Search Results

Search found 6493 results on 260 pages for 'random generator'.

Page 17/260 | < Previous Page | 13 14 15 16 17 18 19 20 21 22 23 24  | Next Page >

  • Looking for a clear and concise web page explaining why lower bits of random numbers are usually not

    - by Hamish Grubijan
    I am putting together an internal "every developer should know" wiki page. I saw many discussions regarding rand() % N, but not a single web page that explains it all. For instance, I am curious if this problem is only C- and Linux-specific, or if it also applies to Windows, C++,. Java, .Net, Python, Perl. Please help me get to the bottom of this. Also, just how non-random do the numbers get? Thank you!

    Read the article

  • MySQL Query to receive random combinations from two tables.

    - by Michael
    Alright, here is my issue, I have two tables, one named firstnames and the other named lastnames. What I am trying to do here is to find 100 of the possible combinations from these names for test data. The firstnames table has 5494 entries in a single column, and the lastnames table has 88799 entries in a single column. The only query that I have been able to come up with that has some results is: select * from (select * from firstnames order by rand()) f LEFT JOIN (select * from lastnames order by rand()) l on 1=1 limit 10; The problem with this code is that it selects 1 firstname and gives every lastname that could go with it. While this is plausible, I will have to set the limit to 500000000 in order to get all the combinations possible without having only 20 first names(and I'd rather not kill my server). However, I only need 100 random generations of entries for test data, and I will not be able to get that with this code. Can anyone please give me any advice?

    Read the article

  • PHP rand function (or not so rand)

    - by Badr Hari
    I was testing PHP rand function to write on a image. Of course the output shows that it's not so random. The code I used: <?php header('Content-Type: image/png'); $lenght = 512; $im = imagecreatetruecolor($lenght, $lenght); $blue = imagecolorallocate($im, 0, 255, 255); for ($y = 0; $y < $lenght; $y++) { for ($x = 0; $x < $lenght; $x++) { if (rand(0,1) == 0) { imagesetpixel($im, $x, $y, $blue); } } } imagepng($im); imagedestroy($im); ?> My question is, if I use image width/lenght (variable $lenght in this example) number like 512, 256 or 1024, it is very clear that it's not so random. When I change the variable to 513 for an example, it is so much harder for human eye to detect it. Why is that? What is so special about these numbers? 512: 513: Edit: I'm running xampp on Windows to test it.

    Read the article

  • Using a permutation table for simplex noise without storing it

    - by J. C. Leitão
    Generating Simplex noise requires a permutation table for randomisation (e.g. see this question or this example). In some applications, we need to persist the state of the permutation table. This can be done by creating the table, e.g. using def permutation_table(seed): table_size = 2**10 # arbitrary for this question l = range(1, table_size + 1) random.seed(seed) # ensures the same shuffle for a given seed random.shuffle(l) return l + l # see shared link why l + l; is a detail and storing it. Can we avoid storing the full table by generating the required elements every time they are required? Specifically, currently I store the table and call it using table[i] (table is a list). Can I avoid storing it by having a function that computes the element i, e.g. get_table_element(seed, i). I'm aware that cryptography already solved this problem using block cyphers, however, I found it too complex to go deep and implement a block cypher. Does anyone knows a simple implementation of a block cypher to this problem?

    Read the article

  • How to generate a random unique string with more than 2^30 combination. I also wanted to reverse the process. Is this possible?

    - by Yusuf S
    I have a string which contains 3 elements: a 3 digit code (example: SIN, ABD, SMS, etc) a 1 digit code type (example: 1, 2, 3, etc) a 3 digit number (example: 500, 123, 345) Example string: SIN1500, ABD2123, SMS3345, etc.. I wanted to generate a UNIQUE 10 digit alphanumeric and case sensitive string (only 0-9/a-z/A-Z is allowed), with more than 2^30 (about 1 billion) unique combination per string supplied. The generated code must have a particular algorithm so that I can reverse the process. For example: public static void main(String[] args) { String test = "ABD2123"; String result = generateData(test); System.out.println(generateOutput(test)); //for example, the output of this is: 1jS8g4GDn0 System.out.println(generateOutput(result)); //the output of this will be ABD2123 (the original string supplied) } What I wanted to ask is is there any ideas/examples/libraries in java that can do this? Or at least any hint on what keyword should I put on Google? I tried googling using the keyword java checksum, rng, security, random number, etc and also tried looking at some random number solution (java SecureRandom, xorshift RNG, java.util.zip's checksum, etc) but I can't seem to find one? Thanks! EDIT: My use case for this program is to generate some kind of unique voucher number to be used by specific customers. The string supplied will contains 3 digit code for company ID, 1 digit code for voucher type, and a 3 digit number for the voucher nominal. I also tried adding 3 random alphanumeric (so the final digit is 7 + 3 digit = 10 digit). This is what I've done so far, but the result is not very good (only about 100 thousand combination): public static String in ="somerandomstrings"; public static String out="someotherrandomstrings"; public static String encrypt(String kata) throws Exception { String result=""; String ina=in; String outa=out; Random ran = new Random(); Integer modulus=in.length(); Integer offset= ((Integer.parseInt(Utils.convertDateToString(new Date(), "SS")))+ran.nextInt(60))/2%modulus; result=ina.substring(offset, offset+1); ina=ina+ina; ina=ina.substring(offset, offset+modulus); result=result+translate(kata, ina, outa); return result; } EDIT: I'm sorry I forgot to put the "translate" function : public static String translate(String kata,String seq1, String seq2){ String result=""; if(kata!=null&seq1!=null&seq2!=null){ String[] a=kata.split(""); for (int j = 1; j < a.length; j++) { String b=a[j]; String[]seq1split=seq1.split(""); String[]seq2split=seq2.split(""); int hint=seq1.indexOf(b)+1; String sq=""; if(seq1split.length>hint) sq=seq1split[hint]; String sq1=""; if(seq2split.length>hint) sq1=seq2split[hint]; b=b.replace(sq, sq1); result=result+b; } } return result; }

    Read the article

  • Why is the compiler caching my "random" and NULLED variables?

    - by alex gray
    I am confounded by the fact that even using different programs (on the same machine) to run /compile, and after nilling the vaues (before and after) the function.. that NO MATTER WHAT.. I'll keep getting the SAME "random" numbers… each and every time I run it. I swear this is NOT how it's supposed to work.. I'm going to illustrate as simply as is possible… #import <Foundation/Foundation.h> int main(int argc, char *argv[]) { int rPrimitive = 0; rPrimitive = 1 + rand() % 50; NSNumber *rObject = nil; rObject = [NSNumber numberWithInt:rand() % 10]; NSLog(@"%i %@", rPrimitive, rObject); rPrimitive = 0; rObject = nil; NSLog(@"%i %@", rPrimitive, rObject); return 0; } Run it in TextMate: i686-apple-darwin11-llvm-gcc-4.2 8 9 0 (null) Run it in CodeRunner: i686-apple-darwin11-llvm-gcc-4.2 8 9 0 (null) Run it a million times, if you'd like. You can gues what it will always be. Why does this happen? Why oh why is this "how it is"?

    Read the article

  • java.util.Random zero argument enquiry

    - by deerb
    I am trying to code a game following instructions contained in an OU TMA document which read: In the constructor, write code to assign a new instance of Random to ran which you should create using the Random class's zero argument constructor Will this code work? Random ran = new Random(0) ; I am a relative newbie to Java, and I don't understand exactly what the instructions mean

    Read the article

  • PC powers off at random times

    - by Timo Huovinen
    Short Version After experiencing some problems with Mobo batteries my PC started to power off at random times, the power off is instant and sudden and does not restart afterwards, need help figuring out the cause. Facts: Powers off when PC is playing games Powers off when PC is idle Powers off when PC is in safe mode Powers off when PC is in BIOS Powers off when PC is booted through a Windows installation USB Replaced the motherboard battery several times Replaced the 650W PSU with a 750W PSU Replaced the RAM Swapped the RAM between slots Re-applied thermal paste to the CPU Checked if the motherboard touches the case Nothing is overclocked PC Specs PC specs: OS: Windows 7 Ultimate SP1 RAM: klingston 1333MHz 4GB stick CPU: AMD Phenom II x4 955 Mobo: Gigabyte 88GMA-UD2H rev 2.2 Motherboard battery: CR2032 3v HDD: 500GB Seagate ST3500418AS ATA Device Graphics: ATI/AMD Radeon HD 6870 Very Long version Around 10 months ago I built a brand new gaming PC. Around 6 months ago it's time setting in windows started resetting to the year 2010. I swapped the Motherboard battery for a new one of the exact same size and shape and voltage, and the problems disappeared...for around 2 weeks. Then the same problem happened again, time gets reset, I swapped the battery again, and the problem was gone for good and everything was great for about 3 months.. then another problem started happening, the PC started to power off suddenly and without warning at completely random times, sometimes the PC works for and hour, sometimes 5 minutes. So I read on the forums that it might be either the PSU or the motherboard Battery or RAM or HDD or the Graphics card or the CPU or the motherboard or the drivers or a Virus or Grounding issues, or something short circuiting, basically it can be anything... I spent some days researching, and decided to remove the possibility of a virus. I reset the CMOS, cleared all BIOS settings and reinstalled windows 7 after a full format of the HDD, but the random power off kept happening. I then disabled the restart on error option in windows and looked at the event log for error events, but they did not help me figure out the problem. Network list service depends on network location awareness the dependency group failed to start Source Kernel Power Event 41 Task Category 63 Source Disk Event ID 11 Task Category None The driver detected a controller error on device disk I took apart the PC, every little piece, re-applied some expensive thermal paste to the CPU, and double checked that none of the pieces are touching the PC case. The problem was gone, the PC no longer powered off randomly I re-attached the graphics card and all was good for 4 months... then the power off problem appeared again, but was happening at high intervals, the PC would shutdown once in 2 days on average, at random points in time, sometimes when it's idle all day long, sometimes when it's running CRYSIS 2. I checked the CPU temperature, because I know that AMD CPU's have a built in protection mechanism that switches off the PC if the CPU gets too hot, and the Temp was 50C system temp, and 45C CPU after running the PC all day long (I did not do tests to see if there are any temperature spikes, don't know how to do them) Originally the PSU that powered the PC was 650Watts and had one 4 pin cable to power the CPU, I replaced it with a new 750Watts PSU which has two 4 pin cables for the CPU, but the problem remained. I removed the graphics card and let the motherboard use the built in one, but the PC kept suddenly powering off at random times. I took apart the PC completely again, and re-applied thermal paste to the CPU, added lots of insulation, and checked for any type of short-circuit possibility again and again, but the problem remained. The problem was like that for some months. I replaced the Battery a couple of times over the time, changed lots of options in windows, and tried everything I could, but it kept powering off, so I stopped using the PC as much as I used to, just living with the random power offs from time to time, until a couple of days ago, when the power off happens almost immediately after powering on the PC. I replaced the RAM with a brand new one, but that did not help. Took apart the PC again, checked for anything anywhere that might cause it, found some small scratches on the very edge of the motherboard to the left of the PCI express x16 slot. This might cause the problem, I thought, but the scratch looks very superficial, not deep at all, and if the scratch did harm the motherboard, wouldn't it cause it to not start at all? And why did it start to power off a while ago, and then suddenly stop powering off? The scratches could not have vanished??? did chkdsk \d but it powered off when it was at 75% I removed the hard disks, the graphics card, while I fiddled with the BIOS settings, and suddenly the PC shut down while I was looking at the BIOS version. This makes me realize, it is not caused by: HDD, Windows, Drivers or the Graphics card I cleared the CMOS again, updated the BIOS from F5 to F6f beta, but that did not help, it might even seem that the PC powers off even sooner. The shutdown even happened to me while I booted through a windows 7 installation USB and was in the repair console. I removed one of the cables powering the CPU, now only one 4pin cable powers it, and it worked for 30mins after doing that, which makes me think that it's the CPU overheating, and because it gets less power, it overheats slower? The things that I am still considering: CPU overheating (does not seem to overheat, maybe false readings?) Motherboard short circuiting (faulty motherboard?) I desperately need some advice in what is faulty, is it a faulty Motherboard or an overheating CPU? or maybe something else? I have been breaking my head over this problem over a span of 6 months. I'm not sure if this is a good place to ask this question, if it is not, then tell me where I can get some experienced help. More info I have also discovered a mysterious piece that seems to have fallen out of the motherboard i119.photobucket.com/albums/o126/yurikolovsky/strangepiece.jpg What is it? Looks like each time that it powers off the datetime gets reset I also found another forum post tomshardware.co.uk/forum/… except I don't have Integrated PeripheralsUSB Keyboard Function option in BIOS :S Comments summary (asked by Random moderator) Q. tell me, if the computer restarts, is it immediately? Does it take a second and then restarts? Do you see (BSOD) or hear (PSU, short circuit) any suspicious when it happens? After reading trough it, it remains the mainboard that is faulty. – JohannesM A. Immediate power off, all the fans stop instantly, all the light turn off instantly, no sound or anything, and it remains off until I turn it back on. Thanks for the feedback, faulty motherboard is what I fear. Q. Try stress-testing the system with Prime95 and see if errors or shutdowns occur when the CPU is under full load. – speakr A. Prime95 heat stress test peaked CPU heat at 60C after 5mins, it powered off after 30mins of testing in the middle of the test with no errors, Prime95 Heat test or the stress-testing with low RAM usage (small or in-place FFTs) do not report errors while testing for 10-60 mins. The power off does not seem like it is affected by Prime95 at all Makes me wonder if it's a CPU or Motherboard issue at all. Q. I had similar random/intermittent problems with my old board. It gave one of a few different symptoms: keyboard and/or mouse would die and/or the RAM wouldn't work and/or it would shut down. It was in bad shape. One problems was that my old PSU had literally burned the connector on it (browned around the pins), another was that a broken lead inside the layers of the PCB would work sometimes if it happened to be hot or if I bent the board—by jamming a hunk of wood behind it. I managed to keep the board alive for several years, but eventually nothing I did would make it work correctly anymore. – Synetech A. I will try that as the last resort, ok? ;) Q. Have you tried a different power cord, surge protector, outlet (on a different circuit). It's worth a shot just to ensure it's not subpar wiring or a week circuit (dips in power may cause shutdown if the PSU can't pull enough juice from the wall). – Kyle A. yes, I attached the PC to an entirely different outlet on a different circuit and the problem persists. After connecting it to a different outlet after starting the PC it gave me 3 long beeps and 1 short one, then the PC immediately proceeded to boot up normally. Q. Re-check your mainboard manual and all PSU connections to your mainboard to be sure that nothing is missing (e.g. 12V ATX 4-pin/6-pin connector). If you can provoke shutdowns with Prime95, then consider buying new hardware -- a stable system should run Prime95 for 24h without any errors. Prime95 mentions errors in the log when they occur and gives a summary after the stress test was stopped manually (e.g. "0 errors, 0 warnings", if all is fine) – speakr A. Re-checked, there are no more PSU connectors that I can physically connect, except the one ATX 4-pin (there are 2 that power the CPU) that I disconnected on purpose, I have reconnected it but the problem persists. Q. With one PC I had a short curcuit. The power button on the front plate had its cables soldered, but not isolated, and the contacts were very close to the metal case. A heavier touch was enough to cause a shutdown. The PC's vibration could be enough – ott-- A. yes, it seems to switch off with even the lightest touch, I switched on the PC, then pulled out the front panel power cable that connects to the motherboard so the power button does not work anymore, after 5 mins of working like that, with the power button completely disconnected, just sitting idle, the PC powered off again, I don't think it's the power button. Q. I wonder if you dare to operate components without the case, that is remove motherboard, power, disk ( just put the motherboard on a wooden desk). Don't bend the adapters when running like that. – ott-- A. yes, I do dare to do that, but only tomorrow, too tired/late right now.

    Read the article

  • selected option not clearing from memory android

    - by user2980560
    I have a small random number spinner that when you click gives a random number. I am having two problems. The first is when the main activity loads it displays a random number on the screen without the random number spinner being clicked. I am unsure what to set to false to keep it from opening with the main activity. The second problem is that when you select an option from the spinner it does not clear. Meaning that If you click on option D6 or D20 then you can not click on the same option again until selecting the other option first. Essentially the selection does not clear out of memory after the random number is selected. Here is the random number code public void onItemSelected(AdapterView<?> parent, View view, int pos, long id) { Random rand = new Random(); int roll; // An item was selected. if (spinner1.getSelectedItemPosition()==0) { roll = rand.nextInt(6)+1; } else { roll = rand.nextInt(20)+1; } // Put the result into a string. String text = "You rolled a " + roll; // Build a dialog box and with the result string and a single button AlertDialog.Builder builder = new AlertDialog.Builder(this); builder.setMessage(text).setCancelable(false) .setPositiveButton("OK", new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int id) { // do things when the user clicks ok. } }); AlertDialog alert = builder.create(); // Show the dialog box. alert.show(); }

    Read the article

  • A python random function acts differently when assigned to a list or called directly...

    - by Dror Hilman
    I have a python function that randomize a dictionary representing a position specific scoring matrix. for example: mat = { 'A' : [ 0.53, 0.66, 0.67, 0.05, 0.01, 0.86, 0.03, 0.97, 0.33, 0.41, 0.26 ] 'C' : [ 0.14, 0.04, 0.13, 0.92, 0.99, 0.04, 0.94, 0.00, 0.07, 0.23, 0.35 ] 'T' : [ 0.25, 0.07, 0.01, 0.01, 0.00, 0.04, 0.00, 0.03, 0.06, 0.12, 0.14 ] 'G' : [ 0.08, 0.23, 0.20, 0.02, 0.00, 0.06, 0.04, 0.00, 0.54, 0.24, 0.25 ] } The scambling function: def scramble_matrix(matrix, iterations): mat_len = len(matrix["A"]) pos1 = pos2 = 0 for count in range(iterations): pos1,pos2 = random.sample(range(mat_len), 2) #suffle the matrix: for nuc in matrix.keys(): matrix[nuc][pos1],matrix[nuc][pos2] = matrix[nuc][pos2],matrix[nuc][pos1] return matrix def print_matrix(matrix): for nuc in matrix.keys(): print nuc+"[", for count in matrix[nuc]: print "%.2f"%count, print "]" now to the problem... When I try to scramble a matrix directly, It's works fine: print_matrix(mat) print "" print_matrix(scramble_matrix(mat,10)) gives: A[ 0.53 0.66 0.67 0.05 0.01 0.86 0.03 0.97 0.33 0.41 0.26 ] C[ 0.14 0.04 0.13 0.92 0.99 0.04 0.94 0.00 0.07 0.23 0.35 ] T[ 0.25 0.07 0.01 0.01 0.00 0.04 0.00 0.03 0.06 0.12 0.14 ] G[ 0.08 0.23 0.20 0.02 0.00 0.06 0.04 0.00 0.54 0.24 0.25 ] A[ 0.41 0.97 0.03 0.86 0.53 0.66 0.33.05 0.67 0.26 0.01 ] C[ 0.23 0.00 0.94 0.04 0.14 0.04 0.07 0.92 0.13 0.35 0.99 ] T[ 0.12 0.03 0.00 0.04 0.25 0.07 0.06 0.01 0.01 0.14 0.00 ] G[ 0.24 0.00 0.04 0.06 0.08 0.23 0.54 0.02 0.20 0.25 0.00 ] but when I try to assign this scrambling to a list , it does not work!!! ... print_matrix(mat) s=[] for x in range(3): s.append(scramble_matrix(mat,10)) for matrix in s: print "" print_matrix(matrix) result: A[ 0.53 0.66 0.67 0.05 0.01 0.86 0.03 0.97 0.33 0.41 0.26 ] C[ 0.14 0.04 0.13 0.92 0.99 0.04 0.94 0.00 0.07 0.23 0.35 ] T[ 0.25 0.07 0.01 0.01 0.00 0.04 0.00 0.03 0.06 0.12 0.14 ] G[ 0.08 0.23 0.20 0.02 0.00 0.06 0.04 0.00 0.54 0.24 0.25 ] A[ 0.01 0.66 0.97 0.67 0.03 0.05 0.33 0.53 0.26 0.41 0.86 ] C[ 0.99 0.04 0.00 0.13 0.94 0.92 0.07 0.14 0.35 0.23 0.04 ] T[ 0.00 0.07 0.03 0.01 0.00 0.01 0.06 0.25 0.14 0.12 0.04 ] G[ 0.00 0.23 0.00 0.20 0.04 0.02 0.54 0.08 0.25 0.24 0.06 ] A[ 0.01 0.66 0.97 0.67 0.03 0.05 0.33 0.53 0.26 0.41 0.86 ] C[ 0.99 0.04 0.00 0.13 0.94 0.92 0.07 0.14 0.35 0.23 0.04 ] T[ 0.00 0.07 0.03 0.01 0.00 0.01 0.06 0.25 0.14 0.12 0.04 ] G[ 0.00 0.23 0.00 0.20 0.04 0.02 0.54 0.08 0.25 0.24 0.06 ] A[ 0.01 0.66 0.97 0.67 0.03 0.05 0.33 0.53 0.26 0.41 0.86 ] C[ 0.99 0.04 0.00 0.13 0.94 0.92 0.07 0.14 0.35 0.23 0.04 ] T[ 0.00 0.07 0.03 0.01 0.00 0.01 0.06 0.25 0.14 0.12 0.04 ] G[ 0.00 0.23 0.00 0.20 0.04 0.02 0.54 0.08 0.25 0.24 0.06 ] What is the problem??? Why the scrambling do not work after the first time, and all the list filled with the same matrix?!

    Read the article

  • How to generate and encode (for use in GA), random, strict, binary rooted trees with N leaves?

    - by Peter Simon
    First, I am an engineer, not a computer scientist, so I apologize in advance for any misuse of nomenclature and general ignorance of CS background. Here is the motivational background for my question: I am contemplating writing a genetic algorithm optimizer to aid in designing a power divider network (also called a beam forming network, or BFN for short). The BFN is intended to distribute power to each of N radiating elements in an array of antennas. The fraction of the total input power to be delivered to each radiating element has been specified. Topologically speaking, a BFN is a strictly binary, rooted tree. Each of the (N-1) interior nodes of the tree represents the input port of an unequal, binary power splitter. The N leaves of the tree are the power divider outputs. Given a particular power divider topology, one is still free to map the power divider outputs to the array inputs in an arbitrary order. There are N! such permutations of the outputs. There are several considerations in choosing the desired ordering: 1) The power ratio for each binary coupler should be within a specified range of values. 2) The ordering should be chosen to simplify the mechanical routing of the transmission lines connecting the power divider. The number of ouputs N of the BFN may range from, say, 6 to 22. I have already written a genetic algorithm optimizer that, given a particular BFN topology and desired array input power distribution, will search through the N! permutations of the BFN outputs to generate a design with compliant power ratios and good mechanical routing. I would now like to generalize my program to automatically generate and search through the space of possible BFN topologies. As I understand it, for N outputs (leaves of the binary tree), there are $C_{N-1}$ different topologies that can be constructed, where $C_N$ is the Catalan number. I would like to know how to encode an arbitrary tree having N leaves in a way that is consistent with a chromosomal description for use in a genetic algorithm. Also associated with this is the need to generate random instances for filling the initial population, and to implement crossover and mutations operators for this type of chromosome. Any suggestions will be welcome. Please minimize the amount of CS lingo in your reply, since I am not likely to be acquainted with it. Thanks in advance, Peter

    Read the article

  • How do I randomly generate a top-down 2D level with separate sections and is infinite?

    - by Bagofsheep
    I've read many other questions/answers about random level generation but most of them deal with either randomly/proceduraly generating 2D levels viewed from the side or 3D levels. What I'm trying to achieve is sort of like you were looking straight down on a Minecraft map. There is no height, but the borders of each "biome" or "section" of the map are random and varied. I already have basic code that can generate a perfectly square level with the same tileset (randomly picking segments from the tileset image), but I've encountered a major issue for wanting the level to be infinite: Beyond a certain point, the tiles' positions become negative on one or both of the axis. The code I use to only draw tiles the player can see relies on taking the tiles position and converting it to the index number that represents it in the array. As you well know, arrays cannot have a negative index. Here is some of my code: This generates the square (or rectangle) of tiles: //Scale is in tiles public void Generate(int sX, int sY) { scaleX = sX; scaleY = sY; for (int y = 0; y <= scaleY; y++) { tiles.Add(new List<Tile>()); for (int x = 0; x <= scaleX; x++) { tiles[tiles.Count - 1].Add(tileset.randomTile(x * tileset.TileSize, y * tileset.TileSize)); } } } Before I changed the code after realizing an array index couldn't be negative my for loops looked something like this to center the map around (0, 0): for (int y = -scaleY / 2; y <= scaleY / 2; y++) for (int x = -scaleX / 2; x <= scaleX / 2; x++) Here is the code that draws the tiles: int startX = (int)Math.Floor((player.Position.X - (graphics.Viewport.Width) - tileset.TileSize) / tileset.TileSize); int endX = (int)Math.Ceiling((player.Position.X + (graphics.Viewport.Width) + tileset.TileSize) / tileset.TileSize); int startY = (int)Math.Floor((player.Position.Y - (graphics.Viewport.Height) - tileset.TileSize) / tileset.TileSize); int endY = (int)Math.Ceiling((player.Position.Y + (graphics.Viewport.Height) + tileset.TileSize) / tileset.TileSize); for (int y = startY; y < endY; y++) { for (int x = startX; x < endX; x++) { if (x >= 0 && y >= 0 && x <= scaleX && y <= scaleY) tiles[y][x].Draw(spriteBatch); } } So to summarize what I'm asking: First, how do I randomly generate a top-down 2D map with different sections (not chunks per se, but areas with different tile sets) and second, how do I get past this negative array index issue?

    Read the article

  • Is there a code-generator to create DataTable definition block from Excel Work sheet?

    - by burak ozdogan
    Hi, Basically the thing I want to achieve is to have a data-table that I want to use in my unit tests. And when I run my unit tests, I do not want to read any excel file into a data-table -or any call to Db-. So, I would like to have method that returns a data-table with the values that I can use in my test. Is there already any written tool to read an excel sheet and generate a code that defines an ADO.Net DataTable? Thanks, burak ozdogan

    Read the article

  • Generate random number histogram using java

    - by Chewart
    Histogram -------------------------------------------------------- 1 ****(4) 2 ******(6) 3 ***********(11) 4 *****************(17) 5 **************************(26) 6 *************************(25) 7 *******(7) 8 ***(3) 9 (0) 10 *(1) -------------------------------------------------------- basically above is what my prgram needs to do.. im missing something somewhere any help would be great :) import java.util.Random; public class Histogram { /*This is a program to generate random number histogram between 1 and 100 and generate a table */ public static void main(String args[]) { int [] randarray = new int [80]; Random random = new Random(); System.out.println("Histogram"); System.out.println("---------"); int i ; for ( i = 0; i<randarray.length;i++) { int temp = random.nextInt(100); //random numbers up to number value 100 randarray[i] = temp; } int [] histo = new int [10]; for ( i = 0; i<10; i++) { /* %03d\t, this generates the random numbers to three decimal places so the numbers are generated with a full number or number with 00's or one 0*/ if (randarray[i] <= 10) { histo[i] = histo[i] + 1; //System.out.println("*"); } else if ( randarray[i] <= 20){ histo[i] = histo[i] + 1; } else if (randarray[i] <= 30){ histo[i] = histo[i] + 1; } else if ( randarray[i] <= 40){ histo[i] = histo[i] + 1; } else if (randarray[i] <= 50){ histo[i] = histo[i] + 1; } else if ( randarray[i] <=60){ histo[i] = histo[i] + 1; } else if ( randarray[i] <=70){ histo[i] = histo[i] + 1; } else if ( randarray[i] <=80){ histo[i] = histo[i] + 1; } else if ( randarray[i] <=90){ histo[i] = histo[i] + 1; } else if ( randarray[i] <=100){ histo[i] = histo[i] + 1; } switch (randarray[i]) { case 1: System.out.print("0-10 | "); break; case 2: System.out.print("11-20 | "); break; case 3: System.out.print("21-30 | "); break; case 4: System.out.print("31-40 | "); break; case 5: System.out.print("41-50 | "); break; case 6: System.out.print("51-60 | "); break; case 7: System.out.print("61-70 | "); break; case 8: System.out.print("71-80 | "); break; case 9: System.out.print("81-90 | "); break; case 10: System.out.print("91-100 | "); } for (int i = 0; i < 80; i++) { randomNumber = random.nextInt(100) index = (randomNumber - 1) / 2; histo[index]++; } } } }

    Read the article

  • Utility to record IO statistics (random/sequential, block sizes, read/write ratio) in Unix

    - by Michael Pearson
    As part of provisioning our new server (see other SF) I'd like to find out the following: ratio of random to sequential reads & writes amount of data read & written at a time (pref in histogram form) I can already figure out our reads/writes on a per-operation and overall data level using iostat & dstat, but I'd like to know more. For example, I'd like to know that we're mostly random 16kb reads, or a lot of sequential 64kb reads with random writes. We're (currently) on an Ubuntu 10.04 VM. Is there a utility that I can run that will record and present this information for me?

    Read the article

  • Hyphenate a random string to an exact format

    - by chrissygormley
    Hello, I am creating a random ID using the below code: from random import * import string # The characters to make up the random password chars = string.ascii_letters + string.digits def random_password(): return "".join(choice(chars) for x in range(32)) This will output something like: 60ff612332b741508bc4432e34ec1d3e I would like the format to be in this format: 60ff6123-32b7-4150-8bc4-432e34ec1d3e I was looking at the .split() method but can't see how to do this with a random id, also the hyphen's must be at these places so splitting them by a certain amount of digits is out. I'm asking is there a way to split these random id's by 8 number's then 4 etc. Thanks

    Read the article

  • C# Random of cordinates is linear

    - by Shawn Mclean
    My code is to generate random cordinates of lat and long within a bound: Random lastLat = new Random(); Random lastLon = new Random(); for (int i = 0; i < 50; i++) { int lat = lastLat.Next(516400146, 630304598); //18.51640014679267 - 18.630304598192915 int lon = lastLon.Next(224464416, 341194152); //-72.34119415283203 - -72.2244644165039 SamplePostData d0 = new SamplePostData(); d0.Location = new Location(Convert.ToDouble("18." + lat), Convert.ToDouble("-72." + lon)); AddPushpin(d0); } My output looks like this: Is there something wrong with how my numbers are generated?

    Read the article

  • Random touchpad and keyboard freezes on new installation

    - by ancaleth
    My touchpad and keyboard freeze up on my newly installed Ubuntu 10.10. They remain frozen until you shut down manually. No keys work, cursor doesn't move - it's like a screenshot. I was using Ubuntu 10.4 via wubi before on this Laptop where this problem never occurred. (I did not migrate wubi or upgrade to 10.10, it's a fresh start. 64-bit on Dell Studio, plenty of RAM, plenty of free space on partition etc.) I can't say there is a pattern yet, once it happened during the download of packages with the Update Manager, once it was just using Firefox, no other program running. In between these crashes the laptop was booted once, updates were installed etc., firefox was used and there weren't any problems. Both crashes should be in the attached kern.log and I noticed there were some error problems before the last crash (at the end, obviously). It seems the wireless was experiencing problems. This wasn't noticed on the user end, since the touchpad + keyboard were already frozen. kern.log: http://paste.ubuntu.com/552617/ How can the freezes be fixed? Edit: I will try Ctrl+Alt+F1 and then Ctrl+Alt+F7 when next freeze occurs, to see if it works again after this, as suggested here. But the keyboard seemed pretty frozen to me.

    Read the article

  • random lags in music when playing on any music player

    - by harsh
    guys I have experienced this issue in most of all the music players i tried in ubuntu 12.10. When ever I play a track I experience certain issue, like the track just skipped a second or two. This happens occasionally but at least 4-5 times when ever i play any music track. The actual thing is that the track fast forwards by just 1 or 2 secs and then runs on normal rate. This used to happen during a video, but now it doesn't. But for the music this issue has not stopped. ASRock mootherboard,core2 duo. Also I get ubuntu 12.10 has experienced an internal error(its regarding nautilus). Also the Software Update always gives an internet connection connection error whereas I am able to browse the web and download with ease. Please reply..

    Read the article

  • Random Monday Thoughs

    - by Terry Goldman
    On this Monday morning my thoughts center on why is it so hard to embrace governance, any form of governance for that matter, be it software development governance, SOA governance, data governance, IT governance, so on a so fourth?Most customers that I meet tend to think that they don't need don't need governance as all is good within the enterprise. The question I generally pose to colleges and customers, is you have to think of governance as an insurance policy. Take of instance, if you just bought a new car, perhaps your "dream" car, would you drive it on the open streets without having the car insured? Probably not.Governance is what insurance is to new cars, be it to SOA, IT transformations and software development. Governance is a insurance policy against risk of failure. Now once I put it in this context, ask yourself, does governance have value to your organization? Most people now get it. Once the seed of governance is planted at the executive level of an organization, it becomes a exercise in planting an that idea into key personnel within the organization. Then the justification for governance grows and grows across the enterprise.Thats my food for though in this Monday morning.FYI, stay tuned for an upcoming multi-part article on using Oracle Enterprise Repository to build a Enterprise Continuum as described in TOGAF v9.0.

    Read the article

  • gVim characters unreadable at random times

    - by Mussnoon
    Screenshot - Anyone know what causes it and how to fix? It only started happening today, while I've been using gVim for a couple of months now. Update: Output of locale LANG=en_US.utf8 LC_CTYPE="en_US.utf8" LC_NUMERIC="en_US.utf8" LC_TIME="en_US.utf8" LC_COLLATE="en_US.utf8" LC_MONETARY="en_US.utf8" LC_MESSAGES="en_US.utf8" LC_PAPER="en_US.utf8" LC_NAME="en_US.utf8" LC_ADDRESS="en_US.utf8" LC_TELEPHONE="en_US.utf8" LC_MEASUREMENT="en_US.utf8" LC_IDENTIFICATION="en_US.utf8" LC_ALL=

    Read the article

  • PHP blunders with random numbers

    <b>The H Open:</b> "Security expert Andreas Bogk warns that, despite recent PHP improvements, the session IDs of users who are logged into PHP applications remain guessable. Upon close examination, the alleged improvements display frightening weaknesses."

    Read the article

  • Running 12.04 on a Dell Inspiron 1545 having random system lockups

    - by Kris
    I just reinstalled a fresh 12.04 because I couldn't even get booted on my previous installation anymore. I just installed 8GB of ram on this laptop, but the problem happened even before this, and all I have installed in this run on Ubuntu is: ia32libs, Oracle JDK7 and the 32bit JRE junipernc jupiter The laptop has never been used very heavily, so could someone get back to me on this, let me know what further information you need about my machine, or files to upload. Thanks!

    Read the article

  • Gnome trash on cifs mount random behaviour

    - by BobPenguin
    Hello everyone, I'm seeing some weird behaviour in Ubuntu 10.04. I have a cifs mount that's mounted by fstab as follows: //192.168.1.1/share /media/storage cifs_netdev,username=guest,password="",uid=1000,guid=100,file_mode=0777,dir_mode=0777 0 0 I can mount the share using: sudo mount -a my user can then access it, create and delete files. The deleted files appear in the gnome trash applet. A folder /media/storage/.Trash-1000 is created automatically. When I log out, restart the machine and log in, the cifs share is mounted but the trash applet is empty. If I unmount the share with sudo umount /media/share then remount with sudo mount -a the trash applet displays the contents of the .trash-1000 folder! It gets stranger...sometimes after umount then mount -a the trash is STILL empty, but another round of umount then mount -a fixes it. It seems like the trash applet is "forgetting" to scan the /media/storage mount point and is not always finding the .trash-1000 folder at that mount point. Even when the trash applet is not displaying any trash from /media/storage/.trash-1000 I can still delete things from the /media/storage and they're moved to the .trash-1000 folder. So I conclude there's a bug in the trash applet...anyone know how to fix it?

    Read the article

  • Xubuntu 12.04 : Random boot to black screen

    - by Thibaud Ruelle
    My xubuntu 12.04 has worked flawlessly since install in September. However, lately I randomly have the following boot issue : The computer boots to grub, and after choosing xubuntu either boots normally or boots to a black screen. Here are some observations I have made : The black screen seems to happen randomly. The black screen does not seem to happen in safe mode (- nomodeset in grub). The black screen does not allow me to ctrl + alt + F1-6 into a terminal. The black screen allows me to use SysRq keys (Alt + SysRq + K does not work though). The black screen often happens on first boot in several hours and the computer usually boots normally after a RSEINUB. When the computer boots I get "SP5100 TCO timer: mmio address 0xfec000f0 already in use" at startup and "Could not write bytes: broken pipe" at shutdown. However research on these errors did not yield answers to my particular issue. Comparing Xorg.0.log (successful boot) and Xorg.0.log.old (black screen), and reading the answers to similar problem, it seems that I might have a X driver issue. However the system worked flawlessly since lately. Additional info on my system : ACER AO722 C62kk Operating system : 3.2.0-31-generic ubuntu Edit : I made a fresh install of Xubuntu 12.04 x64, the issue is still there ... (I have a separate /home so config. files were not erased). Edit 2 : I followed troubleshooting blank screen, so my new observations are without quiet and splash in grub : When the system boots normally, the screen goes black after grub then lights up and displays text information then goes to login screen. (After that the desktop starting time vary substantially, which is new and may be a separate issue ?). When the boot fails, after grub the screen goes black, lights up, goes black, lights up again and most times goes black again. At this point it responds to Alt+SysReq K by lighting up but no more, and has to be rebooted through Alt+SysReq+ RSEINUB. Thank you for your time and attention in advance ! Thibaud Ruelle

    Read the article

< Previous Page | 13 14 15 16 17 18 19 20 21 22 23 24  | Next Page >