Search Results

Search found 1897 results on 76 pages for 'beat detection'.

Page 50/76 | < Previous Page | 46 47 48 49 50 51 52 53 54 55 56 57  | Next Page >

  • Determining if two lines intersect

    - by Faken
    I have two lines that extend to infinity but both have a starting point. They are both described by a starting point and a vector in the direction of the line extending to infinity. I want to find out if the two lines intersect but i don't need to know where they intersect (its part of a collision detection algorithm). Everything i have looked at so far describes finding the intersection point of two lines or line segments. Anyone know a fast algorithm to solve this?

    Read the article

  • OpenCV haar training for static image

    - by Evl-ntnt
    I trying to train haar cascade classificator for card suite detection (which no rotation and has no distortion on image) For example I have file Clubs.png which contents clubs image on white background 20x20 pixels This tutorial is so tangled http://note.sonots.com/SciSoftware/haartraining.html My image varies only in sizes, no distortion or angling. Which commands I must enter in aim to get Clubs.xml file?

    Read the article

  • Nagios notifications definitions

    - by Colin
    I am trying to monitor a web server in such a way that I want to search for a particular string on a page via http. The command is defined in command.cfg as follows # 'check_http-mysite command definition' define command { command_name check_http-mysite command_line /usr/lib/nagios/plugins/check_http -H mysite.example.com -s "Some text" } # 'notify-host-by-sms' command definition define command { command_name notify-host-by-sms command_line /usr/bin/send_sms $CONTACTPAGER$ "Nagios - $NOTIFICATIONTYPE$ :Host$HOSTALIAS$ is $HOSTSTATE$ ($OUTPUT$)" } # 'notify-service-by-sms' command definition define command { command_name notify-service-by-sms command_line /usr/bin/send_sms $CONTACTPAGER$ "Nagios - $NOTIFICATIONTYPE$: $HOSTALIAS$/$SERVICEDESC$ is $SERVICESTATE$ ($OUTPUT$)" } Now if nagios doesn't find "Some text" on the home page mysite.example.com, nagios should notify a contact via sms through the Clickatell http API which I have a script for that that I have tested and found that it works fine. Whenever I change the command definition to search for a string which is not on the page, and restart nagios, I can see on the web interface that the string was not found. What I don't understand is why isn't the notification sent though I have defined the host, hostgroup, contact, contactgroup and service and so forth. What I'm I missing, these are my definitions, In my web access through the cgi I can see that I have notifications have been defined and enabled though I don't get both email and sms notifications during hard status changes. host.cfg define host { use generic-host host_name HAL alias IBM-1 address xxx.xxx.xxx.xxx check_command check_http-mysite } *hostgroups_nagios2.cfg* # my website define hostgroup{ hostgroup_name my-servers alias All My Servers members HAL } *contacts_nagios2.cfg* define contact { contact_name colin alias Colin Y service_notification_period 24x7 host_notification_period 24x7 service_notification_options w,u,c,r,f,s host_notification_options d,u,r,f,s service_notification_commands notify-service-by-email,notify-service-by-sms host_notification_commands notify-host-by-email,notify-host-by-sms email [email protected] pager +254xxxxxxxxx } define contactgroup{ contactgroup_name site_admin alias Site Administrator members colin } *services_nagios2.cfg* # check for particular string in page via http define service { hostgroup_name my-servers service_description STRING CHECK check_command check_http-mysite use generic-service notification_interval 0 ; set > 0 if you want to be renotified contacts colin contact_groups site_admin } Could someone please tell me where I'm going wrong. Here are the generic-host and generic-service definitions *generic-service_nagios2.cfg* # generic service template definition define service{ name generic-service ; The 'name' of this service template active_checks_enabled 1 ; Active service checks are enabled passive_checks_enabled 1 ; Passive service checks are enabled/accepted parallelize_check 1 ; Active service checks should be parallelized (disabling this can lead to major performance problems) obsess_over_service 1 ; We should obsess over this service (if necessary) check_freshness 0 ; Default is to NOT check service 'freshness' notifications_enabled 1 ; Service notifications are enabled event_handler_enabled 1 ; Service event handler is enabled flap_detection_enabled 1 ; Flap detection is enabled failure_prediction_enabled 1 ; Failure prediction is enabled process_perf_data 1 ; Process performance data retain_status_information 1 ; Retain status information across program restarts retain_nonstatus_information 1 ; Retain non-status information across program restarts notification_interval 0 ; Only send notifications on status change by default. is_volatile 0 check_period 24x7 normal_check_interval 5 retry_check_interval 1 max_check_attempts 4 notification_period 24x7 notification_options w,u,c,r contact_groups site_admin register 0 ; DONT REGISTER THIS DEFINITION - ITS NOT A REAL SERVICE, JUST A TEMPLATE! } *generic-host_nagios2.cfg* define host{ name generic-host ; The name of this host template notifications_enabled 1 ; Host notifications are enabled event_handler_enabled 1 ; Host event handler is enabled flap_detection_enabled 1 ; Flap detection is enabled failure_prediction_enabled 1 ; Failure prediction is enabled process_perf_data 1 ; Process performance data retain_status_information 1 ; Retain status information across program restarts retain_nonstatus_information 1 ; Retain non-status information across program restarts max_check_attempts 10 notification_interval 0 notification_period 24x7 notification_options d,u,r contact_groups site_admin register 1 ; DONT REGISTER THIS DEFINITION - ITS NOT A REAL HOST, JUST A TEMPLATE! }

    Read the article

  • Thank You for a Great Welcome for Oracle GoldenGate 11g Release 2

    - by Irem Radzik
    Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:Calibri; mso-fareast-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Yesterday morning we had two launch webcasts for Oracle GoldenGate 11g Release 2. I had the pleasure to present, as well as moderate the Q&A panels in both of these webcasts. Both events had hundreds of live attendees, sending us over 150 questions. Even though we left 30 minutes for Q&A, it was not nearly enough time to address for all the insightful questions our audience sent. Our product management team and I really appreciate the interaction we had yesterday and we are starting to respond back with outstanding questions today. Oracle GoldenGate’s new release launch also had great welcome from the media. You can find the links for various articles on the new release below: ITBusinessEdge Oracle Embraces Cross-Platform Data Integration Information Week: Oracle Real-Time Advance Taps Compressed Data Integration Developer News, Oracle GoldenGate Adds Deeper Oracle Integration, Extends Real-Time Performance CIO, Oracle GoldenGate Buddies Up with Sibling Software DBTA, Real-Time Data Integration: Oracle GoldenGate 11g Release 2 Now Available CBR Oracle unveils GoldenGate 11g Release 2 real-time data integration application In this blog, I want to address some of the frequently asked questions that came up during the webcasts. You can find the top questions and their answers along with related resources below. We will continue to address frequently asked questions via future blogs. Q: Will the new Integrated Capture for Oracle Database replace the Classic Capture? If not, which one do I use when? A: No, Classic Capture will be around for long time. Core platform specific features, bug fixes, and patches will be available for both Capture processes.Oracle Database specific features will be only available in the Integrated Capture. The Integrated Capture for Oracle Database is an option for users that need to capture data from compressed tables or need support for XML data types, XA on RAC. Users who don’t leverage these features should continue to use our Classic Capture. For more information on Oracle GoldenGate 11g Release 2 I recommend to check out the White paper: Oracle GoldenGate 11gR2 New Features as well as other technical white papers we have on OTN.                                                         For those of you coming to OpenWorld, please attend the related session: Extracting Data in Oracle GoldenGate Integrated Capture Mode, Monday Oct 1st 1:45pm Moscone South – 102 to learn more about this new feature. Q: What is new in Conflict Detection and Resolution? And how does it work? A: There are now pre-built functions to identify the conditions under which an error occurs and how to handle the record when the condition occurs. Error conditions handled include inserts into a target table where the row already exists, updates or deletes to target table rows that exist, but the original source data (before columns) do not match the existing data in the target row, and updates or deletes where the row does not exist in the target database table.Foreach of these conditions a method to handle the error is specified.  Please check out our recent blog on this topic and the White paper: Oracle GoldenGate 11gR2 New Features white paper.  Also, for those attending OpenWorld please attend the session: Best Practices for Conflict Detection and Resolution in Oracle GoldenGate for Active/Active-  Wednesday Oct 3rd  3:30pm Mascone 3000 Q: Does Oracle GoldenGate Veridata and the Management Pack require additional licenses, or is it incorporated with the GoldenGate license? A: Oracle GoldenGate Veridata and Oracle Management Pack for Oracle GoldenGate are additional products and require separate licenses. Please check out Oracle's price list here. Q: Does GoldenGate - Oracle Enterprise Manager Plug-in require additional license? A: Oracle Enterprise Manager Plug-in is included in the Oracle Management Pack for Oracle GoldenGate license, which is separate from Oracle GoldenGate license. There is no separate license for the Enterprise Manager Plug-in by itself. Oracle GoldenGate Monitor, Oracle GoldenGate Director, and Enterprise Manager Plug-in are included in the Management Pack for Oracle GoldenGate license. Please check out Management Pack for Oracle GoldenGate data sheet for more info on this product bundle. Q: Is Oracle GoldenGate replacing Oracle Streams product? A: Oracle GoldenGate is the strategic data replication product. Therefore, Oracle Streams will continue to be supported, but will not be actively enhanced. Rather, the best elements of Oracle Streams will be added to Oracle GoldenGate. Conflict management is one of them and with the latest release Oracle GoldenGate has a more advanced conflict management offering. Current customers depending on Oracle Streams will continue to be fully supported. Q: How is Oracle GoldenGate different than Oracle Data Integrator? A: Oracle Data Integrator is designed for fast bulk data movement and transformation between heterogeneous systems, while GoldenGate is designed for real-time movement of transactions between heterogeneous systems. These two products are completely complementary where GoldenGate provides low-impact real-time change data capture and delivery to a staging area on the target. And Oracle Data Integrator transforms this data and loads the DW tables. In fact, Oracle Data Integrator integrates with GoldenGate to use GoldenGate’s Capture process as one option for its CDC mechanism. We have several customers that deployed GoldenGate and ODI together to feed real-time data to their data warehousing solutions. Please also check out Oracle Data Integrator Changed Data Capture with Oracle GoldenGate Data Sheet (PDF). Thank you again very much for welcoming Oracle GoldenGate 11g Release 2 and stay in touch with us for more exciting news, updates, and events.

    Read the article

  • Another Marketing Conference, part one – the best morning sessions.

    - by Roger Hart
    Yesterday I went to Another Marketing Conference. I honestly can’t tell if the title is just tipping over into smug, but in the balance of things that doesn’t matter, because it was a good conference. There was an enjoyable blend of theoretical and practical, and enough inter-disciplinary spread to keep my inner dilettante grinning from ear to ear. Sure, there was a bumpy bit in the middle, with two back-to-back sales pitches and a rather thin overview of the state of the web. But the signal:noise ratio at AMC2012 was impressively high. Here’s the first part of my write-up of the sessions. It’s a bit of a mammoth. It’s also a bit of a mash-up of what was said and what I thought about it. I’ll add links to the videos and slides from the sessions as they become available. Although it was in the morning session, I’ve not included Vanessa Northam’s session on the power of internal comms to build brand ambassadors. It’ll be in the next roundup, as this is already pushing 2.5k words. First, the important stuff. I was keeping a tally, and nobody said “synergy” or “leverage”. I did, however, hear the term “marketeers” six times. Shame on you – you know who you are. 1 – Branding in a post-digital world, Graham Hales This initially looked like being a sales presentation for Interbrand, but Graham pulled it out of the bag a few minutes in. He introduced a model for brand management that was essentially Plan >> Do >> Check >> Act, with Do and Check rolled up together, and went on to stress that this looks like on overall business management model for a reason. Brand has to be part of your overall business strategy and metrics if you’re going to care about it at all. This was the first iteration of what proved to be one of the event’s emergent themes: do it throughout the stack or don’t bother. Graham went on to remind us that brands, in so far as they are owned at all, are owned by and co-created with our customers. Advertising can offer a message to customers, but they provide the expression of a brand. This was a preface to talking about an increasingly chaotic marketplace, with increasingly hard-to-manage purchase processes. Services like Amazon reviews and TripAdvisor (four presenters would make this point) saturate customers with information, and give them a kind of vigilante power to comment on and define brands. Consequentially, they experience a number of “moments of deflection” in our sales funnels. Our control is lessened, and failure to engage can negatively-impact buying decisions increasingly poorly. The clearest example given was the failure of NatWest’s “caring bank” campaign, where staff in branches, customer support, and online presences didn’t align. A discontinuity of experience basically made the campaign worthless, and disgruntled customers talked about it loudly on social media. This in turn presented an opportunity to engage and show caring, but that wasn’t taken. What I took away was that brand (co)creation is ongoing and needs monitoring and metrics. But reciprocally, given you get what you measure, strategy and metrics must include brand if any kind of branding is to work at all. Campaigns and messages must permeate product and service design. What that doesn’t mean (and Graham didn’t say it did) is putting Marketing at the top of the pyramid, and having them bawl demands at Product Management, Support, and Development like an entitled toddler. It’s going to have to be collaborative, and session 6 on internal comms handled this really well. The main thing missing here was substantiating data, and the main question I found myself chewing on was: if we’re building brands collaboratively and in the open, what about the cultural politics of trolling? 2 – Challenging our core beliefs about human behaviour, Mark Earls This was definitely the best show of the day. It was also some of the best content. Mark talked us through nudging, behavioural economics, and some key misconceptions around decision making. Basically, people aren’t rational, they’re petty, reactive, emotional sacks of meat, and they’ll go where they’re led. Comforting stuff. Examples given were the spread of the London Riots and the “discovery” of the mountains of Kong, and the popularity of Susan Boyle, which, in turn made me think about Per Mollerup’s concept of “social wayshowing”. Mark boiled his thoughts down into four key points which I completely failed to write down word for word: People do, then think – Changing minds to change behaviour doesn’t work. Post-rationalization rules the day. See also: mere exposure effects. Spock < Kirk - Emotional/intuitive comes first, then we rationalize impulses. The non-thinking, emotive, reactive processes run much faster than the deliberative ones. People are not really rational decision makers, so  intervening with information may not be appropriate. Maximisers or satisficers? – Related to the last point. People do not consistently, rationally, maximise. When faced with an abundance of choice, they prefer to satisfice than evaluate, and will often follow social leads rather than think. Things tend to converge – Behaviour trends to a consensus normal. When faced with choices people overwhelmingly just do what they see others doing. Humans are extraordinarily good at mirroring behaviours and receiving influence. People “outsource the cognitive load” of choices to the crowd. Mark’s headline quote was probably “the real influence happens at the table next to you”. Reference examples, word of mouth, and social influence are tremendously important, and so talking about product experiences may be more important than talking about products. This reminded me of Kathy Sierra’s “creating bad-ass users” concept of designing to make people more awesome rather than products they like. If we can expose user-awesome, and make sharing easy, we can normalise the behaviours we want. If we normalize the behaviours we want, people should make and post-rationalize the buying decisions we want.  Where we need to be: “A bigger boy made me do it” Where we are: “a wizard did it and ran away” However, it’s worth bearing in mind that some purchasing decisions are personal and informed rather than social and reactive. There’s a quadrant diagram, in fact. What was really interesting, though, towards the end of the talk, was some advice for working out how social your products might be. The standard technology adoption lifecycle graph is essentially about social product diffusion. So this idea isn’t really new. Geoffrey Moore’s “chasm” idea may not strictly apply. However, his concepts of beachheads and reference segments are exactly what is required to normalize and thus enable purchase decisions (behaviour change). The final thing is that in only very few categories does a better product actually affect purchase decision. Where the choice is personal and informed, this is true. But where it’s personal and impulsive, or in any way social, “better” is trumped by popularity, endorsement, or “point of sale salience”. UX, UCD, and e-commerce know this to be true. A better (and easier) experience will always beat “more features”. Easy to use, and easy to observe being used will beat “what the user says they want”. This made me think about the astounding stickiness of rational fallacies, “common sense” and the pathological willful simplifications of the media. Rational fallacies seem like they’re basically the heuristics we use for post-rationalization. If I were profoundly grimy and cynical, I’d suggest deploying a boat-load in our messaging, to see if they’re really as sticky and appealing as they look. 4 – Changing behaviour through communication, Stephen Donajgrodzki This was a fantastic follow up to Mark’s session. Stephen basically talked us through some tactics used in public information/health comms that implement the kind of behavioural theory Mark introduced. The session was largely about how to get people to do (good) things they’re predisposed not to do, and how communication can (and can’t) make positive interventions. A couple of things stood out, in particular “implementation intentions” and how they can be linked to goals. For example, in order to get people to check and test their smoke alarms (a goal intention, rarely actualized  an information campaign will attempt to link this activity to the clocks going back or forward (a strong implementation intention, well-actualized). The talk reinforced the idea that making behaviour changes easy and visible normalizes them and makes them more likely to succeed. To do this, they have to be embodied throughout a product and service cycle. Experiential disconnects undermine the normalization. So campaigns, products, and customer interactions must be aligned. This is underscored by the second section of the presentation, which talked about interventions and pre-conditions for change. Taking the examples of drug addiction and stopping smoking, Stephen showed us a framework for attempting (and succeeding or failing in) behaviour change. He noted that when the change is something people fundamentally want to do, and that is easy, this gets a to simpler. Coordinated, easily-observed environmental pressures create preconditions for change and build motivation. (price, pub smoking ban, ad campaigns, friend quitting, declining social acceptability) A triggering even leads to a change attempt. (getting a cold and panicking about how bad the cough is) Interventions can be made to enable an attempt (NHS services, public information, nicotine patches) If it succeeds – yay. If it fails, there’s strong negative enforcement. Triggering events seem largely personal, but messaging can intervene in the creation of preconditions and in supporting decisions. Stephen talked more about systems of thinking and “bounded rationality”. The idea being that to enable change you need to break through “automatic” thinking into “reflective” thinking. Disruption and emotion are great tools for this, but that is only the start of the process. It occurs to me that a great deal of market research is focused on determining triggers rather than analysing necessary preconditions. Although they are presumably related. The final section talked about setting goals. Marketing goals are often seen as deriving directly from business goals. However, marketing may be unable to deliver on these directly where decision and behaviour-change processes are involved. In those cases, marketing and communication goals should be to create preconditions. They should also consider priming and norms. Content marketing and brand awareness are good first steps here, as brands can be heuristics in decision making for choice-saturated consumers, or those seeking education. 5 – The power of engaged communities and how to build them, Harriet Minter (the Guardian) The meat of this was that you need to let communities define and establish themselves, and be quick to react to their needs. Harriet had been in charge of building the Guardian’s community sites, and learned a lot about how they come together, stabilize  grow, and react. Crucially, they can’t be about sales or push messaging. A community is not just an audience. It’s essential to start with what this particular segment or tribe are interested in, then what they want to hear. Eventually you can consider – in light of this – what they might want to buy, but you can’t start with the product. A community won’t cohere around one you’re pushing. Her tips for community building were (again, sorry, not verbatim): Set goals Have some targets. Community building sounds vague and fluffy, but you can have (and adjust) concrete goals. Think like a start-up This is the “lean” stuff. Try things, fail quickly, respond. Don’t restrict platforms Let the audience choose them, and be aware of their differences. For example, LinkedIn is very different to Twitter. Track your stats Related to the first point. Keeping an eye on the numbers lets you respond. They should be qualified, however. If you want a community of enterprise decision makers, headcount alone may be a bad metric – have you got CIOs, or just people who want to get jobs by mingling with CIOs? Build brand advocates Do things to involve people and make them awesome, and they’ll cheer-lead for you. The last part really got my attention. Little bits of drive-by kindness go a long way. But more than that, genuinely helping people turns them into powerful advocates. Harriet gave an example of the Guardian engaging with an aspiring journalist on its Q&A forums. Through a series of serendipitous encounters he became a BBC producer, and now enthusiastically speaks up for the Guardian community sites. Cultivating many small, authentic, influential voices may have a better pay-off than schmoozing the big guys. This could be particularly important in the context of Mark and Stephen’s models of social, endorsement-led, and example-led decision making. There’s a lot here I haven’t covered, and it may be worth some follow-up on community building. Thoughts I was quite sceptical of nudge theory and behavioural economics. First off it sounds too good to be true, and second it sounds too sinister to permit. But I haven’t done the background reading. So I’m going to, and if it seems to hold real water, and if it’s possible to do it ethically (Stephen’s presentations suggests it may be) then it’s probably worth exploring. The message seemed to be: change what people do, and they’ll work out why afterwards. Moreover, the people around them will do it too. Make the things you want them to do extraordinarily easy and very, very visible. Normalize and support the decisions you want them to make, and they’ll make them. In practice this means not talking about the thing, but showing the user-awesome. Glib? Perhaps. But it feels worth considering. Also, if I ever run a marketing conference, I’m going to ban speakers from using examples from Apple. Quite apart from not being consistently generalizable, it’s becoming an irritating cliché.

    Read the article

  • Movement prediction for non-shooters

    - by ShadowChaser
    I'm working on an isometric 2D game with moderate-scale multiplayer, approximately 20-30 players connected at once to a persistent server. I've had some difficulty getting a good movement prediction implementation in place. Physics/Movement The game doesn't have a true physics implementation, but uses the basic principles to implement movement. Rather than continually polling input, state changes (ie/ mouse down/up/move events) are used to change the state of the character entity the player is controlling. The player's direction (ie/ north-east) is combined with a constant speed and turned into a true 3D vector - the entity's velocity. In the main game loop, "Update" is called before "Draw". The update logic triggers a "physics update task" that tracks all entities with a non-zero velocity uses very basic integration to change the entities position. For example: entity.Position += entity.Velocity.Scale(ElapsedTime.Seconds) (where "Seconds" is a floating point value, but the same approach would work for millisecond integer values). The key point is that no interpolation is used for movement - the rudimentary physics engine has no concept of a "previous state" or "current state", only a position and velocity. State Change and Update Packets When the velocity of the character entity the player is controlling changes, a "move avatar" packet is sent to the server containing the entity's action type (stand, walk, run), direction (north-east), and current position. This is different from how 3D first person games work. In a 3D game the velocity (direction) can change frame to frame as the player moves around. Sending every state change would effectively transmit a packet per frame, which would be too expensive. Instead, 3D games seem to ignore state changes and send "state update" packets on a fixed interval - say, every 80-150ms. Since speed and direction updates occur much less frequently in my game, I can get away with sending every state change. Although all of the physics simulations occur at the same speed and are deterministic, latency is still an issue. For that reason, I send out routine position update packets (similar to a 3D game) but much less frequently - right now every 250ms, but I suspect with good prediction I can easily boost it towards 500ms. The biggest problem is that I've now deviated from the norm - all other documentation, guides, and samples online send routine updates and interpolate between the two states. It seems incompatible with my architecture, and I need to come up with a better movement prediction algorithm that is closer to a (very basic) "networked physics" architecture. The server then receives the packet and determines the players speed from it's movement type based on a script (Is the player able to run? Get the player's running speed). Once it has the speed, it combines it with the direction to get a vector - the entity's velocity. Some cheat detection and basic validation occurs, and the entity on the server side is updated with the current velocity, direction, and position. Basic throttling is also performed to prevent players from flooding the server with movement requests. After updating its own entity, the server broadcasts an "avatar position update" packet to all other players within range. The position update packet is used to update the client side physics simulations (world state) of the remote clients and perform prediction and lag compensation. Prediction and Lag Compensation As mentioned above, clients are authoritative for their own position. Except in cases of cheating or anomalies, the client's avatar will never be repositioned by the server. No extrapolation ("move now and correct later") is required for the client's avatar - what the player sees is correct. However, some sort of extrapolation or interpolation is required for all remote entities that are moving. Some sort of prediction and/or lag-compensation is clearly required within the client's local simulation / physics engine. Problems I've been struggling with various algorithms, and have a number of questions and problems: Should I be extrapolating, interpolating, or both? My "gut feeling" is that I should be using pure extrapolation based on velocity. State change is received by the client, client computes a "predicted" velocity that compensates for lag, and the regular physics system does the rest. However, it feels at odds to all other sample code and articles - they all seem to store a number of states and perform interpolation without a physics engine. When a packet arrives, I've tried interpolating the packet's position with the packet's velocity over a fixed time period (say, 200ms). I then take the difference between the interpolated position and the current "error" position to compute a new vector and place that on the entity instead of the velocity that was sent. However, the assumption is that another packet will arrive in that time interval, and it's incredibly difficult to "guess" when the next packet will arrive - especially since they don't all arrive on fixed intervals (ie/ state changes as well). Is the concept fundamentally flawed, or is it correct but needs some fixes / adjustments? What happens when a remote player stops? I can immediately stop the entity, but it will be positioned in the "wrong" spot until it moves again. If I estimate a vector or try to interpolate, I have an issue because I don't store the previous state - the physics engine has no way to say "you need to stop after you reach position X". It simply understands a velocity, nothing more complex. I'm reluctant to add the "packet movement state" information to the entities or physics engine, since it violates basic design principles and bleeds network code across the rest of the game engine. What should happen when entities collide? There are three scenarios - the controlling player collides locally, two entities collide on the server during a position update, or a remote entity update collides on the local client. In all cases I'm uncertain how to handle the collision - aside from cheating, both states are "correct" but at different time periods. In the case of a remote entity it doesn't make sense to draw it walking through a wall, so I perform collision detection on the local client and cause it to "stop". Based on point #2 above, I might compute a "corrected vector" that continually tries to move the entity "through the wall" which will never succeed - the remote avatar is stuck there until the error gets too high and it "snaps" into position. How do games work around this?

    Read the article

  • Regex to match the first file in a rar archive file set in Python

    - by mridang
    I need to uncompress all the files in a directory and for this I need to find the first file in the set. I'm currently doing this using a bunch of if statements and loops. Can i do this this using regex? Here's a list of files that i need to match: yes.rar yes.part1.rar yes.part01.rar yes.part001.rar yes.r01 yes.r001 These should NOT be matched: no.part2.rar no.part02.rar no.part002.rar no.part011.rar no.r002 no.r02 I found a similar regex on this thread but it seems that Python doesn't support varible length lookarounds. A single line regex would be complicated but I'll document it well and it's not a problem. It's just one of those problems you beat your heap up, over. Thanks in advance guys. :)

    Read the article

  • String comparison with a collation in javascript

    - by fsb
    I use jquery.autocomplete, which uses a javascript regexp to highlight substrings in the list of suggestions that match the autocomplete key string. So if the use types "Beat" and one of the autocomplete suggestions the server returns is "The Beatles" then plugin displays that suggestion as "The Beatles". I'm trying to think of ways to make this work with string matching that isn't sensitive to accents, diacriticals and the rest. So if the user typed "Huske" and the server suggested "Hüsker Dü" then this would be displayed as "Hüsker Dü". The principle is the same as string comparison with specified collations such as in MySql or ICU, or with Oracle's sorts. In SphinxSearch a charset_table works for this. A collation such as utf8_general_ci would be ideal for my purposes.

    Read the article

  • How do I include 2 tables in LocalStorage?

    - by Noor
    I've got a table that you can edit, and I've got a simple code saving that list when you're done with editing it. (the tables have the contenteditable on) The problem I've stumbled upon is that if I double click on enter, the table gets divided into two separate tables with the same ID. This causes the code I'm using to set the localStorage to only store one of the tables (I assume the first).. I've thought of different solutions and I wonder if someone could point out the pro's and con's (if the solutions even works that is). Make a loop that checks the page after tables and stores them into an array of localStorage-items.. I'd have to dynamically create a localStorage item for each table. Take the whole div that the tables are in, and store that in the localStorage, when a user revisits the page, the page checks after the items in storage and displays the whole divs. Any suggestions you have that can beat this :).. (but no cache, it has to be with the localStorage!) Thanks

    Read the article

  • chess AI for GAE

    - by Richard
    I am looking for a Chess AI that can be run on Google App Engine. Most chess AI's seem to be written in C and so can not be run on the GAE. It needs to be strong enough to beat a casual player, but efficient enough that it can calculate a move within a single request (less than 10 secs). Ideally it would be written in Python for easier integration with existing code. I came across a few promising projects but they don't look mature: http://code.google.com/p/chess-free http://mariobalibrera.com/mics/ai.html

    Read the article

  • Does a version control database storage engine exist?

    - by Zak
    I was just wondering if a storage engine type existed that allowed you to do version control on row level contents. For instance, if I have a simple table with ID, name, value, and ID is the PK, I could see that row 354 started as (354, "zak", "test")v1 then was updated to be (354, "zak", "this is version 2 of the value")v2 , and could see a change history on the row with something like select history (value) where ID = 354. It's kind of an esoteric thing, but it would beat having to keep writing these separate history tables and functions every time a change is made...

    Read the article

  • serving js libraries: better performance from google code or using asset packager?

    - by brahn
    I am working on a rails application that uses big javascript libraries (e.g. jquery UI), and I also have a handful of my own javascript files. I'm using asset packager to package up my own javascript. I'm considering two ways of serving these files: Link to the jQuery libraries from Google Code as described at http://code.google.com/apis/ajaxlibs/documentation/#jquery , and separately package up and serve my javascript files using asset packager. Host the jquery libraries myself, and package them together with my own javascript as one big merged javascript file. My hosting solution is of course not going to beat out Google's content delivery network, so at first I assumed that end users would experience faster page loads via option #1. However, it also occured to me that if I serve them myself, users would only need to issue one request to get the merged javascript (as opposed to one for my merged javascript and another for the libraries served by google). Which approach will provide the best end-user experience (presumably in the form of faster load times?)

    Read the article

  • Efficient heaps in purely functional languages

    - by Kim
    As an exercise in Haskell, I'm trying to implement heapsort. The heap is usually implemented as an array in imperative languages, but this would be hugely inefficient in purely functional languages. So I've looked at binary heaps, but everything I found so far describes them from an imperative viewpoint and the algorithms presented are hard to translate to a functional setting. How to efficiently implement a heap in a purely functional language such as Haskell? Edit: By efficient I mean it should still be in O(n*log n), but it doesn't have to beat a C program. Also, I'd like to use purely functional programming. What else would be the point of doing it in Haskell?

    Read the article

  • Simple Python Challenge: Fastest Bitwise XOR on Data Buffers

    - by user213060
    Challenge: Perform a bitwise XOR on two equal sized buffers. The buffers will be required to be the python str type since this is traditionally the type for data buffers in python. Return the resultant value as a str. Do this as fast as possible. The inputs are two 1 megabyte (2**20 byte) strings. The challenge is to substantially beat my inefficient algorithm using python or existing third party python modules (relaxed rules: or create your own module.) Marginal increases are useless. from os import urandom from numpy import frombuffer,bitwise_xor,byte def slow_xor(aa,bb): a=frombuffer(aa,dtype=byte) b=frombuffer(bb,dtype=byte) c=bitwise_xor(a,b) r=c.tostring() return r aa=urandom(2**20) bb=urandom(2**20) def test_it(): for x in xrange(1000): slow_xor(aa,bb)

    Read the article

  • How do I include 2 tables in one LocalStorage item?

    - by Noor
    I've got a table that you can edit, and I've got a simple code saving that list when you're done with editing it. (the tables have the contenteditable on) The problem I've stumbled upon is that if I double click on enter, the table gets divided into two separate tables with the same ID. This causes the code I'm using to set the localStorage to only store one of the tables (I assume the first).. I've thought of different solutions and I wonder if someone could point out the pro's and con's (if the solutions even works that is). Make a loop that checks the page after tables and stores them into an array of localStorage-items.. I'd have to dynamically create a localStorage item for each table. Take the whole div that the tables are in, and store that in the localStorage, when a user revisits the page, the page checks after the items in storage and displays the whole divs. Any suggestions you have that can beat this :).. (but no cache, it has to be with the localStorage!) Thanks

    Read the article

  • How to sift idioms and set phrases apart from other common phrases using NLP techniques?

    - by hippietrail
    What techniques exist that can tell the difference betwen plain common phrases such as "to the", "and the" and set phrases and idioms which have their own lexical meanings such as "pick up", "fall in love", "red herring", "dead end"? Are there techniques which are successful even without a dictionary, statistical methods HMMs train on large corpora for instance? Or are there heuristics such as ignoring or weighting down "promiscuous" words which can co-occur with just about any word versus words which occur either alone or in a specific limited set of idiomatic phrases? If there are such heuristics, how do we take into account set phrases and verbal phrases which do incorporate promiscuous words such as "up" in "beat up", "eat up", "sit up", "think up"? UPDATE I've found an interesting paper online: Unsupervised Type and Token Identi?cation of Idiomatic Expressions

    Read the article

  • How to get visual studio 10 to open .mk files in the same instance?

    - by Russ Schultz
    I've recently been migrated to windows 7, and upon re-installing VS2010, it seems to want to treat .mk files differently than it used to. For whatever reason, it insists on opening a new instance of visual studio to edit these files. It doesn't for .c, .h, etc. I've tried using types, a freeware association manager, to change how it is associated. I've deleted the association, recreated, etc. but it still seems to want to treat these separately. Anybody know how to beat this thing into submission?

    Read the article

  • Override transparency color when converting transparent PNG to JPG

    - by Alexander Malfait
    I'm using Dragonfly to generate thumbnail images in a Rails app. I'm serving all picture images as JPG's. Now the client is uploading transparent PNG files, like this one: http://www.ibanez.co.jp/products/images/eg2010/ART120_TRF_12_02.png Dragonfly uses RMagick to convert these images to JPG. The problem is that it converts the PNG images to JPG with a black background, and my site's design requires a white background. I've tried to override it like this: encoded_image = Magick::Image.from_blob(image.data).first if encoded_image.format.downcase == format image # do nothing else encoded_image.format = format encoded_image.background_color = "white" encoded_image.transparent_color = "white" encoded_image.to_blob end But the produced JPG images still contain a black background. Does anyone know how to beat RMagick into using a white background when converting the transparent layer? I know I could just serve as PNG, but then the images are 10 times as large, and the site is already pretty bandwidth heavy.

    Read the article

  • [ASP.NET] A CustomValidator doesn't need to have it's ControlToValidate property set, so...

    - by pkiyan
    Hi: I've just finished reading up on the CustomValidator control and I have a question. In the book I'm reading, it says that a CustomValidator doesn't need to have it's ControlToValidate property set and it gives a few examples of that usage. But in one example where ControlToValidate isn't used, the OnServerValidate function has a timer (5 seconds) that you need to beat by entering your 'answer' into a textbox. If it takes you longer than 5 seconds, the CustomValidator's error message pops up next to the textbox (it's like a timed question/answer game) . How did the CustomValidator know to place the message next to the textbox (there's no association between the two, that I know of)? I wanted to test this, so I put a couple more textboxes on the page and the error message always showed up next to the last textbox I placed on the page. Thanks.

    Read the article

  • Is it possible to parse a stylesheet with Nokogiri?

    - by wbharding
    I've spent my requisite two hours Googling this, and I can not find any good answers, so let's see if humans can beat Google computers. I want to parse a stylesheet in Ruby so that I can apply those styles to elements in my document (to make the styles inlined). So, I want to take something like <style> .mystyle { color:white; } </style> And be able to extract it into a Nokogiri object of some sort. The Nokogiri class "CSS::Parser" (http://nokogiri.rubyforge.org/nokogiri/Nokogiri/CSS/Parser.html) certainly has a promising name, but I can't find any documentation on what it is or how it works, so I have no idea if it can do what I'm after here. My end goal is to be able to write code something like: a_web_page = Nokogiri::HTML(html_page_as_string) parsed_styles = Nokogiri::CSS.parse(html_page_as_string) parsed_styles.each do |style| existing_inlined_style = a_web_page.css(style.declaration) || '' a_web_page.css(style.declaration)['css'] = existing_inlined_style + style.definition end Which would extract styles from a stylesheet and add them all as inlined styles to my document.

    Read the article

  • Screen scraping an application window and interacting with the mouse and keyboard

    - by ccook
    The other day I found myself addicted to a flash game and frustrated by the thing at the same time. In a moment of frustration with the game I thought I would make a 'bot' to beat it for me. Well, I really wouldn't, but it made me realize: I don't know how to interact with another application in a way to do this. Which brings me to the question, how would one take screenshots of another running application and interact with it with the keyboard and mouse. Ideally the solution would be in a managed language like c#. When doing the background reading the net was drowning with articles on scrapping HTML. There were not many articles on actually screen scrapping an application. Diverse answers are appreciated as I’m really looking at surveying what’s out there.

    Read the article

< Previous Page | 46 47 48 49 50 51 52 53 54 55 56 57  | Next Page >