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Search found 647 results on 26 pages for 'rand mate'.

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  • C++ random number from a set

    - by user69514
    Is it possible to print a random number in C++ from a set of numbers with ONE SINGLE statement? let's say the set is 2, 5, 22, 55, 332 i looked up rand, but I double it's possible to do in a single statement

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  • Euclidian Distances between points

    - by R S
    I have an array of points in numpy: points = rand(dim, n_points) And I want to: Calculate all the l2 norm (euclidian distance) between a certain point and all other points Calculate all pairwise distances. and preferably all numpy and no for's.

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  • Does MySQL short-circuit the ORDER BY clause?

    - by nickf
    Given this SQL: SELECT * FROM mytable ORDER BY mycolumn, RAND() Assuming that mycolumn happens to only contain unique values (and hence, contains enough information to perform the ORDER BY), does MySQL short-circuit the operation and skip evaluating the rest?

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  • Need help converting Ruby code to php code

    - by newprog
    Yesterday I posted this queston. Today I found the code which I need but written in Ruby. Some parts of code I have understood (I don't know Ruby) but there is one part that I can't. I think people who know ruby and php can help me understand this code. def do_create(image) # Clear any old info in case of a re-submit FIELDS_TO_CLEAR.each { |field| image.send(field+'=', nil) } image.save # Compose request vm_params = Hash.new # Submitting a file in ruby requires opening it and then reading the contents into the post body file = File.open(image.filename_in, "rb") # Populate the parameters and compute the signature # Normally you would do this in a subroutine - for maximum clarity all # parameters are explicitly spelled out here. vm_params["image"] = file # Contents will be read by the multipart object created below vm_params["image_checksum"] = image.image_checksum vm_params["start_job"] = 'vectorize' vm_params["image_type"] = image.image_type if image.image_type != 'none' vm_params["image_complexity"] = image.image_complexity if image.image_complexity != 'none' vm_params["image_num_colors"] = image.image_num_colors if image.image_num_colors != '' vm_params["image_colors"] = image.image_colors if image.image_colors != '' vm_params["expire_at"] = image.expire_at if image.expire_at != '' vm_params["licensee_id"] = DEVELOPER_ID #in php it's like this $vm_params["sequence_number"] = -rand(100000000);????? vm_params["sequence_number"] = Kernel.rand(1000000000) # Use a negative value to force an error when calling the test server vm_params["timestamp"] = Time.new.utc.httpdate string_to_sign = CREATE_URL + # Start out with the URL being called... #vm_params["image"].to_s + # ... don't include the file per se - use the checksum instead vm_params["image_checksum"].to_s + # ... then include all regular parameters vm_params["start_job"].to_s + vm_params["image_type"].to_s + vm_params["image_complexity"].to_s + # (nil.to_s => '', so this is fine for vm_params we don't use) vm_params["image_num_colors"].to_s + vm_params["image_colors"].to_s + vm_params["expire_at"].to_s + vm_params["licensee_id"].to_s + # ... then do all the security parameters vm_params["sequence_number"].to_s + vm_params["timestamp"].to_s vm_params["signature"] = sign(string_to_sign) #no problem # Workaround class for handling multipart posts mp = Multipart::MultipartPost.new query, headers = mp.prepare_query(vm_params) # Handles the file parameter in a special way (see /lib/multipart.rb) file.close # mp has read the contents, we can close the file now response = post_form(URI.parse(CREATE_URL), query, headers) logger.info(response.body) response_hash = ActiveSupport::JSON.decode(response.body) # Decode the JSON response string ##I have understood below def sign(string_to_sign) #logger.info("String to sign: '#{string_to_sign}'") Base64.encode64(HMAC::SHA1.digest(DEVELOPER_KEY, string_to_sign)) end # Within Multipart modul I have this: class MultipartPost BOUNDARY = 'tarsiers-rule0000' HEADER = {"Content-type" => "multipart/form-data, boundary=" + BOUNDARY + " "} def prepare_query (params) fp = [] params.each {|k,v| if v.respond_to?(:read) fp.push(FileParam.new(k, v.path, v.read)) else fp.push(Param.new(k,v)) end } query = fp.collect {|p| "--" + BOUNDARY + "\r\n" + p.to_multipart }.join("") + "--" + BOUNDARY + "--" return query, HEADER end end end Thanks for your help.

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  • Java How to get exact tile location in random tile engine

    - by SYNYST3R1
    I am using the slick2d library. I want to know how to get the exact tile location so when I click on a tile it only changes that tile and not every tile on the screen. My tile generation class public Image[] tiles = new Image[3]; public int width, height; public int[][] index; public Image grass, dirt, selection; boolean selected; int mouseX, mouseY; public void init() throws SlickException { grass = new Image("assets/tiles/grass.png"); dirt = new Image("assets/tiles/dirt.png"); selection = new Image("assets/tiles/selection.png"); tiles[0] = grass; tiles[1] = dirt; width = 50; height = 50; index = new int[width][height]; Random rand = new Random(); for (int x = 0; x < width; x++) { for (int y = 0; y < height; y++) { index[x][y] = rand.nextInt(2); } } } public void update(GameContainer gc) { Input input = gc.getInput(); mouseX = input.getMouseX(); mouseY = input.getMouseY(); if(input.isMouseButtonDown(Input.MOUSE_LEFT_BUTTON)) { selected = true; } else{ selected = false; } } public void render() { for (int x = 0; x < width; x++) { for (int y = 0; y < height; y++) { tiles[index[x][y]].draw(x * 64, y *64); if(IsMouseInsideTile(x, y)) selection.draw(x * 64, y * 64); } } } public boolean IsMouseInsideTile(int x, int y) { return (mouseX >= x * 64 && mouseX <= (x + 1) * 64 && mouseY >= y * 64 && mouseY <= (y + 1) * 64); } I have tried a couple different ways to change the tile I am clicking on, but I don't understand how to do it.

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  • Naming member functions/methods with a single underscore, good style or bad?

    - by Extrakun
    In some languages where you cannot override the () operator, I have seen methods with a single underscore, usually for 'helper' classes. Something likes this: class D10 { public function _() { return rand(1,10); } } Is it better to have the function called Roll()? Is a underscore fine? After all, there is only one function, and it removes the need to look up the name of the class. Any thoughts?

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  • Random record in ActiveRecord

    - by astrofoo
    I'm in need of getting a random record from a table via ActiveRecord. I've followed the example from Jamis Buck from 2006. However, I've also come across another way via a Google search (can't attribute with a link due to new user restrictions): rand_id = rand(Model.count) rand_record = Model.first(:conditions => [ "id >= ?", rand_id]) I'm curious how others on here have done it or if anyone knows what way would be more efficient.

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  • Freebase; select a random record?

    - by user168083
    1) Is there any way to select a random record from Freebase? If I do a limit of 1, it consistently returns the same record. I could grab the larger data set and select a random rec from that but that seems like overkill. Analogous to MySQL's : select * from profiles order by rand() limit 1; 2) Is there any way to tell Freebase not to select certain items in a set? Analogous to MySQL's : select * from profiles where id NOT IN (SELECT profile_id from approved_profiles) Thanks in advance

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  • MYSQL JOIN SELECT Statment - omit duplicated

    - by mouthpiec
    Hi, I am tying to join the following 2 queries but I am having duplicated .... it is possible to remove duplacted fro this: ( SELECT bar_id, bar_name, town_name, bar_telephone, (subscription_type_id *2) AS subscription_type_id FROM bar, sportactivitybar, towns, subscriptiontype WHERE sport_activity_id_fk =14 AND bar_id = bar_id_fk AND town_id = town_id_fk AND subscription_type_id = subscription_type_id_fk ) UNION ( SELECT bar_id, bar_name, town_name, bar_telephone, subscription_type_id FROM bar, towns, subscriptiontype WHERE town_id = town_id_fk AND subscription_type_id = subscription_type_id_fk ) ORDER BY subscription_type_id DESC , RAND( ) Please note that I need to omit those duplicates that will have a lower subscription_type_id

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  • Rails 2.3: How to create this SQL into a named_scope

    - by randombits
    Having a bit of difficulty figuring out how to create a named_scope from this SQL query: select * from foo where id NOT IN (select foo_id from bar) AND foo.category = ? ORDER BY RAND() LIMIT 1; Category should be variable to change. What's the most efficient way the named_scope can be written for the problem above?

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  • Any special assertion to test if the resulting integer lies within a range

    - by barerd
    I would like to test if an instance variable lies in a range of numbers. I solved the problem by using assert_in_delta but would like to know if there is a formal assertion for this. #part of the tested class def initialize(value = 70 + rand(30)) @value = value end #test_value.rb class ValueTestCase < Test::Unit::TestCase def test_if_value_in_range assert_in_delta(85, p.value, 15) end end

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  • initializing a vector of custom class in c++

    - by Flamewires
    Hey basically Im trying to store a "solution" and create a vector of these. The problem I'm having is with initialization. Heres my class for reference class Solution { private: // boost::thread m_Thread; int itt_found; int dim; pfn_fitness f; double value; std::vector<double> x; public: Solution(size_t size, int funcNo) : itt_found(0), x(size, 0.0), value(0.0), dim(30), f(Eval_Functions[funcNo]) { for (int i = 1; i < (int) size; i++) { x[i] = ((double)rand()/((double)RAND_MAX))*maxs[funcNo]; } } Solution() : itt_found(0), x(31, 0.0), value(0.0), dim(30), f(Eval_Functions[1]) { for (int i = 1; i < 31; i++) { x[i] = ((double)rand()/((double)RAND_MAX))*maxs[1]; } } Solution operator= (Solution S) { x = S.GetX(); itt_found = S.GetIttFound(); dim = S.GetDim(); f = S.GetFunc(); value = S.GetValue(); return *this; } void start() { value = f (dim, x); } /* plus additional getter/setter methods*/ } Solution S(30, 1) or Solution(2, 5) work and initalizes everything, but I need X of these solution objects. std::vector<Solution> Parents(X) will create X solutions with the default constructor and i want to construct using the (int, int) constructor. Is there any easy(one liner?) way to do this? Or would i have to do something like: size_t numparents = 10; vector<Solution> Parents; Parents.reserve(numparents); for (int i = 0; i<(int)numparents; i++) { Solution S(31, 0); Parents.push_back(S); }

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  • how to use summation in matlab???

    - by lucky
    i have a randomly generated vector say A of length M say A=rand(M,1) and also i have function X(k)=sin(2*pi*k) how would i find Y(k) which is summation of A(l)*X(k-l) as l goes from 0 to M ... assume any value of k... but answer should be summation of all M+1 terms

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  • Where do you extend classes in your rails application?

    - by ro
    Just about to extend the Array class with the following extension: class Array def shuffle! size.downto(1) { |n| push delete_at(rand(n)) } self end end However, I was wondering where a good place to keep these sort of extensions. I was thinking environment.rb or putting in its own file in the initializers directory.

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  • Check if Ruby object is a Boolean

    - by viatropos
    Can't seem to find how to check if an object is a boolean easily. Is there something like this in Ruby? true.is_a?(Boolean) false.is_a?(Boolean) Right now I'm doing this and would like to shorten it: some_var = rand(1) == 1 ? true : false (some_var.is_a?(TrueClass) || some_var.is_a?(FalseClass))

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  • using markers instead of if and else statement in php

    - by Mac Taylor
    hey guys i need to shorten or better to say ., harden my codes this is my original code : if ($type = "recent") { $OrderType = "sid DESC"; }elseif ($type = "pop"){ $OrderType = "counter DESC"; }else { $OrderType = "RAND()"; } now how can i use markers like this : $OrderType = ($type = "recent") ? "sid DESC" : "counter DESC" ; i tried but i didnt know how to write elseif in marker way

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  • random number in VC++

    - by BillDickson
    int randomNumber = (double)rand() / (RAND_MAX + 1) * (10 - 0) + 0; is the code I'm using, it is getting a random number, but is getting the SAME random combination every time? Can anyone see what I'm doing wrong?

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  • c++ multithread array

    - by user1731972
    i'm doing something for fun, trying to learn multithreading Problems passing array by reference to threads but Arno pointed out that my threading via process.h wasn't going to be multi-threaded. What I'm hoping to do is something where I have an array of 100 (or 10,000, doesn't really matter I don't think), and split up the assignment of values to each thread. Example, 4 threads = 250 values per thread to be assigned. Then I can use this filled array for further calculations. Here's some code I was working on (which doesn't work) #include <process.h> #include <windows.h> #include <iostream> #include <fstream> #include <time.h> //#include <thread> using namespace std; void myThread (void *dummy ); CRITICAL_SECTION cs1,cs2; // global int main() { ofstream myfile; myfile.open ("coinToss.csv"); int rNum; long numRuns; long count = 0; int divisor = 1; float holder = 0; int counter = 0; float percent = 0.0; HANDLE hThread[1000]; int array[10000]; srand ( time(NULL) ); printf ("Runs (use multiple of 10)? "); cin >> numRuns; for (int i = 0; i < numRuns; i++) { //_beginthread( myThread, 0, (void *) (array1) ); //??? //hThread[i * 2] = _beginthread( myThread, 0, (void *) (array1) ); hThread[i*2] = _beginthread( myThread, 0, (void *) (array) ); } //WaitForMultipleObjects(numRuns * 2, hThread, TRUE, INFINITE); WaitForMultipleObjects(numRuns, hThread, TRUE, INFINITE); } void myThread (void *param ) { //thanks goes to stockoverflow //http://stackoverflow.com/questions/12801862/problems-passing-array-by-reference-to-threads int *i = (int *)param; for (int x = 0; x < 1000000; x++) { //param[x] = rand() % 2 + 1; i[x] = rand() % 2 + 1; } } Can anyone explain why it isn't working?

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  • Initializing a C++ vector to random values... fast

    - by Flamewires
    Hey, id like to make this as fast as possible because it gets called A LOT in a program i'm writing, so is there any faster way to initialize a C++ vector to random values than: double range;//set to the range of a particular function i want to evaluate. std::vector<double> x(30, 0.0); for (int i=0;i<x.size();i++) { x.at(i) = (rand()/(double)RAND_MAX)*range; } EDIT:Fixed x's initializer.

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  • SQL query, select from 2 tables random

    - by klaus
    Hello all i have a problem that i just CANT get to work like i what it.. i want to show news and reviews (2 tables) and i want to have random output and not the same output here is my query i really hope some one can explain me what i do wrong SELECT anmeldelser.billed_sti , anmeldelser.overskrift , anmeldelser.indhold , anmeldelser.id , anmeldelser.godkendt FROM anmeldelser LIMIT 0,6 UNION ALL SELECT nyheder.id , nyheder.billed_sti , nyheder.overskrift , nyheder.indhold , nyheder.godkendt FROM nyheder ORDER BY rand() LIMIT 0,6

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  • Code to generate random numbers in C++

    - by user1678927
    Basically I have to write a program to generate random numbers to simulate the rolling of a pair of dice. This program should be constructed in multiple files. The main function should be in one file, the other functions should be in a second source file, and their prototypes should be in a header file. First I write a short function that returns a random value between 1 and 6 to simulate the rolling of a single 6-sided die.Second, i write a function that pretends to roll a pair of dice by calling this function twice. My program starts by asking the user how many rolls should be made. Then I write a function to simulate rolling the dice this many times, keeping a count of exactly how many times the values 2,3,4,5,6,7,8,9,10,11,12(each number is the sum of a pair of dice) occur in an array. Later I write a function to display a small bar chart using these counts that ideally would look something like below for a sample of 144 rolls, where the number of asterisks printed corresponds to the count: 2 3 4 5 6 7 8 9 10 11 12 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Next, to see how well the random number generator is doing, I write a function to compute the average value rolled. Compare this to the ideal average of 7. Also, print out a small table showing the counts of each roll made by the program, the ideal count based on the frequencies above given the total number of rolls, and the difference between these values in separate columns. This is my incomplete code so far: "Compiler visual studio 2010" int rolling(){ //Function that returns a random value between 1 and 6 rand(unsigned(time(NULL))); int dice = 1 + (rand() %6); return dice; } int roll_dice(int num1,int num2){ //it calls 'rolling function' twice int result1,result2; num1 = rolling(); num2 = rolling(); result1 = num1; result2 = num2; return result1,result2; } int main(void){ int times,i,sum,n1,n2; int c1,c2,c3,c4,c5,c6,c7,c8,c9,c10,c11;//counters for each sum printf("Please enter how many times you want to roll the dice.\n") scanf_s("%i",&times); I pretend to use counters to count each sum and store the number(the count) in an array. I know i need a loop (for) and some conditional statements (if) but m main problem is to get the values from roll_dice and store them in n1 and n2 so then i can sum them up and store the sum in 'sum'.

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  • Counting number of searches

    - by shinjuo
    I am trying to figure out how to get the total number of tests each search makes in this algorithm. I am not sure how I can pass that information back from this algorithm though. I need to count how many times while runs and then pass that number back into an array to be added together and determine the average number of test. main.c #include <stdio.h> #include <stdlib.h> #include <time.h> #include <stdbool.h> #include "percentage.h" #include "sequentialSearch.h" #define searchAmount 100 int main(int argc, char *argv[]) { int numbers[100]; int searches[searchAmount]; int i; int where; int searchSuccess; int searchUnsuccess; int percent; srand(time(NULL)); for (i = 0; i < 100; i++){ numbers[i] = rand() % 200; } for (i = 0; i < searchAmount; i++){ searches[i] = rand() % 200; } searchUnsuccess = 0; searchSuccess = 0; for(i = 0; i < searchAmount; i++){ if(seqSearch(numbers, 100, searches[i], &where)){ searchSuccess++; }else{ searchUnsuccess++; } } percent = percentRate(searchSuccess, searchAmount); printf("Total number of searches: %d\n", searchAmount); printf("Total successful searches: %d\n", searchSuccess); printf("Success Rate: %d%%\n", percent); system("PAUSE"); return 0; } sequentialSearch.h bool seqSearch (int list[], int last, int target, int* locn){ int looker; looker = 0; while(looker < last && target != list[looker]){ looker++; } *locn = looker; return(target == list[looker]); }

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  • How do I select a random record efficiently in MySQL?

    - by user198729
    mysql> EXPLAIN SELECT * FROM urls ORDER BY RAND() LIMIT 1; +----+-------------+-------+------+---------------+------+---------+------+-------+---------------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+-------+------+---------------+------+---------+------+-------+---------------------------------+ | 1 | SIMPLE | urls | ALL | NULL | NULL | NULL | NULL | 62228 | Using temporary; Using filesort | +----+-------------+-------+------+---------------+------+---------+------+-------+---------------------------------+ The above doesn't qualify as efficient,how should I do it properly?

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