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  • Random Int in VB.Net

    - by brendan
    I need to generate random integer between 1-n (where n is a positive whole number) to use for a unit test. I don't need something overly complicated to ensure true randomnesses - just an old fashioned random number. How would I do that?

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  • how to record mic input and pipe the output to another program

    - by acrs
    Hi everyone Im trying to follow a tutorial on generating truly random bits How To Generate Truly Random Bits This is the command from the tutorial but it does not work rec -c 1 -d /dev/dsp -r 8000 -t wav -s w - | ./noise-filter >bits I know i can record my mic input using rec -c 1 no.wav this is the command i tried using rec -c 1 -r 8000 -t wav -s noise.wav | ./noise-filter >bits but i get root@xxc:~/cc# rec -c 1 -r 8000 -t wav -s noise.wav - | ./noise-filter >bits rec WARN formats: can't set sample rate 8000; using 48000 rec FAIL sox: Input files must have the same sample-rate I have complied noise-filter noise-filter I think the tutorial is using an older version of SOX and REC I'm using sox: SoX v14.3.2 on Ubuntu 12.04 server Can someone please help me ?

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  • Unreliable resume from suspend?

    - by dsimcha
    My desktop PC (home-built) resumes from suspend somewhat unreliably. I'd say that it resumes successfully about 85-90% of the time and hangs with a blank screen 5-10% of the time. As far as I can tell, the success or failure of the resume is completely random. I doubt it's a software problem because I triple boot Windows 7, Windows XP and Ubuntu and it's similar under all 3 operating systems. If it matters, my system is overclocked, though other than the resume-from-suspend issue, it's definitely rock stable. What are some of the obvious suspects that would cause random, sporadic failures to resume from suspend?

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  • New Computer freezing up at random

    - by Benjamin Frost
    Since I built my system about 4 weeks ago I'v been getting random freezes, Sometimes it can happen directly after startup and sometimes it wont freeze up for 3-4 days of 24/7 running. It seems to be happening under all stress loads but mainly when the CPU is under 10% load. It doesn't give me a BSOD or anything, it simply just freezes and repeats the last sound before the freeze until I shut it down by the power button. I'v re-seated everything in the system except the CPU, Cleaned the RAM sockets and gold fittings. None of the components have been clocked above their factory settings as of yet, don't want to overclock them until I sort out these freezes. Temps are all well under the rated max temps, the highest the temps have been are below CPU: Low load: 16-21°C Full Load (100%) 40-43°C *(From HWMonitor by CPUID) GPU 1: Low Load: 25-30°C Full Load (100%): 45-50°C GPU 2: Low Load: 23-27°C Full Load (100%): 45-50°C *(GPU Temps from Catalyst Control Center) General Case temps Rear: 18-20°C Mid: 20-21°C Front (HDD/SSD Bays): 14-19°C (Case temps may be a little off as it's from the Kaze master pro fan controller) I have Un-installed EVERY driver for Motherboard, GPU & Soundcard and Re-installed twice. Windows is all up to date. To date i'v tried the following Running Memtest for 24 hrs straight, No errors Running Memtest on each individual RAM modules, No errors Reseated everything except the CPU Cleaned DIMM Sockets and Gold inputs Tested the Graphics cards 1 at a time Re-arranged all the SATA devices to run on Chipset controlled ports Re-installing all drivers OS: Win7 Professional 64bit Motherboard: ASRock X79 Extreme9 CPU: i7 3930k 3.2GHz GPU: Sapphire 7950 OC Edition V2 (2 card Crossfire) RAM: G.Skill Ripjaws Z F3-17000CL11Q-16GBZL 16GB (4x4GB) DDR3 Boot Drive: OCZ Agility 4 128GB Data Drive 1: Western Digital Black 2TB Data Drive 2: Western Digital Black 2TB Data Drive 3: Western Digital Green 3TB Power Supply: Corsair AX1200 Gold

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  • winbind failing after a semi-random amount of time

    - by The Digital Ninja
    I have winbind set up to authenticate to our AD for samba shares. This is the third such server, and the only one having any issues. It seems after a random amount of time samba shares will just stop working. Winbind processes seem to be running but restarting them seems to fix the issue for a while. Looking at the logs have been kind of hit an miss and I don't know exactly when it fails. One interesting thing is that it seems to be pulling from another domain controller that it shoudlnt. I censored out the domain name in this example. But isnt there some way to block authentication to a domain? I'm not sure if this is a symptom or a cause of the issue. [2010/10/18 08:02:10, 0] winbindd/winbindd_cache.c:initialize_winbindd_cache(2577) initialize_winbindd_cache: clearing cache and re-creating with version number 1 [2010/10/18 09:15:54, 1] libsmb/clikrb5.c:ads_krb5_mk_req(686) ads_krb5_mk_req: krb5_get_credentials failed for [email protected] (Cannot find KDC for requested realm) [2010/10/18 09:15:54, 1] libsmb/cliconnect.c:cli_session_setup_kerberos(624) cli_session_setup_kerberos: spnego_gen_negTokenTarg failed: Cannot find KDC for requested realm [2010/10/18 09:15:54, 0] lib/util_sock.c:write_data(1139) write_data: write failure. Error = Connection reset by peer [2010/10/18 09:15:54, 0] libsmb/clientgen.c:write_socket(242) write_socket: Error writing 108 bytes to socket 18: ERRNO = Connection reset by peer [2010/10/18 09:15:54, 0] libsmb/clientgen.c:cli_send_smb(290) Error writing 108 bytes to client. -1 (Connection reset by peer)

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  • Random Excel bug when referencing a different sheet

    - by Matteo
    I am getting a very strange error anytime I try to use a formula pointing to a cell in a different sheet from the active one (even as simple as "=Sheet2!A1"). This started happening all of a sudden, and without any change in the system - only I seem to having started having the problem since I started using a workbook from another colleague with the same issue. I'm running Excel 2003 SP3 on XP. With little variants, whenever I reference a cell in a different sheet, from any formula, and then press Enter, the formula gets written on a different cell from the one I was editing it in, and throws a REF error. Example: I start editing in cell A1 of Sheet 1, type "=", then move the cursor to cell B2 of Sheet 2 (that may contain any value), and press Enter. At this stage you would expect cell A1 in Sheet 1 to contain formula "=Sheet2!B2" and display the value in that cell. Instead what happens is that the cell remains empty, and another random cell of Sheet 1 gets populated with something like "=Sheet2!#REF!" throwing an error. Interestingly, the error does not happen when I manually type the cell reference in (ie. without moving the cursor to the second sheet). Hope this is making any sense - any ideas are welcome! Thanks.

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  • Random server lag, no CPU/mem/pagefile usage

    - by Kev
    We have a fairly new server running Windows 2003 SP2, and the past few days we've noticed random slowdowns. When I'm logged into the server over remote desktop while this is happening, or if I'm physically sitting at the server logged in, suddenly everything becomes extremely laggy. Any UI element I try to interact with takes upwards of ten seconds to react, and then responds very slowly. Then a minute later everything is quite snappy again. During this, I have Task Manager minimized to the tray, and there's no CPU usage. I open it up right after this happens, and there's very little CPU usage on the graph, and no memory or pagefile usage above normal. (Normal being 1.5 GB free in the case of memory.) This is what I see logged into the server, and then users start calling saying things are slow, timing out, and failing--anything to do with our server. No events in the Event Viewer around the times this happens. The context I'm working in (last thing I clicked, etc.) seems different every time--different programs active, different combinations of programs open. Never anything particularly stressful (like adding an event entry to a Cobian Backup configuration, or editing text in TextPad, which has been exceptionally stable in my extensive usage of it.) I would've thought it was just the server, but a family member's home PC (entirely separate) running WinXPSP3 had the same thing happen to it last night a few times. Is this some new behaviour introduced by the latest Windows Updates? Either way, where do I even start to look when nothing seems to be chewing up resources?

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  • Show random string.

    - by zaid
    i am trying to display a random string each time a button is pressed from a set of strings defined in strings.xml . this is an example of the strings ID's <string name="q0"> <string name="q1"> <string name="q2"> <string name="q3"> <string name="q4"> java code for getting a random string. private static final Random rgenerator = null; int RandomQ = R.string.q0 (rgenerator.nextInt(5) + 1); String q = getString(RandomQ); if i try to use this java code i get an error at "q0" in R.string.q0 which is The method q0(int) is undefined for the type R.string if i try to use the quick fix and create a method, it works. but it wont let me save or run the app because it replaces my create method and shows this message R.java was modified manually! Reverting to generated version! thanks for reading.

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  • Gathering entropy in web apps to create (more) secure random numbers

    - by H M
    after several days of research and discussion i came up with this method to gather entropy from visitors (u can see the history of my research here) when a user visits i run this code: $entropy=sha1(microtime().$pepper.$_SERVER['REMOTE_ADDR'].$_SERVER['REMOTE_PORT']. $_SERVER['HTTP_USER_AGENT'].serialize($_POST).serialize($_GET).serialize($_COOKIE)); note: pepper is a per site/setup random string set by hand. then i execute the following (My)SQL query: $query="update `crypto` set `value`=sha1(concat(`value`, '$entropy')) where name='entropy'"; that means we combine the entropy of the visitor's request with the others' gathered already. that's all. then when we want to generate random numbers we combine the gathered entropy with the output: $query="select `value` from `crypto` where `name`='entropy'"; //... extract(unpack('Nrandom', pack('H*', sha1(mt_rand(0, 0x7FFFFFFF).$entropy.microtime())))); note: the last line is a part of a modified version of the crypt_rand function of the phpseclib. please tell me your opinion about the scheme and other ideas/info regarding entropy gathering/random number generation. ps: i know about randomness sources like /dev/urandom. this system is just an auxiliary system or (when we don't have (access to) these sources) a fallback scheme.

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  • R Random Data Sets within loops

    - by jugossery
    Here is what I want to do: I have a time series data frame with let us say 100 time-series of length 600 - each in one column of the data frame. I want to pick up 4 of the time-series randomly and then assign them random weights that sum up to one (ie 0.1, 0.5, 0.3, 0.1). Using those I want to compute the mean of the sum of the 4 weighted time series variables (e.g. convex combination). I want to do this let us say 100k times and store each result in the form ts1.name, ts2.name, ts3.name, ts4.name, weight1, weight2, weight3, weight4, mean so that I get a 9*100k df. I tried some things already but R is very bad with loops and I know vector oriented solutions are better because of R design. Thanks Here is what I did and I know it is horrible The df is in the form v1,v2,v2.....v100 1,5,6,.......9 2,4,6,.......10 3,5,8,.......6 2,2,8,.......2 etc e=NULL for (x in 1:100000) { s=sample(1:100,4)#pick 4 variables randomly a=sample(seq(0,1,0.01),1) b=sample(seq(0,1-a,0.01),1) c=sample(seq(0,(1-a-b),0.01),1) d=1-a-b-c e=c(a,b,c,d)#4 random weights average=mean(timeseries.df[,s]%*%t(e)) e=rbind(e,s,average)#in the end i get the 9*100k df } The procedure runs way to slow. EDIT: Thanks for the help i had,i am not used to think R and i am not very used to translate every problem into a matrix algebra equation which is what you need in R. Then the problem becomes a little bit complex if i want to calculate the standard deviation. i need the covariance matrix and i am not sure i can if/how i can pick random elements for each sample from the original timeseries.df covariance matrix then compute the sample variance (t(sampleweights)%*%sample_cov.mat%*%sampleweights) to get in the end the ts.weighted_standard_dev matrix Last question what is the best way to proceed if i want to bootstrap the original df x times and then apply the same computations to test the robustness of my datas thanks

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  • Objective C : UIButton image with NSArray in a random order

    - by Sarah
    Brief Idea about the flow : I have say minimum 1 and maximum 18 records in my database with a text and an image from which I have to fetch images and place any 3 of the same randomly to 3 UIButtons among which one image should match with my question. i.e. 1 is the answer and other 2 are the distractors. For Example : Question is : where is Apple? Now among the bunch of images, I want to place any 3 images on the 3 UIButtons(1 answer i.e. An Apple and 2 distractors) in a random order and on selecting the UIButton it should prompt me if it's a right answer or not. I am implementing below code for placing the UIImages in a random order : -(void) placeImages { NSMutableArray *images = [NSMutableArray arrayWithArray:arrImg]; NSArray *buttons = [NSArray arrayWithObjects:btn1,btn2,btn3, nil]; for (UIButton *btn in buttons) { int randomIndex= random() % images.count; UIImage *img = [images objectAtIndex:randomIndex]; [btn setImage:img forState:UIControlStateNormal]; [images removeObjectAtIndex:randomIndex]; } } But I am stuck at a point that how should I get 1 UIButton image with an answer and other as distractors also that how should i maintain the index of the image from the NSArray? Kindly guide me. Thank you.

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  • Are random packets normal?

    - by TheLQ
    About a month ago on one of my servers I started receiving random packets from IPs all over the world. So I did the smart thing and stopped putting off installing an IDS. This IDS is a ClearOS Gateway which comes with Snort and SnortSam. I enabled it, checked There is a total of 4 ports open, two of which forward to the server I'm talking about. These ports are 3724 and 8085, so they aren't going to be easily detected in a port scan. However checking some logs of this server I found that the attack is resuming. I found this ... Accepting connection from '75.166.155.122' [Auth] got unknown packet from '75.166.155.122' Accepting connection from '98.164.154.93' [Auth] got unknown packet from '98.164.154.93' Ping MySQL to keep connection alive Accepting connection from '70.241.195.129' [Auth] got unknown packet from '70.241.195.129' Accepting connection from '67.182.229.169' [Auth] got unknown packet from '67.182.229.169' Accepting connection from '69.137.140.38' [Auth] got unknown packet from '69.137.140.38' Accepting connection from '76.31.72.55' [Auth] got unknown packet from '76.31.72.55' Accepting connection from '97.88.139.39' [Auth] got unknown packet from '97.88.139.39' Accepting connection from '173.35.62.112' [Auth] got unknown packet from '173.35.62.112' Accepting connection from '187.15.10.73' [Auth] got unknown packet from '187.15.10.73' Accepting connection from '66.66.94.124' [Auth] got unknown packet from '66.66.94.124' Accepting connection from '75.159.219.124' [Auth] got unknown packet from '75.159.219.124' Accepting connection from '99.102.100.82' [Auth] got unknown packet from '99.102.100.82' Accepting connection from '24.128.240.45' [Auth] got unknown packet from '24.128.240.45' Accepting connection from '99.231.7.39' [Auth] got unknown packet from '99.231.7.39' Accepting connection from '206.255.79.56' [Auth] got unknown packet from '206.255.79.56' Accepting connection from '68.97.106.235' [Auth] got unknown packet from '68.97.106.235' Accepting connection from '69.134.67.251' [Auth] got unknown packet from '69.134.67.251' Accepting connection from '63.228.138.186' [Auth] got unknown packet from '63.228.138.186' Accepting connection from '184.39.146.193' [Auth] got unknown packet from '184.39.146.193' Accepting connection from '69.171.161.102' [Auth] got unknown packet from '69.171.161.102' Accepting connection from '76.0.47.228' [Auth] got unknown packet from '76.0.47.228' Ping MySQL to keep connection alive Accepting connection from '126.112.201.14' [Auth] got unknown packet from '126.112.201.14' Ping MySQL to keep connection alive Now that scares me. Why isn't Snort detecting this? How were they able to find this specific port? More importantly, what normally would these packets contain? Is this something I should be worried about? How can I stop this?

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  • How to store data on a machine whose power gets cut at random

    - by Sevas
    I have a virtual machine (Debian) running on a physical machine host. The virtual machine acts as a buffer for data that it frequently receives over the local network (the period for this data is 0.5s, so a fairly high throughput). Any data received is stored on the virtual machine and repeatedly forwarded to an external server over UDP. Once the external server acknowledges (over UDP) that it has received a data packet, the original data is deleted from the virtual machine and not sent to the external server again. The internet connection that connects the VM and the external server is unreliable, meaning it could be down for days at a time. The physical machine that hosts the VM gets its power cut several times per day at random. There is no way to tell when this is about to happen and it is not possible to add a UPS, a battery, or a similar solution to the system. Originally, the data was stored on a file-based HSQLDB database on the virtual machine. However, the frequent power cuts eventually cause the database script file to become corrupted (not at the file system level, i.e. it is readable, but HSQLDB can't make sense of it), which leads to my question: How should data be stored in an environment where power cuts can and do happen frequently? One option I can think of is using flat files, saving each packet of data as a file on the file system. This way if a file is corrupted due to loss of power, it can be ignored and the rest of the data remains intact. This poses a few issues however, mainly related to the amount of data likely being stored on the virtual machine. At 0.5s between each piece of data, 1,728,000 files will be generated in 10 days. This at least means using a file system with an increased number of inodes to store this data (the current file system setup ran out of inodes at ~250,000 messages and 30% disk space used). Also, it is hard (not impossible) to manage. Are there any other options? Are there database engines that run on Debian that would not get corrupted by power cuts? Also, what file system should be used for this? ext3 is what is used at the moment. The software that runs on the virtual machine is written using Java 6, so hopefully the solution would not be incompatible.

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  • Ubuntu server random hangups.

    - by Ebbe
    Hello all. this is my first post to this forum which I found through the superb podcast "It Conversations" from StackOverFlow. I am quite in my role as server administrator for an exhibition center in London. Basically we have a central file and sql server to which roughly 40 stations connects to to upload/download data used/captured by a set of applications. Over the last weeks we have experienced a few random hangups to our applications, and as it always happen to multiple applications simultaneously I do not believe that the applications are the source of the problem. We also monitor the network using Dartware Intermapper which indicates that all switches and stations on the network has been reachable during the downtime. Thus, its all pointing to the server. I have been looking through all log files I can think of and the only thing so far that I have found suspicious is the following lines in the syslog which are from the time of one of the hangups: Feb 6 17:14:27 es named[5582]: client 127.0.0.1#33721: RFC 1918 response from Internet for 150.0.168.192.in-addr.arpa Feb 6 17:14:40 es named[5582]: client 127.0.0.1#32899: RFC 1918 response from Internet for 152.0.168.192.in-addr.arpa Feb 6 17:15:01 es /USR/SBIN/CRON[1956]: (es) CMD (/home/es/apps/es/bin/es_checksum.sh) Feb 6 17:16:06 es /USR/SBIN/CRON[2031]: (es) CMD (/home/es/apps/es/bin/es_checksum.sh) Feb 6 17:21:00 es named[5582]: *** POKED TIMER *** Feb 6 17:21:00 es last message repeated 2 times Feb 6 17:21:07 es named[5582]: client 127.0.0.1#44194: RFC 1918 response from Internet for 143.0.168.192.in-addr.arpa Feb 6 17:21:12 es named[5582]: client 127.0.0.1#59004: RFC 1918 response from Internet for 164.0.168.192.in-addr.arpa I find a few lines of interesting lines here: 1) "RFC 1918 response from Internet for 150.1.168.192.in-addr.arpa". I see this a lot in the syslog. And basically everytime I do a nslookup for any of the computers in the cluster I get a new similar line in the syslog. I understand from google that this has to do with reverse lookup problems. But I do not know how that could effect the systems. Lets say that one of these lines appear every time one of the userstations connects to the server, which may happen several times a second. Could this possible cause a hangup of the entire server? 2) POKED TIMER, I have googled this quite a lot, but not found an explaination that I can relate to. What does this mean? 3) The timestamps, it seems like the entire server has stopped responding for several minutes. Normally there are many printouts to the syslog per minute on this server. Furthermore the CRON job is set to run once every minute. Which according to the log, hasent happened here. OS: Ubuntu 8.04 Kernel: Linux 2.6.24-24-server x86_64 GNU/Linux. Hardware: Dell R710, RAID1, CPU: 2x XEON E5530. 16GB Memory. Average load is very low, and memory should not be a problem. Please let me know if you need any additional information. Best wishes, Ebbe

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  • Distinct rand() sequences yielding the same results in an expression

    - by suszterpatt
    Ok, this is a really weird one. I have an MPI program, where each process has to generate random numbers in a fixed range (the range is read from file). What happens is that even though I seed each process with a different value, and the numbers generated by rand() are different in each process, the expression to generate the random numbers still yields the same sequence between them. Here's all relevant code: // 'rank' will be unique for each process int rank; MPI_Comm_rank(MPI_COMM_WORLD, &rank); // seed the RNG with a different value for each process srand(time(NULL) + rank); // print some random numbers to see if we get a unique sequence in each process // 'log' is a uniquely named file, each process has its own log << rand() << " " << rand() << " " << rand() << std::endl; // do boring deterministic stuff while (true) { // waitTimeMin and waitTimeMax are integers, Max is always greater than Min waitSecs = waitTimeMin + rand() % (waitTimeMax - waitTimeMin); log << "waiting " << waitSecs << " seconds" << std::endl; sleep(waitSecs); // do more boring deterministic stuff } Here's the output of each process, with 3 processes generating numbers in the range [1,9]. process 1: 15190 28284 3149 waiting 6 seconds waiting 8 seconds waiting 9 seconds waiting 4 seconds process 2: 286 6264 3153 waiting 6 seconds waiting 8 seconds waiting 9 seconds waiting 4 seconds process 3: 18151 17013 3156 waiting 6 seconds waiting 8 seconds waiting 9 seconds waiting 4 seconds So while rand() clearly generates different numbers, the expression to calculate waitSecs still evaluates to the same sequence on all processes. What's even weirder: if I run the program with the same parameteres again, only the first 3 random numbers will change, the rest of the "random" sequence will be exactly the same in each run! Changing the range of numbers will obviously produce a different result from this one, but the same parameters always yield the same sequence, between processes and between executions: except for the first 3 numbers. Just what the hell is going on here?

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  • Randomised objects are assigning themselves to more than one array location

    - by Thaddeus Aid
    this.size = 9; this.populationSize = 10; Random rand = new Random(); Integer[][] easy1 = new Integer[size][size]; easy1 = this.initializeEasy1(easy1); this.sudokuArray = new Sudoku[this.populationSize]; for (int i = 0; i < this.sudokuArray.length; i++){ long seed = rand.nextLong(); System.out.println("" + seed); this.sudokuArray[i] = new Sudoku(easy1, this.size, seed); } I am building an evolutionary sudoku solver and I am having a problem where the last Sudoku object is overwriting all the other objects in the array. Where in the code did I mess up? /edit here is the constructor of the class public Sudoku(Integer[][] givensGrid, int s, long seed){ this.size = s; this.givens = givensGrid; this.grid = this.givens.clone(); Random rand = new Random(seed); System.out.println("Random " + rand.nextInt()); // step though each row of the grid for (int i = 0; i < size; i++){ ArrayList<Integer> numbers = new ArrayList<Integer>(); numbers = this.makeNumbers(numbers); // step through each column to find the givens and remove from numbers for (int j = 0; j < size; j++){ if (this.grid[i][j] != 0){ numbers.remove(this.grid[i][j]); } } // go back through the row and assign the numbers randomly for (int j = 0; j < size; j++){ if (this.grid[i][j] == 0){ int r = rand.nextInt(numbers.size()); this.grid[i][j] = numbers.get(r); numbers.remove(r); } } } System.out.println("============="); System.out.println(this.toString()); }

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  • rand() generating the same number – even with srand(time(NULL)) in my main!

    - by Nick Sweet
    So, I'm trying to create a random vector (think geometry, not an expandable array), and every time I call my random vector function I get the same x value, thought y and z are different. int main () { srand ( (unsigned)time(NULL)); Vector<double> a; a.randvec(); cout << a << endl; return 0; } using the function //random Vector template <class T> void Vector<T>::randvec() { const int min=-10, max=10; int randx, randy, randz; const int bucket_size = RAND_MAX/(max-min); do randx = (rand()/bucket_size)+min; while (randx <= min && randx >= max); x = randx; do randy = (rand()/bucket_size)+min; while (randy <= min && randy >= max); y = randy; do randz = (rand()/bucket_size)+min; while (randz <= min && randz >= max); z = randz; } For some reason, randx will consistently return 8, whereas the other numbers seem to be following the (pseudo) randomness perfectly. However, if I put the call to define, say, randy before randx, randy will always return 8. Why is my first random number always 8? Am I seeding incorrectly?

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  • [MySQL/PHP] Avoid using RAND()

    - by Andrew Ellis
    So... I have never had a need to do a random SELECT on a MySQL DB until this project I'm working on. After researching it seems the general populous says that using RAND() is a bad idea. I found an article that explains how to do another type of random select. Basically, if I want to select 5 random elements, I should do the following (I'm using the Kohana framework here)? If not, what is a better solution? Thanks, Andrew <?php final class Offers extends Model { /** * Loads a random set of offers. * * @param integer $limit * @return array */ public function random_offers($limit = 5) { // Find the highest offer_id $sql = ' SELECT MAX(offer_id) AS max_offer_id FROM offers '; $max_offer_id = DB::query(Database::SELECT, $sql) ->execute($this->_db) ->get('max_offer_id'); // Check to make sure we're not trying to load more offers // than there really is... if ($max_offer_id < $limit) { $limit = $max_offer_id; } $used = array(); $ids = ''; for ($i = 0; $i < $limit; ) { $rand = mt_rand(1, $max_offer_id); if (!isset($used[$rand])) { // Flag the ID as used $used[$rand] = TRUE; // Set the ID if ($i > 0) $ids .= ','; $ids .= $rand; ++$i; } } $sql = ' SELECT offer_id, offer_name FROM offers WHERE offer_id IN(:ids) '; $offers = DB::query(Database::SELECT, $sql) ->param(':ids', $ids) ->as_object(); ->execute($this->_db); return $offers; } }

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  • Getting a "for each" loop in Java to run in different order everytime

    - by R Stokes
    Hi, Basically my problem is that I'm trying to write a method that finds a random path in a graph of strings, which takes as it's parameters a start string, an integer length and a Vector of strings that will store the path. I'm attempting to do this by first adding the starting string to our blank vector, recursing through its neighbors until the vector's length (not including the start node) is the same as the integer length specified in the parameters. I've provided my code so far here: public Vector<String> findRandomPathFrom(String n, int len, Vector<String> randomPath){ randomPath.add(n); if (randomPath.size() == len + 1) return randomPath; for (String m : this.neighbours(n)){ if (!randomPath.contains(m) && findRandomPathFrom(m, len, randomPath) != null) return randomPath; } path.setSize(path.size() - 1); return null; } It seems to be working fine, returning a path with exactly the number of strings specified after the given start string. However, for any given starting string it generates the EXACT same path everytime, which kind of defeats the purpose of it being a random path generator. I'm guessing this problem is related to my "for each" loop, which loops through all the neighbouring strings of your current string. It seems to just be going with the first string in the neighbours vector every single time. Can anyone help me fix this problem so that it will choose a random neighbour instead of going in order? tl;dr - Any way of getting a "for each" loop in java to process a collection in a random order as oppoosed to start-to-finsih? Thanks in advance

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  • Simple POST random number issue in PHP

    - by MrEnder
    Ok I am trying to make something to ask you random multiplication questions. Now it asks the questions fine. Generates the random questions fine. But when it reloads the page the random numbers are different... how can I fix this? <?php $rndnum1 = rand(1, 12); $rndnum2 = rand(1, 12); echo "<h3>". $rndnum1 . " x "; echo $rndnum2 . "</h3>"; if($_SERVER["REQUEST_METHOD"] == "GET") { $answer=0; } else if($_SERVER["REQUEST_METHOD"] == "POST") { $answer=trim($_POST["answerInput"]); $check=$rndnum1*$rndnum2; if($answer==$check) { echo "Correct!"; } else { echo "Wrong!"; } } ?> <form action="<?php echo $_SERVER['PHP_SELF']; ?>" method="post" > <table> <tr> <td> First Name:&nbsp; </td> <td> <input type="text" name="answerInput" value="<?php echo $answer; ?>" size="20"/> </td> <td> <?php echo $answerError; ?> </td> </tr> <tr> <td class="signupTd" colspan="2"> <input type="submit" name="submit" value="Submit"/> </td> </tr> </table> </form>

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  • Random value from Flags enum

    - by Chris Porter
    Say I have a function that accepts an enum decorated with the Flags attribute. If the value of the enum is a combination of more than one of the enum elements how can I extract one of those elements at random? I have the following but it seems there must be a better way. [Flags] enum Colours { Blue = 1, Red = 2, Green = 4 } public static void Main() { var options = Colours.Blue | Colours.Red | Colours.Green; var opts = options.ToString().Split(','); var rand = new Random(); var selected = opts[rand.Next(opts.Length)].Trim(); var myEnum = Enum.Parse(typeof(Colours), selected); Console.WriteLine(myEnum); Console.ReadLine(); }

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  • Stable random color algorithm

    - by Olmo
    Here we have an interesting real-world algorithm requirement involving colors. 1) Nice random colors: In ordeeing to draw a beautifull chart (i.e: pie chart) we need to pick a random set of Colors that: a) are different enought b) Play nicely Doesnt Look hard. For example u fix bright and saturation and divide hue in steps of 360/Num_sectors 2) Stable: given Pie1 with sectors with labes ('A','B','C') and Pie2 with sector with labels ('B','C','D'), will be nice if color('B',pie1)= color('B',pie2) and the same for 'C' and so on, so people don't get crazy when seeing similar updated charts, even if some sectors appear some dissapeared or the number of sectors changed. The label is the only stable thing. 3) hard-coded colors: the algorithm allows hardcoded label-color relationships as an input but stills doing a good work (1 & 2) for the rest of free labels. I think this algorithm, even if it looks quite ad-hoc, will be usefull in more then one situation. Any ideas?

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