Search Results

Search found 8012 results on 321 pages for 'max li'.

Page 203/321 | < Previous Page | 199 200 201 202 203 204 205 206 207 208 209 210  | Next Page >

  • c++ property class structure

    - by Without me Its just Aweso
    I have a c++ project being developed in QT. The problem I'm running in to is I am wanting to have a single base class that all my property classes inherit from so that I can store them all together. Right now I have: class AbstractProperty { public: AbstractProperty(QString propertyName); virtual QString toString() const = 0; virtual QString getName() = 0; virtual void fromString(QString str) = 0; virtual int toInteger() = 0; virtual bool operator==(const AbstractProperty &rightHand) = 0; virtual bool operator!=(const AbstractProperty &rightHand) = 0; virtual bool operator<(const AbstractProperty &rightHand) = 0; virtual bool operator>(const AbstractProperty &rightHand) = 0; virtual bool operator>=(const AbstractProperty &rightHand) = 0; virtual bool operator<=(const AbstractProperty &rightHand) = 0; protected: QString name; }; then I am implementing classes such as PropertyFloat and PropertyString and providing implementation for the comparator operators based on the assumption that only strings are being compared with strings and so on. However the problem with this is there would be no compiletime error thrown if i did if(propertyfloat a < propertystring b) however my implementation of the operators for each derived class relies on them both being the same derived class. So my problem is I cant figure out how to implement a property structure so that I can have them all inherit from some base type but code like what I have above would throw a compile time error. Any ideas on how this can be done? For those familiar with QT I tried using also a implementation with QVariant however QVariant doesn't have operators < and defined in itself only in some of its derived classes so it didn't work out. What my end goal is, is to be able to generically refer to properties. I have an element class that holds a hashmap of properties with string 'name' as key and the AbstractProperty as value. I want to be able to generically operate on the properties. i.e. if I want to get the max and min values of a property given its string name I have methods that are completely generic that will pull out the associated AbstactProperty from each element and find the max/min no matter what the type is. so properties although initially declared as PropertyFloat/PropertyString they will be held generically.

    Read the article

  • Will First() perform the OrderBy()?

    - by Martin
    Is there any difference in (asymptotic) performance between Orders.OrderBy(order => order.Date).First() and Orders.Where(order => order.Date == Orders.Max(x => x.Date)); i.e. will First() perform the OrderBy()? I'm guessing no. MSDN says enumerating the collection via foreach och GetEnumerator does but the phrasing does not exclude other extensions.

    Read the article

  • Are C++ enums signed or unsigned?

    - by Matt
    Are C++ enums signed or unsigned? And by extension is it safe to validate an input by checking that it is <= your max value, and leave out = your min value (assuming you started at 0 and incremented by 1)?

    Read the article

  • Manually Increasing the Amount of CPU a Java Application Uses

    - by SkylineAddict
    I've just made a program with Eclipse that takes a really long time to execute. It's taking even longer because it's loading my CPU to 25% only (I'm assuming that is because I'm using a quad-core and the program is only using one core). Is there any way to make the program use all 4 cores to max it out? Java is supposed to be natively multi-threaded, so I don't understand why it would only use 25%.

    Read the article

  • Details to log when starting an application

    - by Karl
    To help support and anyone who may use one of my applications I tend to log a few things during the application startup. Currently I log: Start Time App Name App Author App Version App Classpath Current working directory Java vendor Java version Max heap size Taking into consideration this application may be used / supported by a whole host of people can anyone think of any other vital details which we / others should log for good practice?

    Read the article

  • .htaccess & mod_rewrite for passing GET parameters

    - by Joel Alejandro
    Currently I use this to pass GET parameters on an "elegant" way: RewriteEngine On RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteRule ^([^/]*)/$ index.php?module=$1 [L] RewriteRule ^([^/]*)/([^/]*)/$ index.php?module=$1&object=$2 [L] RewriteRule ^([^/]*)/([^/]*)/([^/]*)/$ index.php?module=$1&object=$2&submodule=$3 [L] This works great for 3 parameters max., (and I'm sure it's seriously ugly). Any way to do the same thing, for n-paremeters?

    Read the article

  • How to get only one record for each duplicate rows of the id in oracle?

    - by Psychocryo
    suppose i have this table: group_id | image | image_id | ----------------------------- 23 blob 1 23 blob 2 23 blob 3 21 blob 4 21 blob 5 25 blob 6 25 blob 7 how to get results of only 1 of each group id? in this case,there may be multiple images for one group id, i just want one result of each group_id i tried distinct but i will only get group_id. max for image also would not work.

    Read the article

  • Help with simple query - why isn't an index being used?

    - by Randy Minder
    I have the following query: SELECT MAX([LastModifiedTime]) FROM Workflow There are approximately 400M rows in the Workflow table. There is an index on the LastModifiedTime column as follows: CREATE NONCLUSTERED INDEX [IX_Workflow_LastModifiedTime] ON [dbo].[Workflow] ( [LastModifiedTime] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, IGNORE_DUP_KEY = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, FILLFACTOR = 100) The above query takes 1.5 minutes to execute. Why wouldn't SQL Server use the above index and simply retrieve the last row in the index to get the maximum value? Thanks.

    Read the article

  • Image classification: recognizing various features of many buildings from images

    - by el chief
    so, let's say i have the long/lat or address of many buildings can get satellite images, "street view", and perhaps 3d/perspective views of buildings. want to find: height, number of floors, floor area (max building footprint) of the building. about 200k buildings. Is there a library for recognizing buildings from satellite shots or pictures? Kind of like face detection I suppose. Any other suggestions? Thanks!

    Read the article

  • Problem intialising 2D array

    - by TeeJay
    Ok, so I have a 2D Array that is initialised with values from a file (format: x y z). My file reads in the values correctly but when adding the z value to the matrix/2DArray, I run into a segfault and I have no idea why. It is possibly incorrect use of pointers? I still don't quite have the hang of them yet. This is my intialiser, works fine, even intialises all "z" values to 0. int** make2DArray(int rows, int columns) { int** newArray; newArray = (int**)malloc(rows*sizeof(int*)); if (newArray == NULL) { printf("out of memory for newArray.\n"); } for (int i = 0; i < rows; i++) { newArray[i] = (int*)malloc(columns*sizeof(int)); if (newArray[i] == NULL) { printf("out of memory for newArray[%d].\n", i); } } //intialise all values to 0 for (int i = 0; i < rows; i++) { for (int j = 0; j < columns; j++) { newArray[i][j] = 0; } } return newArray; } This is how I call the initialiser (and problem function). int** map = make2DArray(rows, columns); fillMatrix(&map, mapFile); And this is the problem code. void fillMatrix(int*** inMatrix, FILE* inFile) { int x, y, z; char line[100]; while(fgets(line, sizeof(line), inFile) != NULL) { sscanf(line, "%d %d %d", &x, &y, &z); *inMatrix[x][y] = z; } } From what I can gather through the use of ddd, the problem comes when y gets to 47. The map file has a max "x" value of 47 and a max "y" value of 63, I'm pretty sure I haven't got the order mixed up, so I don't know why the program is segfault-ing? I'm sure it's some newbie mistake...

    Read the article

  • group by with value of another column

    - by phenevo
    Hi, I've got table Articles ID identity autoincement, IDArticle: nvarchar(100) ,IDCar nvarchar(100), createddate How to convert this: SELECT IDCar , MAX(createddate) FROM Articles GROUP BY IDCar to get IDArticle eg: 1 art1 BWM 5-21-2010 2 art2 BMW 5-24-2010 3 art3 BMW 5-31-2010 4 art4 Porshe 5-31-2010 5 art5 Porshe 6-1-2010 Expecting result is: art3 art5 It's not duplicated with: http://stackoverflow.com/questions/2736769/sql-query-number-of-occurance/2736809#2736809

    Read the article

  • How to automatically reseed after using identity_insert?

    - by Earlz
    Hello, I recently migrated from a PostgreSQL database to a SQL Server database. To switch the data over I had to enable IDENTITY_INSERT. Well come to find out that I get all sorts of strange errors due to duplicate identity values(which are set as primary keys) upon doing an insert in any of the tables. I have quite a few tables. What would be the easiest way of automatically reseeding the identity of every table so that it is after max(RID)?

    Read the article

  • Better mode for do a select with group by

    - by Luca Romagnoli
    Hi i've wrote a query that works: SELECT `comments`.* FROM `comments` RIGHT JOIN (SELECT MAX( id ) AS id, core_id, topic_id FROM comments GROUP BY core_id, topic_id order by id desc) comm ON comm.id = comments.id LIMIT 10 I want know if is possible and how rewrite it for get better performance. thanks

    Read the article

< Previous Page | 199 200 201 202 203 204 205 206 207 208 209 210  | Next Page >