Search Results

Search found 3758 results on 151 pages for 'efficient'.

Page 31/151 | < Previous Page | 27 28 29 30 31 32 33 34 35 36 37 38  | Next Page >

  • What is the fastest way to trim blank lines from beginning and end of array?

    - by Edward Tanguay
    This script: <?php $lines[] = ''; $lines[] = 'first line '; $lines[] = 'second line '; $lines[] = ''; $lines[] = 'fourth line'; $lines[] = ''; $lines[] = ''; $lineCount = 1; foreach($lines as $line) { echo $lineCount . ': [' . trim($line) . ']<br/>'; $lineCount++; } ?> produces this output: 1: [] 2: [first line] 3: [second line] 4: [] 5: [fourth line] 6: [] 7: [] What is the fastest, most efficient way to change the above script so that it also deletes the preceding and trailing blank entries but not the interior blank entries so that it outputs this: 1: [first line] 2: [second line] 3: [] 4: [fourth line] I could use the foreach loop but I imagine there is a way with array_filter or something similar which is much more efficient.

    Read the article

  • Perfect hash in Scala.

    - by Lukasz Lew
    I have some class C: class C (...) { ... } I want to use it to index an efficient map. The most efficient map is an Array. So I add a "global" "static" counter in companion object to give each object unique id: object C { var id_counter = 0 } In primary constructor of C, with each creation of C I want to remember global counter value and increase it. Question 1: How to do it? Now I can use id in C objects as perfect hash to index array. But array does not preserve type information like map would, that a given array is indexed by C's id. Question 2: Is it possible to have it with type safety?

    Read the article

  • Why are nanosleep() and usleep() too slow?

    - by user351990
    I have a program that generates packets to send to a receiver. I need an efficient method of introducing a small delay between the sending of each packet so as not to overrun the receiver. I've tried usleep() and nanosleep() but they seem to be too slow. I've implemented a busy wait loop and had more success, but it's not the most efficient method, I know. I'm interested in anyone's experiences in trying to do what I'm doing. Do others find usleep() and nanosleep() to function well for this type of application? Thanks, Danny Llewallyn

    Read the article

  • Hbase schema design -- to make sorting easy?

    - by chen
    I have 1M words in my dictionary. Whenever a user issue a query on my website, I will see if the query contains the words in my dictionary and increment the counter corresponding to them individually. Here is the example, say if a user type in "Obama is a president" and "Obama" and "president" are in my dictionary, then I should increment the counter by 1 for "Obama" and "president". And from time to time, I want to see the top 100 words (most queried words). If I use Hbase to store the counter, what schema should I use? -- I have not come up an efficient one yet. If I use word in my dictionary as row key, and "counter" as column key, then updating counter(increment) is very efficient. But it's very hard to sort and return the top 100. Anyone can give a good advice? Thanks.

    Read the article

  • Can I interpolate two HEX color values without converting them to RGB?

    - by navand
    I'm trying to make a Gradient Class for a Blackberry app. At first I thought about converting the HEX values to RGB and then interpolating them before converting the result back into HEX, but since I will be doing this for every pixel line of an area, and the calculations will be made by a mobile, I thought that maybe there's a more efficient way of doing it. Maybe involving those pesky bitwise operators which I know nothing of... or something. So, is there a way of interpolating without converting to RGB and back? If so, is it faster than the original way? In any case, can you help me make the most efficient color interpolation? Thank you in advance!

    Read the article

  • Tag Suggestion system, approaches and ideas

    - by Galois
    Hi guys! -- I am working on a (auto) tag suggestion system (NOT tag autocomplete). Lets say I want to suggest tags for a given question like here on SO (although SO's tagging system is auto-complete). My main idea is to get the intersection between the tags_set and the given question.split()_set. (In python the set_intersection is efficient enough). Also, in order to make it a little bit more accurate I might use words-distance to count as 'the same' very close words i.e movie == movies. For now I am not thinking about using any Collaborative Filtering technique looking for the tags to similar questions and so on, because I believe since the question text is pretty short (comparing with a blog article or a paper) it is not worth the effort. So I was wondering if you have any other (more) efficient approaches to suggest. Any ideas, specially from people who they have done something like that before, are more than welcome.

    Read the article

  • Random List of millions of elements in Python Efficiently

    - by eWizardII
    Hello, I have read this answer potentially as the best way to randomize a list of strings in Python. I'm just wondering then if that's the most efficient way to do it because I have a list of about 30 million elements via the following code: import json from sets import Set from random import shuffle a = [] for i in range(0,193): json_data = open("C:/Twitter/user/user_" + str(i) + ".json") data = json.load(json_data) for j in range(0,len(data)): a.append(data[j]['su']) new = list(Set(a)) print "Cleaned length is: " + str(len(new)) ## Take Cleaned List and Randomize it for Analysis shuffle(new) If there is a more efficient way to do it, I'd greatly appreciate any advice on how to do it. Thanks,

    Read the article

  • Performance of Managed C++ Vs UnManaged/native C++

    - by bsobaid
    I am writing a very high performance application that handles and processes hundreds of events every millisecond. Is Unmanaged C++ faster than managed c++? and why? Managed C++ deals with CLR instead of OS and CLR takes care of memory management, which simplifies the code and is probably also more efficient than code written by "a programmer" in unmanaged C++? or there is some other reason? When using managed, how can one then avoid dynamic memory allocation, which causes a performance hit, if it is all transparent to the programmer and handled by CLR? So coming back to my question, Is managed C++ more efficient in terms of speed than unmanaged C++ and why?

    Read the article

  • Operator + for matrices in C++

    - by cibercitizen1
    I suppose the naive implementation of a + operator for matrices (2D for instance) in C++ would be: class Matrix { Matrix operator+ (Matrix other) const { Matrix result; // fill result with *this.data plus other.data return result; } } so we could use it like Matrix a; Matrix b; Matrix c; c = a + b; Right? But if matrices are big this is not efficient as we are doing one not-necessary copy (return result). Therefore, If we wan't to be efficient we have to forget the clean call: c = a + b; Right? What would you suggest / prefer ? Thanks.

    Read the article

  • Fitting maximum amount of shapes on a surface

    - by Fuu
    In industry, there is often a problem where you need to calculate the most efficient use of material, be it fabric, wood, metal etc. So the starting point is X amount of shapes of given dimensions, made out of polygons and/or curved lines, and target is another polygon of given dimensions. I assume many of the current CAM suites implement this, but having no experience using them or of their internals, what kind of computational algorithm is used to find the most efficient use of space? Can someone point me to a book or other reference that discusses this subject?

    Read the article

  • String Occurance Counting Algorithm

    - by Hellnar
    Hello, I am curious what is the most efficient algorithm (or commonly used) to count the number of occurances of a string in a chunck of text. From what I read, Boyer–Moore string search algorithm is the standard for string search but I am not sure if counting occurance in an efficient way would be same as searching a string. In python this is what I want: text_chunck = "one two three four one five six one" occurance_count(text_chunck, "one") # gives 3. Regards EDIT: It seems like python str.count serves me such method however I am not able to find what algorithm it uses.

    Read the article

  • Why is writing a compiler in a functional language easier?

    - by wvd
    Hello all, I've been thinking of this question very long, but really couldn't find the answer on Google as well a similar question on Stackoverflow. If there is a duplicate, I'm sorry for that. A lot of people seem to say that writing compilers and other language tools in functional languages such as OCaml and Haskell is much more efficient and easier then writing them in imperative languages. Is this true? And if so -- why is it so efficient and easy to write them in functional languages instead of in an imperative language, like C? Also -- isn't a language tool in a functional language slower then in some low-level language like C? Thanks in advance, William v. Doorn

    Read the article

  • Is it inefficient to access a python class member container in a loop statement?

    - by Dave
    Hi there. I'm trying to adopt some best practices to keep my python code efficient. I've heard that accessing a member variable inside of a loop can incur a dictionary lookup for every iteration of the loop, so I cache these in local variables to use inside the loop. My question is about the loop statement itself... if I have the following class: class A(object): def init(self) self.myList = [ 'a','b','c', 'd', 'e' ] Does the following code in a member function incur one, or one-per-loop-iteration (5) dictionary lookups? for letter in self.myList: print letter IE, should I adopt the following pattern, if I am concerned about efficiency... localList = self.myList for letter in localList: print letter or is that actually LESS efficient due to the local variable assign? Note, I am aware that early optimization is a dangerous pitfall if I'm concerned about the overall efficiency of code development. Here I am specifically asking about the efficiency of the code, not the coding. Thanks in advance! D

    Read the article

  • How is fseek() implemented in the filesystem?

    - by pajton
    This is not a pure programming question, however it impacts the performance of programs using fseek(), hence it is important to know how it works. A little disclaimer so that it doesn't get closed. I am wondering how efficient it is to insert data in the middle of the file. Supposing I have a file with 1MB data and then I insert something at the 512KB offset. How efficient would that be compared to appending my data at the end of the file? Just to make the example complete lets say I want to insert 16KB of data. I understand the answer varies depending on the filesystem, however I assume that the techniques used in common filesystems are quite similar and I just want to get the right notion of it.

    Read the article

  • Should I dive into ASP.NET MVC or start with ASP.NET Webforms?

    - by Sahat
    I plan to pick up Silverlight in the future. Possibility of going into Microsoft WPF. Currently learning Objective-C 2.0 w/ Cocoa. I already know Pros and Cons of ASP.NET MVC vs ASP.NET Webforms. What I want to know is what would be more "efficient" for me to learn given the circumstances above? By efficient I mean learning one design pattern once and then re-using it. Objective-C I believe uses MVC approach? What about Silverlight? WPF? So what do you think? Also as a side question is it true that ASP.NET Webforms is often used by freelancers/small companies and ASP.NET MVC in large enterprises?

    Read the article

  • Hibernate Hql find result size for paginator

    - by KCore
    Hi, I need to add paginator for my Hibernate application. I applied it to some of my database operations which I perform using Criteria by setting Projection.count().This is working fine. But when I use hql to query, I can't seem to get and efficient method to get the result count. If I do query.list().size() it takes lot of time and I think hibernate does load all the objects in memory. Can anyone please suggest an efficient method to retrieve the result count when using hql?

    Read the article

  • Flash Media Server dynamic file naming

    - by flying_tiger
    I'm trying to figure out most efficient/safe way to name recorded streams on FMS. The case is to get listing of recorded streams from the server (eg. rec_001, rec_002...) and dynamically add rec_003 filename to the new stream that is being recorded. I'm thinking about either using FMS File Object and put everything in array of files every time I start recording procedure or to create XML file that would serve as a database of file names. I'm searching for a solution efficient for MULTIPLE connections at a time and large amount of files. Which one of presented would be the best for this purpose? Or do you have any better suggestions of solving this problem?

    Read the article

  • How to close a form in UserControl

    - by FJPoort
    I created a UserControl with the buttons Save, Close and Cancel. I want to close the form without saving on the Cancel button, prompt a message to save on the Close button and Save without closing on the Save button. Normally, I would have used this.Close() on the Cancel button, but the UserControl doesn't have such an option. So I guess I have to set a property for that. Scrolling down the "Questions that may already have your answer" section, I came across this question: How to close a ChildWindow from an UserControl button loaded inside it? I used the following C# code: private void btnCancel_Click(object sender, EventArgs e) { ProjectInfo infoScreen = (ProjectInfo)this.Parent; infoScreen.Close(); } This does the job for one screen, but I wonder if I have to apply this code for all the screen I have? I think there should be a more efficient way. So my question is: Do I need to apply this code for every form I have, or is there another (more efficient) way?

    Read the article

  • Using a large list of terms, search through page text and replace words with links

    - by dunc
    A while ago I posted this question asking if it's possible to convert text to HTML links if they match a list of terms from my database. I have a fairly huge list of terms - around 6000. The accepted answer on that question was superb, but having never used XPath, I was at a loss when problems started occurring. At one point, after fiddling with code, I somehow managed to add over 40,000 random characters to our database - the majority of which required manual removal. Since then I've lost faith in that idea and the more simple PHP solutions simply weren't efficient enough to deal with the amount of data and the quantity of terms. My next attempt at a solution is to write a JS script which, once the page has loaded, retrieves the terms and matches them against the text on a page. This answer has an idea which I'd like to attempt. I would use AJAX to retrieve the terms from the database, to build an object such as this: var words = [ { word: 'Something', link: 'http://www.something.com' }, { word: 'Something Else', link: 'http://www.something.com/else' } ]; When the object has been built, I'd use this kind of code: //for each array element $.each(words, function() { //store it ("this" is gonna become the dom element in the next function) var search = this; $('.message').each( function() { //if it's exactly the same if ($(this).text() === search.word) { //do your magic tricks $(this).html('<a href="' + search.link + '">' + search.link + '</a>'); } } ); } ); Now, at first sight, there is a major issue here: with 6,000 terms, will this code be in any way efficient enough to do what I'm trying to do?. One option would possibly be to perform some of the overhead within the PHP script that the AJAX communicates with. For instance, I could send the ID of the post and then the PHP script could use SQL statements to retrieve all of the information from the post and match it against all 6,000 terms.. then the return call to the JavaScript could simply be the matching terms, which would significantly reduce the number of matches the above jQuery would make (around 50 at most). I have no problem with the script taking a few seconds to "load" on the user's browser, as long as it isn't impacting their CPU usage or anything like that. So, two questions in one: Can I make this work? What steps can I take to make it as efficient as possible? Thanks in advance,

    Read the article

  • How to reverse a dictionary that it has repeated values (python)

    - by Galois
    Hi guys! So, I have a dictionary with almost 100,000 (key, values) pairs and the majority of the keys map to the same values. For example imagine something like that: dict = {'a': 1, 'c': 2, 'b': 1, 'e': 2, 'd': 3, 'h': 1, 'j': 3} What I want to do, is to reverse the dictionary so that each value in dict is going to be a key at the reverse_dict and is going to map to a list of all the dict.keys that used to map to that value at the dict. So based on the example above I would get: reversed_dict = {1: ['a', 'b', 'h'], 2:['e', 'c'] , 3:['d', 'j']} I came up with a solution that is very expensive and I would really want to hear any ideas more efficient than mine. my expensive solution: reversed_dict = {} for value in dict.values(): reversed_dict[value] = [] for key in dict.keys(): if dict[key] == value: if key not in reversed_dict[value]: reversed_dict[value].append(key) Output >> reversed_dict = {1: ['a', 'b', 'h'], 2: ['c', 'e'], 3: ['d', 'j']} I would really appreciate to hear any ideas better and more efficient than than mine. Thanks!

    Read the article

< Previous Page | 27 28 29 30 31 32 33 34 35 36 37 38  | Next Page >