Search Results

Search found 28873 results on 1155 pages for 'simple injector'.

Page 311/1155 | < Previous Page | 307 308 309 310 311 312 313 314 315 316 317 318  | Next Page >

  • What should be contained in a game scene graph?

    - by Bunkai.Satori
    Would you help me to clarify, please, what what exactly should be contained within a game scene graph? See the following list, please: Game Actors? (obviously yes, all the objects changing state should be the major prart of the Scene Graph) Simple static game ojbects? (I mean ojects places in the background that do not get animated, neither do they collide) Game Triggers? Game Lights? Game Cameras? Weapon Bullets? Game Explosions and Special Effects? The above considered object types. Now to the coverage of the scene graph: Should a scene graph contain the whole game level map since the level start, or should it contain only the visible portion of the map? If the second is true, it would mean that scene graph would be continuously updated, by adding/removing game objects, as the player moves. However, containing only the visible are of the map obviously would be much faster to traverse and update.

    Read the article

  • NoSQL Java API for MySQL Cluster: Questions & Answers

    - by Mat Keep
    The MySQL Cluster engineering team recently ran a live webinar, available now on-demand demonstrating the ClusterJ and ClusterJPA NoSQL APIs for MySQL Cluster, and how these can be used in building real-time, high scale Java-based services that require continuous availability. Attendees asked a number of great questions during the webinar, and I thought it would be useful to share those here, so others are also able to learn more about the Java NoSQL APIs. First, a little bit about why we developed these APIs and why they are interesting to Java developers. ClusterJ and Cluster JPA ClusterJ is a Java interface to MySQL Cluster that provides either a static or dynamic domain object model, similar to the data model used by JDO, JPA, and Hibernate. A simple API gives users extremely high performance for common operations: insert, delete, update, and query. ClusterJPA works with ClusterJ to extend functionality, including - Persistent classes - Relationships - Joins in queries - Lazy loading - Table and index creation from object model By eliminating data transformations via SQL, users get lower data access latency and higher throughput. In addition, Java developers have a more natural programming method to directly manage their data, with a complete, feature-rich solution for Object/Relational Mapping. As a result, the development of Java applications is simplified with faster development cycles resulting in accelerated time to market for new services. MySQL Cluster offers multiple NoSQL APIs alongside Java: - Memcached for a persistent, high performance, write-scalable Key/Value store, - HTTP/REST via an Apache module - C++ via the NDB API for the lowest absolute latency. Developers can use SQL as well as NoSQL APIs for access to the same data set via multiple query patterns – from simple Primary Key lookups or inserts to complex cross-shard JOINs using Adaptive Query Localization Marrying NoSQL and SQL access to an ACID-compliant database offers developers a number of benefits. MySQL Cluster’s distributed, shared-nothing architecture with auto-sharding and real time performance makes it a great fit for workloads requiring high volume OLTP. Users also get the added flexibility of being able to run real-time analytics across the same OLTP data set for real-time business insight. OK – hopefully you now have a better idea of why ClusterJ and JPA are available. Now, for the Q&A. Q & A Q. Why would I use Connector/J vs. ClusterJ? A. Partly it's a question of whether you prefer to work with SQL (Connector/J) or objects (ClusterJ). Performance of ClusterJ will be better as there is no need to pass through the MySQL Server. A ClusterJ operation can only act on a single table (e.g. no joins) - ClusterJPA extends that capability Q. Can I mix different APIs (ie ClusterJ, Connector/J) in our application for different query types? A. Yes. You can mix and match all of the API types, SQL, JDBC, ODBC, ClusterJ, Memcached, REST, C++. They all access the exact same data in the data nodes. Update through one API and new data is instantly visible to all of the others. Q. How many TCP connections would a SessionFactory instance create for a cluster of 8 data nodes? A. SessionFactory has a connection to the mgmd (management node) but otherwise is just a vehicle to create Sessions. Without using connection pooling, a SessionFactory will have one connection open with each data node. Using optional connection pooling allows multiple connections from the SessionFactory to increase throughput. Q. Can you give details of how Cluster J optimizes sharding to enhance performance of distributed query processing? A. Each data node in a cluster runs a Transaction Coordinator (TC), which begins and ends the transaction, but also serves as a resource to operate on the result rows. While an API node (such as a ClusterJ process) can send queries to any TC/data node, there are performance gains if the TC is where most of the result data is stored. ClusterJ computes the shard (partition) key to choose the data node where the row resides as the TC. Q. What happens if we perform two primary key lookups within the same transaction? Are they sent to the data node in one transaction? A. ClusterJ will send identical PK lookups to the same data node. Q. How is distributed query processing handled by MySQL Cluster ? A. If the data is split between data nodes then all of the information will be transparently combined and passed back to the application. The session will connect to a data node - typically by hashing the primary key - which then interacts with its neighboring nodes to collect the data needed to fulfil the query. Q. Can I use Foreign Keys with MySQL Cluster A. Support for Foreign Keys is included in the MySQL Cluster 7.3 Early Access release Summary The NoSQL Java APIs are packaged with MySQL Cluster, available for download here so feel free to take them for a spin today! Key Resources MySQL Cluster on-line demo  MySQL ClusterJ and JPA On-demand webinar  MySQL ClusterJ and JPA documentation MySQL ClusterJ and JPA whitepaper and tutorial

    Read the article

  • The PASS Elections Review Committee Needs Your Feedback

    - by andyleonard
    Introduction PASS has had an ERC (Elections Review Committee) forum running for a few months now. There's been surprisingly little feedback, though lots of reads. Here's what it looks like tonight: That's 1,662 views and 37 replies by my count. Not very many replies... Jump In! Now's the time to let PASS know what you think about the current elections process. The ERC members are good people who are trying to make things better. If you have something to add - as simple as "love it!" or "hate it!"...(read more)

    Read the article

  • So what are zones really?

    - by Bertrand Le Roy
    There is a (not so) particular kind of shape in Orchard: zones. Functionally, zones are places where other shapes can render. There are top-level zones, the ones defined on Layout, where widgets typically go, and there are local zones that can be defined anywhere. These local zones are what you target in placement.info. Creating a zone is easy because it really is just an empty shape. Most themes include a helper for it: Func<dynamic, dynamic> Zone = x => Display(x); .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } With this helper, you can create a zone by simply writing: @Zone(Model.Header) .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Let's deconstruct what's happening here with that weird Lambda. In the Layout template where we are working, the Model is the Layout shape itself, so Model.Header is really creating a new Header shape under Layout, or getting a reference to it if it already exists. The Zone function is then called on that object, which is equivalent to calling Display. In other words, you could have just written the following to get the exact same effect: @Display(Model.Header) The Zone helper function only exists to make the intent very explicit. Now here's something interesting: while this works in the Layout template, you can also make it work from any deeper-nested template and still create top-level zones. The difference is that wherever you are, Model is not the layout anymore so you need to access it in a different way: @Display(WorkContext.Layout.Header) This is still doing the exact same thing as above. One thing to know is that for top-level zones to be usable from the widget editing UI, you need one more thing, which is to specify it in the theme's manifest: Name: Contoso Author: The Orchard Team Description: A subtle and simple CMS themeVersion: 1.1 Tags: business, cms, modern, simple, subtle, product, service Website: http://www.orchardproject.net Zones: Header, Navigation, HomeFeaturedImage, HomeFeaturedHeadline, Messages, Content, ContentAside, TripelFirst, TripelSecond, TripelThird, Footer Local zones are just ordinary shapes like global zones, the only difference being that they are created on a deeper shape than layout. For example, in Content.cshtml, you can find our good old code fro creating a header zone: @Display(Model.Header) The difference here is that Model is no longer the Layout shape, so that zone will be local. The name of that local zone is what you specify in placement.info, for example: <Place Parts_Common_Metadata_Summary="Header:1"/> Now here's the really interesting part: zones do not even know that they are zones, and in fact any shape can be substituted. That means that if you want to add new shapes to the shape that some part has been emitting from its driver for example, you can absolutely do that. And because zones are so barebones as shapes go, they can be created the first time they are accessed. This is what enables us to add shapes into a zone before the code that you would think creates it has even run. For example, in the Layout.cshtml template in TheThemeMachine, the BadgeOfHonor shape is being injected into the Footer zone on line 47, even though that zone will really be "created" on line 168.

    Read the article

  • Why does the word "Pythonic" exist?

    - by Billy ONeal
    Honestly, I hate the word "Pythonic" -- it's used as a simple synonym of "good" in many circles, and I think that's pretentious. Those who use it are silently saying that good code cannot be written in a language other than Python. Not saying Python is a bad language, but it's certainly not the "end all be all language to solve ALL of everyone's problems forever!" (Because that language does not exist). What it seems like people who use this word really mean is "idiomatic" rather than "Pythonic" -- and of course the word "idiomatic" already exists. Therefore I wonder: Why does the word "Pythonic" exist?

    Read the article

  • Rendering of 2d water

    - by luke
    Suppose you have a nice way to move your 2D particles in order to simulate a fluid (like water). Any ideas on how to render it? Consider the fact that the game is a 2D game. The perspective is like this (the first image i have found): an example of 2d water. The water will be contained in boxes that can be broken in order to let it fall down and interact with other objects. The most simple way that comes to my mind is to use a small image for each particle. I am interested in hearing more ways of rendering water. Thank you.

    Read the article

  • Alternative to pyGame ?

    - by stighy
    Hi, i'm learning something about game programming from a book about "pyGame". pyGame is simple, but... python is a little complex and different from my previous knoweledge about programming. I know "classical" language: C# (also C/C++), Java ... I know a lot of people love Python but for me is a little harder to learn! So i'm looking something like "pyGame" but for java or for c# ... A library with which i can do almost the same thing i can do with pygame (so .. do more with less code ... and headhace). Thank you Ps: excuse my "poor" english!

    Read the article

  • PTLQueue : a scalable bounded-capacity MPMC queue

    - by Dave
    Title: Fast concurrent MPMC queue -- I've used the following concurrent queue algorithm enough that it warrants a blog entry. I'll sketch out the design of a fast and scalable multiple-producer multiple-consumer (MPSC) concurrent queue called PTLQueue. The queue has bounded capacity and is implemented via a circular array. Bounded capacity can be a useful property if there's a mismatch between producer rates and consumer rates where an unbounded queue might otherwise result in excessive memory consumption by virtue of the container nodes that -- in some queue implementations -- are used to hold values. A bounded-capacity queue can provide flow control between components. Beware, however, that bounded collections can also result in resource deadlock if abused. The put() and take() operators are partial and wait for the collection to become non-full or non-empty, respectively. Put() and take() do not allocate memory, and are not vulnerable to the ABA pathologies. The PTLQueue algorithm can be implemented equally well in C/C++ and Java. Partial operators are often more convenient than total methods. In many use cases if the preconditions aren't met, there's nothing else useful the thread can do, so it may as well wait via a partial method. An exception is in the case of work-stealing queues where a thief might scan a set of queues from which it could potentially steal. Total methods return ASAP with a success-failure indication. (It's tempting to describe a queue or API as blocking or non-blocking instead of partial or total, but non-blocking is already an overloaded concurrency term. Perhaps waiting/non-waiting or patient/impatient might be better terms). It's also trivial to construct partial operators by busy-waiting via total operators, but such constructs may be less efficient than an operator explicitly and intentionally designed to wait. A PTLQueue instance contains an array of slots, where each slot has volatile Turn and MailBox fields. The array has power-of-two length allowing mod/div operations to be replaced by masking. We assume sensible padding and alignment to reduce the impact of false sharing. (On x86 I recommend 128-byte alignment and padding because of the adjacent-sector prefetch facility). Each queue also has PutCursor and TakeCursor cursor variables, each of which should be sequestered as the sole occupant of a cache line or sector. You can opt to use 64-bit integers if concerned about wrap-around aliasing in the cursor variables. Put(null) is considered illegal, but the caller or implementation can easily check for and convert null to a distinguished non-null proxy value if null happens to be a value you'd like to pass. Take() will accordingly convert the proxy value back to null. An advantage of PTLQueue is that you can use atomic fetch-and-increment for the partial methods. We initialize each slot at index I with (Turn=I, MailBox=null). Both cursors are initially 0. All shared variables are considered "volatile" and atomics such as CAS and AtomicFetchAndIncrement are presumed to have bidirectional fence semantics. Finally T is the templated type. I've sketched out a total tryTake() method below that allows the caller to poll the queue. tryPut() has an analogous construction. Zebra stripping : alternating row colors for nice-looking code listings. See also google code "prettify" : https://code.google.com/p/google-code-prettify/ Prettify is a javascript module that yields the HTML/CSS/JS equivalent of pretty-print. -- pre:nth-child(odd) { background-color:#ff0000; } pre:nth-child(even) { background-color:#0000ff; } border-left: 11px solid #ccc; margin: 1.7em 0 1.7em 0.3em; background-color:#BFB; font-size:12px; line-height:65%; " // PTLQueue : Put(v) : // producer : partial method - waits as necessary assert v != null assert Mask = 1 && (Mask & (Mask+1)) == 0 // Document invariants // doorway step // Obtain a sequence number -- ticket // As a practical concern the ticket value is temporally unique // The ticket also identifies and selects a slot auto tkt = AtomicFetchIncrement (&PutCursor, 1) slot * s = &Slots[tkt & Mask] // waiting phase : // wait for slot's generation to match the tkt value assigned to this put() invocation. // The "generation" is implicitly encoded as the upper bits in the cursor // above those used to specify the index : tkt div (Mask+1) // The generation serves as an epoch number to identify a cohort of threads // accessing disjoint slots while s-Turn != tkt : Pause assert s-MailBox == null s-MailBox = v // deposit and pass message Take() : // consumer : partial method - waits as necessary auto tkt = AtomicFetchIncrement (&TakeCursor,1) slot * s = &Slots[tkt & Mask] // 2-stage waiting : // First wait for turn for our generation // Acquire exclusive "take" access to slot's MailBox field // Then wait for the slot to become occupied while s-Turn != tkt : Pause // Concurrency in this section of code is now reduced to just 1 producer thread // vs 1 consumer thread. // For a given queue and slot, there will be most one Take() operation running // in this section. // Consumer waits for producer to arrive and make slot non-empty // Extract message; clear mailbox; advance Turn indicator // We have an obvious happens-before relation : // Put(m) happens-before corresponding Take() that returns that same "m" for T v = s-MailBox if v != null : s-MailBox = null ST-ST barrier s-Turn = tkt + Mask + 1 // unlock slot to admit next producer and consumer return v Pause tryTake() : // total method - returns ASAP with failure indication for auto tkt = TakeCursor slot * s = &Slots[tkt & Mask] if s-Turn != tkt : return null T v = s-MailBox // presumptive return value if v == null : return null // ratify tkt and v values and commit by advancing cursor if CAS (&TakeCursor, tkt, tkt+1) != tkt : continue s-MailBox = null ST-ST barrier s-Turn = tkt + Mask + 1 return v The basic idea derives from the Partitioned Ticket Lock "PTL" (US20120240126-A1) and the MultiLane Concurrent Bag (US8689237). The latter is essentially a circular ring-buffer where the elements themselves are queues or concurrent collections. You can think of the PTLQueue as a partitioned ticket lock "PTL" augmented to pass values from lock to unlock via the slots. Alternatively, you could conceptualize of PTLQueue as a degenerate MultiLane bag where each slot or "lane" consists of a simple single-word MailBox instead of a general queue. Each lane in PTLQueue also has a private Turn field which acts like the Turn (Grant) variables found in PTL. Turn enforces strict FIFO ordering and restricts concurrency on the slot mailbox field to at most one simultaneous put() and take() operation. PTL uses a single "ticket" variable and per-slot Turn (grant) fields while MultiLane has distinct PutCursor and TakeCursor cursors and abstract per-slot sub-queues. Both PTL and MultiLane advance their cursor and ticket variables with atomic fetch-and-increment. PTLQueue borrows from both PTL and MultiLane and has distinct put and take cursors and per-slot Turn fields. Instead of a per-slot queues, PTLQueue uses a simple single-word MailBox field. PutCursor and TakeCursor act like a pair of ticket locks, conferring "put" and "take" access to a given slot. PutCursor, for instance, assigns an incoming put() request to a slot and serves as a PTL "Ticket" to acquire "put" permission to that slot's MailBox field. To better explain the operation of PTLQueue we deconstruct the operation of put() and take() as follows. Put() first increments PutCursor obtaining a new unique ticket. That ticket value also identifies a slot. Put() next waits for that slot's Turn field to match that ticket value. This is tantamount to using a PTL to acquire "put" permission on the slot's MailBox field. Finally, having obtained exclusive "put" permission on the slot, put() stores the message value into the slot's MailBox. Take() similarly advances TakeCursor, identifying a slot, and then acquires and secures "take" permission on a slot by waiting for Turn. Take() then waits for the slot's MailBox to become non-empty, extracts the message, and clears MailBox. Finally, take() advances the slot's Turn field, which releases both "put" and "take" access to the slot's MailBox. Note the asymmetry : put() acquires "put" access to the slot, but take() releases that lock. At any given time, for a given slot in a PTLQueue, at most one thread has "put" access and at most one thread has "take" access. This restricts concurrency from general MPMC to 1-vs-1. We have 2 ticket locks -- one for put() and one for take() -- each with its own "ticket" variable in the form of the corresponding cursor, but they share a single "Grant" egress variable in the form of the slot's Turn variable. Advancing the PutCursor, for instance, serves two purposes. First, we obtain a unique ticket which identifies a slot. Second, incrementing the cursor is the doorway protocol step to acquire the per-slot mutual exclusion "put" lock. The cursors and operations to increment those cursors serve double-duty : slot-selection and ticket assignment for locking the slot's MailBox field. At any given time a slot MailBox field can be in one of the following states: empty with no pending operations -- neutral state; empty with one or more waiting take() operations pending -- deficit; occupied with no pending operations; occupied with one or more waiting put() operations -- surplus; empty with a pending put() or pending put() and take() operations -- transitional; or occupied with a pending take() or pending put() and take() operations -- transitional. The partial put() and take() operators can be implemented with an atomic fetch-and-increment operation, which may confer a performance advantage over a CAS-based loop. In addition we have independent PutCursor and TakeCursor cursors. Critically, a put() operation modifies PutCursor but does not access the TakeCursor and a take() operation modifies the TakeCursor cursor but does not access the PutCursor. This acts to reduce coherence traffic relative to some other queue designs. It's worth noting that slow threads or obstruction in one slot (or "lane") does not impede or obstruct operations in other slots -- this gives us some degree of obstruction isolation. PTLQueue is not lock-free, however. The implementation above is expressed with polite busy-waiting (Pause) but it's trivial to implement per-slot parking and unparking to deschedule waiting threads. It's also easy to convert the queue to a more general deque by replacing the PutCursor and TakeCursor cursors with Left/Front and Right/Back cursors that can move either direction. Specifically, to push and pop from the "left" side of the deque we would decrement and increment the Left cursor, respectively, and to push and pop from the "right" side of the deque we would increment and decrement the Right cursor, respectively. We used a variation of PTLQueue for message passing in our recent OPODIS 2013 paper. ul { list-style:none; padding-left:0; padding:0; margin:0; margin-left:0; } ul#myTagID { padding: 0px; margin: 0px; list-style:none; margin-left:0;} -- -- There's quite a bit of related literature in this area. I'll call out a few relevant references: Wilson's NYU Courant Institute UltraComputer dissertation from 1988 is classic and the canonical starting point : Operating System Data Structures for Shared-Memory MIMD Machines with Fetch-and-Add. Regarding provenance and priority, I think PTLQueue or queues effectively equivalent to PTLQueue have been independently rediscovered a number of times. See CB-Queue and BNPBV, below, for instance. But Wilson's dissertation anticipates the basic idea and seems to predate all the others. Gottlieb et al : Basic Techniques for the Efficient Coordination of Very Large Numbers of Cooperating Sequential Processors Orozco et al : CB-Queue in Toward high-throughput algorithms on many-core architectures which appeared in TACO 2012. Meneghin et al : BNPVB family in Performance evaluation of inter-thread communication mechanisms on multicore/multithreaded architecture Dmitry Vyukov : bounded MPMC queue (highly recommended) Alex Otenko : US8607249 (highly related). John Mellor-Crummey : Concurrent queues: Practical fetch-and-phi algorithms. Technical Report 229, Department of Computer Science, University of Rochester Thomasson : FIFO Distributed Bakery Algorithm (very similar to PTLQueue). Scott and Scherer : Dual Data Structures I'll propose an optimization left as an exercise for the reader. Say we wanted to reduce memory usage by eliminating inter-slot padding. Such padding is usually "dark" memory and otherwise unused and wasted. But eliminating the padding leaves us at risk of increased false sharing. Furthermore lets say it was usually the case that the PutCursor and TakeCursor were numerically close to each other. (That's true in some use cases). We might still reduce false sharing by incrementing the cursors by some value other than 1 that is not trivially small and is coprime with the number of slots. Alternatively, we might increment the cursor by one and mask as usual, resulting in a logical index. We then use that logical index value to index into a permutation table, yielding an effective index for use in the slot array. The permutation table would be constructed so that nearby logical indices would map to more distant effective indices. (Open question: what should that permutation look like? Possibly some perversion of a Gray code or De Bruijn sequence might be suitable). As an aside, say we need to busy-wait for some condition as follows : "while C == 0 : Pause". Lets say that C is usually non-zero, so we typically don't wait. But when C happens to be 0 we'll have to spin for some period, possibly brief. We can arrange for the code to be more machine-friendly with respect to the branch predictors by transforming the loop into : "if C == 0 : for { Pause; if C != 0 : break; }". Critically, we want to restructure the loop so there's one branch that controls entry and another that controls loop exit. A concern is that your compiler or JIT might be clever enough to transform this back to "while C == 0 : Pause". You can sometimes avoid this by inserting a call to a some type of very cheap "opaque" method that the compiler can't elide or reorder. On Solaris, for instance, you could use :"if C == 0 : { gethrtime(); for { Pause; if C != 0 : break; }}". It's worth noting the obvious duality between locks and queues. If you have strict FIFO lock implementation with local spinning and succession by direct handoff such as MCS or CLH,then you can usually transform that lock into a queue. Hidden commentary and annotations - invisible : * And of course there's a well-known duality between queues and locks, but I'll leave that topic for another blog post. * Compare and contrast : PTLQ vs PTL and MultiLane * Equivalent : Turn; seq; sequence; pos; position; ticket * Put = Lock; Deposit Take = identify and reserve slot; wait; extract & clear; unlock * conceptualize : Distinct PutLock and TakeLock implemented as ticket lock or PTL Distinct arrival cursors but share per-slot "Turn" variable provides exclusive role-based access to slot's mailbox field put() acquires exclusive access to a slot for purposes of "deposit" assigns slot round-robin and then acquires deposit access rights/perms to that slot take() acquires exclusive access to slot for purposes of "withdrawal" assigns slot round-robin and then acquires withdrawal access rights/perms to that slot At any given time, only one thread can have withdrawal access to a slot at any given time, only one thread can have deposit access to a slot Permissible for T1 to have deposit access and T2 to simultaneously have withdrawal access * round-robin for the purposes of; role-based; access mode; access role mailslot; mailbox; allocate/assign/identify slot rights; permission; license; access permission; * PTL/Ticket hybrid Asymmetric usage ; owner oblivious lock-unlock pairing K-exclusion add Grant cursor pass message m from lock to unlock via Slots[] array Cursor performs 2 functions : + PTL ticket + Assigns request to slot in round-robin fashion Deconstruct protocol : explication put() : allocate slot in round-robin fashion acquire PTL for "put" access store message into slot associated with PTL index take() : Acquire PTL for "take" access // doorway step seq = fetchAdd (&Grant, 1) s = &Slots[seq & Mask] // waiting phase while s-Turn != seq : pause Extract : wait for s-mailbox to be full v = s-mailbox s-mailbox = null Release PTL for both "put" and "take" access s-Turn = seq + Mask + 1 * Slot round-robin assignment and lock "doorway" protocol leverage the same cursor and FetchAdd operation on that cursor FetchAdd (&Cursor,1) + round-robin slot assignment and dispersal + PTL/ticket lock "doorway" step waiting phase is via "Turn" field in slot * PTLQueue uses 2 cursors -- put and take. Acquire "put" access to slot via PTL-like lock Acquire "take" access to slot via PTL-like lock 2 locks : put and take -- at most one thread can access slot's mailbox Both locks use same "turn" field Like multilane : 2 cursors : put and take slot is simple 1-capacity mailbox instead of queue Borrow per-slot turn/grant from PTL Provides strict FIFO Lock slot : put-vs-put take-vs-take at most one put accesses slot at any one time at most one put accesses take at any one time reduction to 1-vs-1 instead of N-vs-M concurrency Per slot locks for put/take Release put/take by advancing turn * is instrumental in ... * P-V Semaphore vs lock vs K-exclusion * See also : FastQueues-excerpt.java dice-etc/queue-mpmc-bounded-blocking-circular-xadd/ * PTLQueue is the same as PTLQB - identical * Expedient return; ASAP; prompt; immediately * Lamport's Bakery algorithm : doorway step then waiting phase Threads arriving at doorway obtain a unique ticket number Threads enter in ticket order * In the terminology of Reed and Kanodia a ticket lock corresponds to the busy-wait implementation of a semaphore using an eventcount and a sequencer It can also be thought of as an optimization of Lamport's bakery lock was designed for fault-tolerance rather than performance Instead of spinning on the release counter, processors using a bakery lock repeatedly examine the tickets of their peers --

    Read the article

  • Dynamic Bursting ... no really!

    - by Tim Dexter
    If any of you have seen me or my colleagues present BI Publisher to you then we have hopefully mentioned 'bursting.' You may have even seen a demo where we talk about being able to take a batch of data, say invoices. Then split them by some criteria, say customer id; format them with a template; generate the output and then deliver the documents to the recipients with a click. We and especially I, always say this can be completely dynamic! By this I mean, that you could store customer preferences in a database. What layout would each customer like; what output format they would like and how they would like the document delivered. We (I) talk a good talk, but typically don't do the walk in a demo. We hard code everything in the bursting query or bursting control file to get the concept across. But no more peeps! I have finally put together a dynamic bursting demo! Its been minutes in the making but its been tough to find those minutes! Read on ... It's nothing amazing in terms of making the burst dynamic. I created a CUSTOMER_PREFS table with some simple UI in an APEX application so that I can maintain their requirements. In EBS you have descriptive flexfields that could do the same thing or probably even 'contact' fields to store most of the info. Here's my table structure: Name                           Type ------------------------------ -------- CUSTOMER_ID                    NUMBER(6) TEMPLATE_TYPE                  VARCHAR2(20) TEMPLATE_NAME                  VARCHAR2(120) OUTPUT_FORMAT                  VARCHAR2(20) DELIVERY_CHANNEL               VARCHAR2(50) EMAIL                          VARCHAR2(255) FAX                            VARCHAR2(20) ATTACH                         VARCHAR2(20) FILE_LOC                       VARCHAR2(255) Simple enough right? Just need CUSTOMER_ID as the key for the bursting engine to join it to the customer data at burst time. I have not covered the full delivery options, just email, fax and file location. Remember, its a demo people :0) However the principal is exactly the same for each delivery type. They each have a set of attributes that need to be provided and you will need to handle that in your bursting query. On a side note, in EBS, you use a bursting control file, you can apply the same principals that I'm laying out here you just need to get the customer bursting info into the XML data stream so that you can refer to it in the control file using XPATH expressions. Next, we need to look up what attributes or parameters are required for each delivery method. that can be found in the documentation here.  Now we know the combinations of parameters and delivery methods we can construct the query using a series a decode statements: select distinct cp.customer_id "KEY", cp.template_name TEMPLATE, cp.template_type TEMPLATE_FORMAT, 'en-US' LOCALE, cp.output_format OUTPUT_FORMAT, 'false' SAVE_FORMAT, cp.delivery_channel DEL_CHANNEL, decode(cp.delivery_channel,'FILE', cp.file_loc , 'EMAIL', cp.email , 'FAX', cp.fax) PARAMETER1, decode(cp.delivery_channel,'FILE', c.cust_last_name||'_orders.pdf' ,'EMAIL','[email protected]' ,'FAX', 'faxserver.com') PARAMETER2, decode(cp.delivery_channel,'FILE',NULL ,'EMAIL','[email protected]' ,'FAX', null) PARAMETER3, decode(cp.delivery_channel,'FILE',NULL ,'EMAIL','Your current orders' ,'FAX',NULL) PARAMETER4, decode(cp.delivery_channel,'FILE',NULL ,'EMAIL','Please find attached a copy of your current orders with BI Publisher, Inc' ,'FAX',NULL) PARAMETER5, decode(cp.delivery_channel,'FILE',NULL ,'EMAIL','false' ,'FAX',NULL) PARAMETER6, decode(cp.delivery_channel,'FILE',NULL ,'EMAIL','[email protected]' ,'FAX',NULL) PARAMETER7 from cust_prefs cp, customers c, orders_view ov where cp.customer_id = c.customer_id and cp.customer_id = ov.customer_id order by cp.customer_id Pretty straightforward, just need to test, test, test, the query and ensure it's bringing back the correct data based on each customers preferences. Notice the NULL values for parameters that are not relevant for a given delivery channel. You should end up with bursting control data that the bursting engine can use:  Now, your users can run the burst and documents will be formatted, generated and delivered based on the customer prefs. If you're interested in the example, I have used the sample OE schema data for the base report. The report files and CUST_PREFS table are zipped up here. The zip contains the data model (.xdmz), the report and templates (.xdoz) and the sql scripts to create and load data to the CUST_PREFS table.  Once you load the report into the catalog, you'll need to create the OE data connection and point the data model at it. You'll probably need to re-point the report to the data model too. Happy Bursting!

    Read the article

  • Mozilla publie la version alpha d'Account Manager, un plugin pour Firefox pour la gestion de l%u2019

    Mozilla publie la version alpha d'Account Manager, un plugin pour Firefox pour la gestion de l'identité en ligne La fondation Mozilla vient de lancer la version Alpha d'Account Manager, un plugin pour Firefox qui sert à simplifier l'indentification des utilisateurs sur le net. [IMG]http://djug.developpez.com/rsc/account-manager.jpg[/IMG] Cette première version facilitera aux utilisateurs l'identification aux sites populaires comme Google, Facebook et Yahoo en cherchant les informations nécessaires dans le gestionnaire des mots de passe du navigateur. Ce plugin permettra de passer d'un compte à un autre sur le même site par un simple clic, et propose également l'inscription automatique...

    Read the article

  • Turn-based Strategy Loop

    - by Djentleman
    I'm working on a strategy game. It's turn-based and card-based (think Dominion-style), done in a client, with eventual AI in the works. I've already implemented almost all of the game logic (methods for calculations and suchlike) and I'm starting to work on the actual game loop. What is the "best" way to implement a game loop in such a game? Should I use a simple "while gameActive" loop that keeps running until gameActive is False, with sections that wait for player input? Or should it be managed through the UI with player actions determining what happens and when? Any help is appreciated. I'm doing it in Python (for now at least) to get my Python skills up a bit, although the language shouldn't matter for this question.

    Read the article

  • Is there a way to use scala with html5?

    - by Maik Klein
    I want to create a very simple 2d multiplayer browsergame in html5. Something like Scalatron I mainly want to do this to improve my scala skills, the problem is I would have to code the clientside code in javascript and the serverside code in scala. This would result in duplicated code. Another option would be to ignore the html5 part and write it in opengl. But I would still prefer to have a html5 game. I could do this is in javascript, but then it would destroy the whole purpose of learning scala. Is there a way to use scala with html5? Or what would you recommend me to do?

    Read the article

  • What's the real benefit of meta-modeling?

    - by Jakob
    After reading several texts about meta-modeling I still do not really get the practical benefit. Sometimes I think it is only an interesting mind game but no useful tool. Sure it is wise to clarify your modeling vocabulary: some may say class where others say entity or concept, but this is just simple documentation your modeling terminology. Meta-modeling, as I understand it, is more complex, as it tries to formalize and abstract modeling. Some good examples are Keet's formal comparison of conceptual data modeling languages (UML, ERM and ORM) from academia and the Meta Object Facility (MOF) from industry. To me MOF looks as impractical as CORBA, which was also created by OMG. In theory you could use meta-modeling to transform and integrate models in different modeling languages, but is anyone actually doing this?

    Read the article

  • Demystified - BI in SharePoint 2010

    - by Sahil Malik
    Ad:: SharePoint 2007 Training in .NET 3.5 technologies (more information). Frequently, my clients ask me if there is a good guide on deciphering the seemingly daunting choice of products from Microsoft when it comes to business intelligence offerings in a SharePoint 2010 world. These are all described in detail in my book, but here is a one (well maybe two) page executive overview. Microsoft Excel: Yes, Microsoft Excel! Your favorite and most commonly used in the world database. No it isn’t a database in technical pure definitions, but this is the most commonly used ‘database’ in the world. You will find many business users craft up very compelling excel sheets with tonnes of logic inside them. Good for: Quick Ad-Hoc reports. Excel 64 bit allows the possibility of very large datasheets (Also see 32 bit vs 64 bit Office, and PowerPivot Add-In below). Audience: End business user can build such solutions. Related technologies: PowerPivot, Excel Services Microsoft Excel with PowerPivot Add-In: The powerpivot add-in is an extension to Excel that adds support for large-scale data. Think of this as Excel with the ability to deal with very large amounts of data. It has an in-memory data store as an option for Analysis services. Good for: Ad-hoc reporting and logic with very large amounts of data. Audience: End business user can build such solutions. Related technologies: Excel, and Excel Services Excel Services: Excel Services is a Microsoft SharePoint Server 2010 shared service that brings the power of Excel to SharePoint Server by providing server-side calculation and browser-based rendering of Excel workbooks. Thus, excel sheets can be created by end users, and published to SharePoint server – which are then rendered right through the browser in read-only or parameterized-read-only modes. They can also be accessed by other software via SOAP or REST based APIs. Good for: Sharing excel sheets with a larger number of people, while maintaining control/version control etc. Sharing logic embedded in excel sheets with other software across the organization via REST/SOAP interfaces Audience: End business users can build such solutions once your tech staff has setup excel services on a SharePoint server instance. Programmers can write software consuming functionality/complex formulae contained in your sheets. Related technologies: PerformancePoint Services, Excel, and PowerPivot. Visio Services: Visio Services is a shared service on the Microsoft SharePoint Server 2010 platform that allows users to share and view Visio diagrams that may or may not have data connected to them. Connected data can update these diagrams allowing a visual/graphical view into the data. The diagrams are viewable through the browser. They are rendered in silverlight, but will automatically down-convert to .png formats. Good for: Showing data as diagrams, live updating. Comes with a developer story. Audience: End business users can build such solutions once your tech staff has setup visio services on a SharePoint server instance. Developers can enhance the visualizations Related Technologies: Visio Services can be used to render workflow visualizations in SP2010 Reporting Services: SQL Server reporting services can integrate with SharePoint, allowing you to store reports and data sources in SharePoint document libraries, and render these reports and associated functionality such as subscriptions through a SharePoint site. In SharePoint 2010, you can also write reports against SharePoint lists (access services uses this technique). Good for: Showing complex reports running in a industry standard data store, such as SQL server. Audience: This is definitely developer land. Don’t expect end users to craft up reports, unless a report model has previously been published. Related Technologies: PerformancePoint Services PerformancePoint Services: PerformancePoint Services in SharePoint 2010 is now fully integrated with SharePoint, and comes with features that can either be used in the BI center site definition, or on their own as activated features in existing site collections. PerformancePoint services allows you to build reports and dashboards that target a variety of back-end datasources including: SQL Server reporting services, SQL Server analysis services, SharePoint lists, excel services, simple tables, etc. Using these you have the ability to create dashboards, scorecards/kpis, and simple reports. You can also create reports targeting hierarchical multidimensional data sources. The visual decomposition tree is a new report type that lets you quickly breakdown multi-dimensional data. Good for: Mostly everything :), except your wallet – it’s not free! But this is the most comprehensive offering. If you have SharePoint server, forget everything and go with performance point. Audience: Developers need to setup the back-end sources, manageability story. DBAs need to setup datawarehouses with cubes. Moderately sophisticated business users, or developers can craft up reports using dashboard designer which is a click-once App that deploys with PerformancePoint Related Technologies: Excel services, reporting services, etc.   Other relevant technologies to know about: Business Connectivity Services: Allows for consumption of external data in SharePoint as columns or external lists. This can be paired with one or more of the above BI offerings allowing insight into such data. Access Services: Allows the representation/publishing of an access database as a SharePoint 2010 site, leveraging many SharePoint features. Reporting services is used by Access services. Secure Store Service: The SP2010 Secure store service is a replacement for the SP2007 single sign on feature. This acts as a credential policeman providing credentials to various applications running with SharePoint. BCS, PerformancePoint Services, Excel Services, and many other apps use the SSS (Secure Store Service) for credential control. Comment on the article ....

    Read the article

  • Disable default error pages/error messages in IIS

    - by Antoine
    I have this web application (ASP.Net MVC 3) that on certain conditions returns a custom JSON string with a HTTP status code for an error (403, 415, 500). It is deployed on a Win 2008 R2 server with IIS 7.5 Initially I was gettting the standard HTML pages for the error instead of the JSON data. I removed the error pages for these errors in the app settings. But now my queries which should return some JSON data return a single error line. When the server gives me 403, I have the message "You do not have permission to view this directory or page." (simple line, no HTML around it). What can I do to deactivate this and finally get what the app is returning and not what the server wants to return?

    Read the article

  • DIY Door Lock Grants Access via RFID

    - by Jason Fitzpatrick
    If you’re looking to lighten the load on your pocket and banish the jingling of keys, this RFID-key hack makes your front door keycard accessible–and even supports groups and user privileges. Steve, a DIYer and Hack A Day reader, was looking for a solution to a simple problem: he wanted to easily give his friends access to his home without having to copy lots of keys and bulk up their key rings. Since all his friends already carried a Boston public transit RFID card the least intrusive solution was to hack his front door to support RFID cards. His Arduino-based solution can store up to 50 RFID card identifiers, supports group-based access, and thanks to a little laser cutting and stain the project enclosure blends in with the Victorian styling of his home’s facade. Hit up the link below to see his code–for a closer look at the actual enclosure check out this photo gallery. RFID Front Door Lock [via Hack A Day] HTG Explains: What is DNS? How To Switch Webmail Providers Without Losing All Your Email How To Force Windows Applications to Use a Specific CPU

    Read the article

  • What word processor can manage left and right pages separately?

    - by chtfn
    I was after a word processor that can manage left and right pages separately so I can have my text on the right pages and my illustrations on the left pages. I know LibeOffice can set "left page" and "right page" formats, but there is no simple way to make the text jump from right page to right page when writing. I don't know what would be the best way to do that, but I guess I need an app that is designed for writing books and do that kind of thing, or an app that can associate a page format with an object format (so the "illustration" format can be exclusively associated with "left page" format, and "text body" exclusively associated with "right page", for example). Or is there an extension for LO or OOo out there that I didn't hear about? Cheers!

    Read the article

  • Ubuntu, OpenSuse, the world of linux for a web-developer

    - by SonofWatson
    I'm learning web development. My main OS is windows 7 but I've used Linux and currently dual-booting with Ubuntu. My Linux knowledge however, is pretty limited. I can work with the command line on simple tasks but that's pretty much it. I don't do any shell scripting, don't know very well the most important commands, nor the system in general. I am interested in web development. Should I get myself familiarized more with Linux ? Is it a must for future job positions considering my field of interest?

    Read the article

  • Python library for scripting (C++ integration)

    - by Edward83
    Please advise me good wrapper/library for python. I need to implement simple scripting in c++ app; Under "good" I mean pretty understandable, well documented, no memory leaking, fast. For creating base interface of GameObject on Python and C++; Your own experience and useful links will be nice!!! I found link about it, but I need more specific within gamedev context. What combinations of libraries you used for python integration into c++? For example about ogre-python it said built using Py++ and Boost.Python library And one more question, maybe someone of you know how Python was integrated into BigWorld engine (it's own port or some library)? Thank you!!!

    Read the article

  • Estudio de caso: CFO de At&T le apunta a la tecnología para transformar las Finanzas Globales

    - by RED League Heroes-Oracle
    AT&T es una de las pocas multinacionales modernas que han participado de todas las etapas anteriores de la innovación de las telecomunicaciones, de Alexander Graham Bell como inventor solitario, a Bell Labs, a los lanzamientos acelerados en las fundiciones de AT&T. La tecnología es el corazón de todo lo que AT&T hace, incluyendo sus inversiones en innovaciones tecnológicas para permitir que las finanzas de AT&T trabajen más estratégicamente con los negocios para asegurar que las inversiones en las iniciativas de crecimiento sean exitosas. Según John Stephens, Vicepresidente Ejecutivo y director financiero de AT&T, la empresa ha trazado un plan de inversión de tres años para mejorar y aumentar sus redes IP de banda ancha alámbricas e inalámbricas. El plan incluye la implementación del servicio 4G LTE para 300 millones de personas en los Estados Unidos, expansión de IP de banda ancha de alta velocidad a unos 57 millones de hogares de clientes y una expansión de la fibra a 1 millón de clientes corporativos adicionales en su área de servicio de telefonía fija. "La necesidad de velocidad es mayor que nunca, y este proyecto es nuestro paso hacia la innovación para ofrecer tal velocidad," dice Stephens. Como AT&T moderniza su infraestructura global, sus procesos operacionales se hacen tan poderosos como su red. Ha sido una tarea grande y compleja, pero Stephens se complace al decir que el departamento de finanzas de AT&T ha adoptado su papel de catalizador corporativo. Empezó con un concepto simple: "Vamos a hacer que todos hablen en el mismo idioma". Esto llevó a la consolidación de sistemas financieros heredados de las empresas adquiridas. No fue una tarea sencilla, dado que la empresa pasó por más de cinco adquisiciones importantes y un sinfín de otras transacciones. En 2007, AT&T tenía 17 aplicaciones apenas en la función de cuentas por pagar. Hoy, el número se ha reducido a dos. Asimismo, hubo 50 sistemas de reportes gerenciales oficiales y ahora hay tres, con planes de excluir uno de ellos. Al tener un único lenguaje volcado a las Finanzas en toda la empresa, el equipo de finanzas de AT&T ha eliminado las varias versiones de los mismos datos, reduciendo la posible confusión en las discusiones y en las decisiones de estrategia de negocios. Estos pasos también han reducido los costos y aceleraron la toma de decisiones. "Lo lindo de los sistemas es que permiten que la gente talentosa con habilidades analíticas usen su tiempo en esa zona, en vez de gastar tiempo en recolección, agregación y organización de los datos," señala Stephens. "Tenemos un proceso eficiente y eficaz que hace que nosotros, dejemos a la gente libre para dedicarse a aquello en que son realmente buenos. Y tenemos un equipo de alta calidad y ellos están en su mejor punto cuando son capaces de hacer su función para apoyar a la unidad de negocio”AT&T es una de las pocas multinacionales modernas que han participado de todas las etapas anteriores de la innovación de las telecomunicaciones, de Alexander Graham Bell como inventor solitario, a Bell Labs, a los lanzamientos acelerados en las fundiciones de AT&T. La tecnología es el corazón de todo lo que AT&T hace, incluyendo sus inversiones en innovaciones tecnológicas para permitir que las finanzas de AT&T trabajen más estratégicamente con los negocios para asegurar que las inversiones en las iniciativas de crecimiento sean exitosas.  Según John Stephens, Vicepresidente Ejecutivo y director financiero de AT&T, la empresa ha trazado un plan de inversión de tres años para mejorar y aumentar sus redes IP de banda ancha alámbricas e inalámbricas. El plan incluye la implementación del servicio 4G LTE para 300 millones de personas en los Estados Unidos, expansión de IP de banda ancha de alta velocidad a unos 57 millones de hogares de clientes y una expansión de la fibra a 1 millón de clientes corporativos adicionales en su área de servicio de telefonía fija. "La necesidad de velocidad es mayor que nunca, y este proyecto es nuestro paso hacia la innovación para ofrecer tal velocidad," dice Stephens. Como AT&T moderniza su infraestructura global, sus procesos operacionales se hacen tan poderosos como su red. Ha sido una tarea grande y compleja, pero Stephens se complace al decir que el departamento de finanzas de AT&T ha adoptado su papel de catalizador corporativo. Empezó con un concepto simple: "Vamos a hacer que todos hablen en el mismo idioma". Esto llevó a la consolidación de sistemas financieros heredados de las empresas adquiridas. No fue una tarea sencilla, dado que la empresa pasó por más de cinco adquisiciones importantes y un sinfín de otras transacciones. En 2007, AT&T tenía 17 aplicaciones apenas en la función de cuentas por pagar. Hoy, el número se ha reducido a dos. Asimismo, hubo 50 sistemas de reportes gerenciales oficiales y ahora hay tres, con planes de excluir uno de ellos. Al tener un único lenguaje volcado a las Finanzas en toda la empresa, el equipo de finanzas de AT&T ha eliminado las varias versiones de los mismos datos, reduciendo la posible confusión en las discusiones y en las decisiones de estrategia de negocios. Estos pasos también han reducido los costos y aceleraron la toma de decisiones. "Lo lindo de los sistemas es que permiten que la gente talentosa con habilidades analíticas usen su tiempo en esa zona, en vez de gastar tiempo en recolección, agregación y organización de los datos," señala Stephens. "Tenemos un proceso eficiente y eficaz que hace que nosotros, dejemos a la gente libre para dedicarse a aquello en que son realmente buenos. Y tenemos un equipo de alta calidad y ellos están en su mejor punto cuando son capaces de hacer su función para apoyar a la unidad de negocio”

    Read the article

  • how to learn ios game development using swift.. good starting point?

    - by hamobi
    I've published a simple app on the app store using objective-c. That was a good learning experience but I never grew to love the language. Later on I jumped into learning cocos2d in order to begin developing a game.. but objective-c always seemed really cumbersome to write. Eventually I put my project aside. Now that swift has come out.. It has made me think about developing games again.. I know that xcode has some project types geared towards game development, but since I'm a beginner in this area I really need some hand holding (books / tutorials) to get started. Cocos2d seems like its really stuck in that objective-c world. What's the best way for a beginner to learn game development using swift?

    Read the article

  • Second display running off laptop VGA not correctly positioned (offset left and up)

    - by Filthy Pazuzu
    I have black bars on the right and bottom of my display! I'm running my laptop's VGA output to an recognized as a It is 20", but the assumed 3" difference does not account for the incorrect position. Everything displays fine. It runs high-res video beautifully. But it's 3/4" offset left and an unreasonably annoying 1/4" offset up. I've tried going through the display's annoying & useless menu, but it doesn't have any way to adjust the position. I'm certainly no linux newbie, but on this Ubuntu (Pangolin, BTW) I can't figure out how to make simple positional display changes on Ubuntu. It's not only frustrating, it's a bit humiliating! So. Does anyone know of an app that will allow me to make basic display position alterations? ("App" - annoyingly trendy, but a useful word - no matter how grating.) Thanks, & Cheers, Paz

    Read the article

  • Obsolete Computer Parts as Art [DIY]

    - by Jason Fitzpatrick
    If you’re like most geeks, you’ve got a box of aging computer equipment you just haven’t got around to hauling to your city’s haz-mat drop off site. This simple tutorial turns cast off circuit boards into wall art. While the author of the tutorial opted to use motherboards, you could easily use smaller frames/mats and use old expansion boards too. The process involves inexpensive IKEA frames with mats, popping the I/O ports off the boards to make them thinner, and drilling small mount holes in the backer board to mount the boards in place. Hit up the link below for more details. Motherboard Art [via IKEAHackers] How to Use an Xbox 360 Controller On Your Windows PC Download the Official How-To Geek Trivia App for Windows 8 How to Banish Duplicate Photos with VisiPic

    Read the article

  • Pass FORTRAN variable to Python [migrated]

    - by Matthew Bilskie
    I have a FORTRAN program that is called from a Python script (as an ArcGIS tool). I need to pass an array, Raster_Z(i,j), from FORTRAN to python. I have read about the Python subprocess module; however, I have not had much luck in understanding how to do this with FORTRAN. All examples I have found involve simple unix command line calls and not actual programs. Has anyone had any experience in passing a variable from FORTRAN to Python via a memory PIPE? Thank you for your time.

    Read the article

  • Game Maker Studio Gravity Problems

    - by Dusty
    I've started messing around with Game Maker Studio. The problem I'm having is trying to get a gravity code for orbiting. Here's how i did it in XNA foreach (GravItem Item in StarSystem.ActiveItems.OfType<GravItem>()) { if (this != Item) { Velocity += (10 * Vector2.Normalize(Item.Position - this.Position * (this.Mass * Item.Mass) / (Vector2.DistanceSquared(this.Position, Item.Position)) / (this.Mass)); } } Simple and works well, things or bit and everything is nice. but in Game maker i don't have the luxury of Vector2's or a For-each loop to loop threw all the objects that have a mass. I've tried a few different things but nothing seems to work distance = distance_to_object(obj_moon); //--Gravity hspeed += (0.5 * (distance) * (Mass * obj_moon.Mass) / (sqr(distance)) / Mass) vspeed += (0.5 * (distance) * (Mass * obj_moon.Mass) / (sqr(distance)) / Mass) thanks for the help

    Read the article

< Previous Page | 307 308 309 310 311 312 313 314 315 316 317 318  | Next Page >