set of TO paragraphs is an effective technique for keeping the abstraction level consistent. He then gives the following example of poor code: public Money calculatePay(Employee e) throws InvalidEmployeeType { switch (e.type) { case COMMISSIONED: return calculateCommissionedPay(e); case HOURLY: return calculateHourlyPay(e); case SALARIED: return calculateSalariedPay(e); default: throw new InvalidEmployeeType(e.type); } } and explains the problems with it as follows: There are several problems with this function. First, it’s large, and when new employee types are added, it will grow. Second, it very clearly does more than one thing. Third, it violates the Single Responsibility Principle7 (SRP) because there is more than one reason for it to change. Fourth, it violates the Open Closed Principle8 (OCP) because it must change whenever new types are added. Now my questions. To begin, it's clear to me how it violates the OCP, and it's clear to me that this alone makes it poor design. However, I am trying to understand each principle, and it's not clear to me how SRP applies. Specifically, the only reason I can imagine for this method to change is the addition of new employee types. There is only one "axis of change." If details of the calculation needed to change, this would only affect the submethods like "calculateHourlyPay()" Also, while in one sense it is obviously doing 3 things, those three things are all at the same level of abstraction, and can all be put into a TO paragraph no different from the example one: TO calculate pay for an employee, we calculate commissioned pay if the employee is commissioned, hourly pay if he is hourly, etc. So aside from its violation of the OCP, this code seems to conform to Martin's other requirements of clean code, even though he's arguing it does not. Can someone please explain what I am missing? Thanks.

    Read the article

  • Javascript file as an anonymous function

    - by Andrew Kou
    I have been reading a lot of Javascript lately and I have been noticing that the whole file is wrapped like the following in the .js files to be imported. (function() { ... code ... })() What is the reason for doing this rather than a simple set of constructor functions?

    Read the article

  • Getting the index of the returned max or min item using max()/min() on a list

    - by KevinGriffin
    I'm using Python's max and min functions on lists for a minimax algorithm, and I need the index of the value returned by max() or min(). In other words, I need to know which move produced the max (at a first player's turn) or min (second player) value. for i in range(9): newBoard = currentBoard.newBoardWithMove([i / 3, i % 3], player) if newBoard: temp = minMax(newBoard, depth + 1, not isMinLevel) values.append(temp) if isMinLevel: return min(values) else: return max(values) I need to be able to return the actual index of the min or max value, not just the value.

    Read the article

  • Offloading to HLSL/GPU without displaying?

    - by George R
    As far as I know, certain mathematical functions like FFTs and perlin noise, etc. can be much faster when done on the GPU as a pixel shader. My question is, if I wanted to exploit this to calculate results and stream to bitmaps, could I do it without needing to actually display it in Silverlight or something? More specifically, I was thinking of using this for large terrain generation involving lots of perlin and other noises, and post-processing like high passes and deriving normals from heightmaps, etc, etc.

    Read the article

  • JavaFX HTMLEditor - Insert image function

    - by Reshi
    I'm using JavaFX integrated HTMLEditor. All the functions that it has are fine but I need to have also the function of inserting an image inside the HTML text. Do you know some source which I could use? Or some other HTML (WYSIWYG) editor that could be used inside JavaFX and it has this functionality ? I can program this functionality into the existing JavaFX HTMLEditor by myself, but I prefer to ask before I start doing something :) Thank you very much for your answers ;)

    Read the article

  • QueryInterface fails at casting inside COM-interface implementation

    - by brecht
    I am creating a tool in c# to retrieve messages of a CAN-network (network in a car) using an Dll written in C/C++. This dll is usable as a COM-interface. My c#-formclass implements one of these COM-interfaces. And other variables are instantiated using these COM-interfaces (everything works perfect). The problem: The interface my C#-form implements has 3 abstract functions. One of these functions is called -by the dll- and i need to implement it myself. In this function i wish to retrieve a property of a form-wide variable that is of a COM-type. The COM library is CANSUPPORTLib The form-wide variable: private CANSUPPORTLib.ICanIOEx devices = new CANSUPPORTLib.CanIO(); This variable is also form-wide and is retrieved via the devices-variable: canreceiver = (CANSUPPORTLib.IDirectCAN2)devices.get_DirectDispatch(receiverLogicalChannel); The function that is called by the dll and implemented in c# public void Message(double dTimeStamp) { Console.WriteLine("!!! message ontvangen !!!" + Environment.NewLine); try { CANSUPPORTLib.can_msg_tag message = new CANSUPPORTLib.can_msg_tag(); message = (CANSUPPORTLib.can_msg_tag) System.Runtime.InteropServices.Marshal.PtrToStructure(canreceiver.RawMessage, message.GetType()); for (int i = 0; i < message.data.Length; i++) { Console.WriteLine("byte " + i + ": " + message.data[i]); } } catch (Exception e) { Console.WriteLine(e.Message); } } The error rises at this line: message = (CANSUPPORTLib.can_msg_tag)System.Runtime.InteropServices.Marshal.PtrToStructure(canreceiver.RawMessage, message.GetType()); Error: Unable to cast COM object of type 'System.__ComObject' to interface type 'CANSUPPORTLib.IDirectCAN2'. This operation failed because the QueryInterface call on the COM component for the interface with IID '{33373EFC-DB42-48C4-A719-3730B7F228B5}' failed due to the following error: No such interface supported (Exception from HRESULT: 0x80004002 (E_NOINTERFACE)). Notes: It is possible to have a timer-clock that checks every 100ms for the message i need. The message is then retrieved in the exact same way as i do now. This timer is started when the form starts. The checking is only done when Message(double) has put a variable to true (a message arrived). When the timer-clock is started in the Message function, i have the same error as above Starting another thread when the form starts, is also not possible. Is there someone with experience with COM-interop ? When this timer

    Read the article

  • ActionScipt MouseEvent's CLICK vs. DOUBLE_CLICK

    - by TheDarkIn1978
    is it not possible to have both CLICK and DOUBLE_CLICK on the same display object? i'm trying to have both for the stage where double clicking the stage adds a new object and clicking once on the stage deselects a selected object. it appears that DOUBLE_CLICK will execute both itself as well as 2 CLICK functions. in other languages i've programmed with there was a built-in timers that set the two apart. is this not available in AS3?

    Read the article

  • Select the latest record for each category linked available on an object

    - by Simpleton
    I have a tblMachineReports with the columns: Status(varchar),LogDate(datetime),Category(varchar), and MachineID(int). I want to retrieve the latest status update from each category for every machine, so in effect getting a snapshot of the latest statuses of all the machines unique to their MachineID. The table data would look like Category - Status - MachineID - LogDate cata - status1 - 001 - date1 cata - status2 - 002 - date2 catb - status3 - 001 - date2 catc - status2 - 002 - date4 cata - status3 - 001 - date5 catc - status1 - 001 - date6 catb - status2 - 001 - date7 cata - status2 - 002 - date8 catb - status2 - 002 - date9 catc - status2 - 001 - date10 Restated, I have multiple machines reporting on multiple statuses in this tblMachineReports. All the rows are created through inserts, so their will obviously be duplicate entries for machines as new statuses come in. None of the columns can be predicted, so I can't do any ='some hard coded string' comparisons in any part of the select statement. For the sample table I provided, the desired results would look like: Category - Status - MachineID - LogDate catc - status2 - 002 - date4 cata - status3 - 001 - date5 catb - status2 - 001 - date7 cata - status2 - 002 - date8 catb - status2 - 002 - date9 catc - status2 - 001 - date10 What would the select statement look like to achieve this, getting the latest status for each category on each machine, using MS SQL Server 2008? I have tried different combinations of subqueries combined with aggregate MAX(LogDates)'s, along with joins, group bys, distincts, and what-not, but have yet to find a working solution.

    Read the article

  • Tips on a tool to measure code quality?

    - by Cristi Diaconescu
    I'm looking for a tool that can provide code quality metrics. For instance it could report very long functions (spaghetti code) very complex classes (which could contain do-it-all code) ... While we're on the (subjective:-) subject of code quality, what other code metrics would you suggest? I'm targetting C#/.NET code, but I'm sure this could extend to most programming languages.

    Read the article

  • How to filter specific symbols(Only defined in dll/Exe/lib) using dia2dump

    - by Usman
    Hello, I need my all defined symbols (functions) in certain DLL/EXE/lib. I dont need Kernel or other OS layers symbols. I dont need all other stuf, only which's defined by my own DLL or EXE which I am giving it as PDB. But it shows EVERYTHING kernel related,OS related and balah blah endless list(sky is the limit).. I only required defined in my DLL, EXE or lib. How???? Regards Usman

    Read the article

  • two static libraries

    - by user295030
    Hi, I am currently providing a static library using vs2008. I am in the process of building my static library. However, since I am using another static library is there a way that then i package this as a single library. The reason here is that they will be calling functions in my library that depend on that other static library (.lib). I am not sure how to go about doing that and needs some help with that.

    Read the article

  • How to run nosetests from netbeans?

    - by Chris089
    I recently started using netbeans for python development and really like it. However, the test runner in netbeans does not run my doctests, nor does it run my test functions written using nose. I always have to switch to the shell and run 'setup.py test' or 'nosetests' manually. Is there a way to integrate this into netbenas 6.8?

    Read the article

  • pyQt4: QWidget subclass not responding to new setStyleSheet() background colour

    - by Ronny
    I am having an issue with PyQt4. I want to create a new widget within a window, and I want this widget to have a custom color. When i create a subclass of the QWidget class, and instantiate it, I am not able to change its background color through the setStyleSheet() function. When I instantiate a new QWidget object, I have no problems in changing its background color. But i dont want an ordinary QWidget object.I want to create my own subclass of QWidget. When i create a subclass of a QPushButton, I am also able to change its background color using the setStyleSheet() function. There are no error messages or warnings in the console window, it just refuses to work properly without any indication as to why. So what i would like to know is why is it that i can change the background color of a widget if i simply create a QWidget object, or a subclass of QPushButton, but not when i create a subclass of QWidget. And how can i therefore change the background color of an object that is a subclass of QWidget? Is it maybe something specific to the version of python or PyQt that i am using? Is it a bug in the library? or some flaw in the way that i am writing my code? I am using python 2.6.4 and PyQt4 Below is an example of the code that leads me to trouble. There are three widgets within the window one below the other. The parent widget is set with background color of green. The top widget is set to red, the middle one, is the subclass of QWidget, which should be blue, but it appears invisible because it takes on the color of the parent window for some reason. and the bottom widget is a subclass of QPushButton and is white. import sys from PyQt4 import QtGui, QtCore ################################################################################ #--------------------------------------------------------- CUSTOM WIDGET CLASS 1 class CustomWidget(QtGui.QWidget): def __init__(self, parent): QtGui.QWidget.__init__(self, parent) # some custom properties and functions will follow ################################################################################ #--------------------------------------------------------- CUSTOM WIDGET CLASS 2 class CustomWidget2(QtGui.QPushButton): def __init__(self, parent): QtGui.QPushButton.__init__(self, parent) # some custom properties and functions will follow ################################################################################ #----------------------------------------------------------- PARENT WIDGET CLASS class Parent(QtGui.QWidget): def __init__(self, parent=None): #---------------------------------------------------------- SETUP WINDOW QtGui.QWidget.__init__(self, parent) self.resize(500, 340) self.setStyleSheet("QWidget {background-color: #00FF00}") #-------------------------------------------------- SETUP DEFAULT WIDGET wid1 = QtGui.QWidget(self) wid1.setGeometry(10, 10, 480, 100) wid1.setStyleSheet("QWidget {background-color: #FF0000 }") #------------------------------------------------- SETUP CUSTOM WIDGET 1 wid2 = CustomWidget(self) wid2.setGeometry(10, 120, 480, 100) wid2.setStyleSheet("QWidget {background-color: #0000FF }") for i in dir(wid2): print i #------------------------------------------------- SETUP CUSTOM WIDGET 2 wid3 = CustomWidget2(self) wid3.setGeometry(10, 230, 480, 100) wid3.setStyleSheet("QWidget {background-color: #FFFFFF }") ################################################################################ #-------------------------------------------------------------------------- MAIN app = QtGui.QApplication(sys.argv) win = Parent() win.show() app.exec_()

    Read the article

  • how to code referral system in wordpress ?

    - by justjoe
    I'm just asking about custom feature I'm working on. If you have experience creating similar projects, what are things that need to be considered when creating similar features? PS: this is broad general question. And not something that focuses on a particular web system. And mostly will be code in PHP and wordpress. And frankly, I tend to code this not using Wordpress built-in functions.

    Read the article

  • Is there a C# library that will perform the Excel NORMINV function?

    - by Portman
    I'm running some Monte Carlo simulations and making extensive use of the Excel function NORM.INV using Office Interrop. This functions takes three arguments (probability, average, standard deviation) and returns the inverse of the cumulative distribution. I'd like to move my code into a web app, but that will require installing Excel on the server. Does anybody know of a C# statistics library that has an equivalent function to NORM.INV?

    Read the article

  • form validation with jquery

    - by kalpaitch
    I am having some issues with a jQuery form validation pluggin. Below is the code which executes on document.ready() $("#register").validate({ rules: { usernameREG: { required: true, remote: "PHP/checkUsr.php", minlength: 4} fnameREG: { required: true} lnameREG: { required: true} password1REG: { required: true, minlength: 4} password2REG: { equalTo: "#password1REG", required: true} emailREG: { required: true, email: true} telREG: { required: true, rangelength: [9, 13]} } }); Even without the 'rules' parameters this function does not trigger. It also stops all the proceeding jquery functions which are triggered on document.ready()

    Read the article

  • opengl paint program based on Apple's 'glPaint' on a white background - how to blend?

    - by Adam
    Trying to write a simple paint program for iPhone, and I'm using Apple's glPaint sample as a guide. The only problem is, painting doesn't work on a white background, since white + colour = white. I've tried different blending functions, but haven't been able to hit on the right combination of settings and/or brushes to make this work. I've seen similar posts about this problem but no answers. Does anyone know how this might work?

    Read the article

  • Generate a random alphanumeric string in cocoa

    - by Ward
    Hey there, I know this can't be that hard. I've searched, but I can't seem to find a simple solution. I want to call a method, pass it the length and have it generate a random alphanumeric string. Any ideas? Are there any utility libraries out there that may have a bunch of these types of functions? Thanks, Howie

    Read the article

  • [NAnt] About "nant::get-base-directory()"

    - by Nam Gi VU
    As in http://nant.sourceforge.net/release/latest/help/functions/nant.get-base-directory.html, they explaint the meaning of this function is: The base directory of the appdomain in which NAnt is running. I don't know what does appdomain mean! Someone please explain it for me. Thank you.

    Read the article

  • Parallel WCF calls to multiple servers

    - by gregmac
    I have a WCF service (the same one) running on multiple servers, and I'd like to call all instances in parallel from a single client. I'm using ChannelFactory and the interface (contract) to call the service. Each service has a local <endpoint> client defined in the .config file. What I'm trying to do is build some kind of generic framework to avoid code duplication. For example a synchronous call in a single thread looks something like this: Dim remoteName As String = "endpointName1" Dim svcProxy As ChannelFactory(Of IMyService) = New ChannelFactory(Of IMyService)(remoteName) Try svcProxy.Open() Dim svc As IMyService = svcProxy.CreateChannel() nodeResult = svc.TestRemote("foo") Finally svcProxy.Close() End Try The part I'm having difficulty with is how to specify and actually invoke the actual remote method (eg "TestRemote") without having to duplicate the above code, and all the thread-related stuff that invokes that, for each method. In the end, I'd like to be able to write code along the lines of (consider this psuedo code): Dim results as Dictionary(Of Node, ExpectedReturnType) results = ParallelInvoke(IMyService.SomeMethod, parameter1, parameter2) where ParallelInvoke() will take the method as an argument, as well as the parameters (paramArray or object() .. whatever) and then go run the request on each remote node, block until they all return an answer or timeout, and then return the results into a Dictionary with the key as the node, and the value as whatever value it returned. I can then (depending on the method) pick out the single value I need, or aggregate all the values from each server together, etc. I'm pretty sure I can do this using reflection and InvokeMember(), but that requires passing the method as a string (which can lead to errors like calling a non-existing method that can't be caught at compile time), so I'd like to see if there is a cleaner way to do this. Thanks

    Read the article

  • what is programming paradigm in haskell

    - by Pradeep
    im preparing for my exam. i got this question and i read several articles about this. but still i cant get a proper idea about this question what Paradigm means is that different programming styles ( as far as i think) in the question they ask explain it by taking two paradigms so this explanation should be done using two styles of programming "List Comprehnsions or Primitive Recursion, Higher order functions " is these styles are programming paradigms?? please help me

    Read the article

< Previous Page | 154 155 156 157 158 159 160 161 162 163 164 165  | Next Page >