Search Results

Search found 29203 results on 1169 pages for 'state machine workflow'.

Page 151/1169 | < Previous Page | 147 148 149 150 151 152 153 154 155 156 157 158  | Next Page >

• Problem with setup VPN in Ubuntu Server 12.04

  - by Yozone W.

  I have a problem with setup VPN server on my Ubuntu VPS, here is my server environments: Ubuntu Server 12.04 x86_64 xl2tpd 1.3.1+dfsg-1 pppd 2.4.5-5ubuntu1 openswan 1:2.6.38-1~precise1 After install software and configuration: ipsec verify Checking your system to see if IPsec got installed and started correctly: Version check and ipsec on-path [OK] Linux Openswan U2.6.38/K3.2.0-24-virtual (netkey) Checking for IPsec support in kernel [OK] SAref kernel support [N/A] NETKEY: Testing XFRM related proc values [OK] [OK] [OK] Checking that pluto is running [OK] Pluto listening for IKE on udp 500 [OK] Pluto listening for NAT-T on udp 4500 [OK] Checking for 'ip' command [OK] Checking /bin/sh is not /bin/dash [WARNING] Checking for 'iptables' command [OK] Opportunistic Encryption Support [DISABLED] /var/log/auth.log message: Oct 16 06:50:54 vpn pluto[3963]: packet from [My IP Address]:2251: received Vendor ID payload [RFC 3947] method set to=115 Oct 16 06:50:54 vpn pluto[3963]: packet from [My IP Address]:2251: received Vendor ID payload [draft-ietf-ipsec-nat-t-ike] meth=114, but already using method 115 Oct 16 06:50:54 vpn pluto[3963]: packet from [My IP Address]:2251: received Vendor ID payload [draft-ietf-ipsec-nat-t-ike-08] meth=113, but already using method 115 Oct 16 06:50:54 vpn pluto[3963]: packet from [My IP Address]:2251: received Vendor ID payload [draft-ietf-ipsec-nat-t-ike-07] meth=112, but already using method 115 Oct 16 06:50:54 vpn pluto[3963]: packet from [My IP Address]:2251: received Vendor ID payload [draft-ietf-ipsec-nat-t-ike-06] meth=111, but already using method 115 Oct 16 06:50:54 vpn pluto[3963]: packet from [My IP Address]:2251: received Vendor ID payload [draft-ietf-ipsec-nat-t-ike-05] meth=110, but already using method 115 Oct 16 06:50:54 vpn pluto[3963]: packet from [My IP Address]:2251: received Vendor ID payload [draft-ietf-ipsec-nat-t-ike-04] meth=109, but already using method 115 Oct 16 06:50:54 vpn pluto[3963]: packet from [My IP Address]:2251: received Vendor ID payload [draft-ietf-ipsec-nat-t-ike-03] meth=108, but already using method 115 Oct 16 06:50:54 vpn pluto[3963]: packet from [My IP Address]:2251: received Vendor ID payload [draft-ietf-ipsec-nat-t-ike-02] meth=107, but already using method 115 Oct 16 06:50:54 vpn pluto[3963]: packet from [My IP Address]:2251: received Vendor ID payload [draft-ietf-ipsec-nat-t-ike-02_n] meth=106, but already using method 115 Oct 16 06:50:54 vpn pluto[3963]: packet from [My IP Address]:2251: ignoring Vendor ID payload [FRAGMENTATION 80000000] Oct 16 06:50:54 vpn pluto[3963]: packet from [My IP Address]:2251: received Vendor ID payload [Dead Peer Detection] Oct 16 06:50:54 vpn pluto[3963]: "L2TP-PSK-NAT"[5] [My IP Address] #5: responding to Main Mode from unknown peer [My IP Address] Oct 16 06:50:54 vpn pluto[3963]: "L2TP-PSK-NAT"[5] [My IP Address] #5: transition from state STATE_MAIN_R0 to state STATE_MAIN_R1 Oct 16 06:50:54 vpn pluto[3963]: "L2TP-PSK-NAT"[5] [My IP Address] #5: STATE_MAIN_R1: sent MR1, expecting MI2 Oct 16 06:50:55 vpn pluto[3963]: "L2TP-PSK-NAT"[5] [My IP Address] #5: NAT-Traversal: Result using draft-ietf-ipsec-nat-t-ike (MacOS X): peer is NATed Oct 16 06:50:55 vpn pluto[3963]: "L2TP-PSK-NAT"[5] [My IP Address] #5: transition from state STATE_MAIN_R1 to state STATE_MAIN_R2 Oct 16 06:50:55 vpn pluto[3963]: "L2TP-PSK-NAT"[5] [My IP Address] #5: STATE_MAIN_R2: sent MR2, expecting MI3 Oct 16 06:50:55 vpn pluto[3963]: "L2TP-PSK-NAT"[5] [My IP Address] #5: ignoring informational payload, type IPSEC_INITIAL_CONTACT msgid=00000000 Oct 16 06:50:55 vpn pluto[3963]: "L2TP-PSK-NAT"[5] [My IP Address] #5: Main mode peer ID is ID_IPV4_ADDR: '192.168.12.52' Oct 16 06:50:55 vpn pluto[3963]: "L2TP-PSK-NAT"[5] [My IP Address] #5: switched from "L2TP-PSK-NAT" to "L2TP-PSK-NAT" Oct 16 06:50:55 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address] #5: deleting connection "L2TP-PSK-NAT" instance with peer [My IP Address] {isakmp=#0/ipsec=#0} Oct 16 06:50:55 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address] #5: transition from state STATE_MAIN_R2 to state STATE_MAIN_R3 Oct 16 06:50:55 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address] #5: new NAT mapping for #5, was [My IP Address]:2251, now [My IP Address]:2847 Oct 16 06:50:55 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address] #5: STATE_MAIN_R3: sent MR3, ISAKMP SA established {auth=OAKLEY_PRESHARED_KEY cipher=aes_256 prf=oakley_sha group=modp1024} Oct 16 06:50:55 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address] #5: Dead Peer Detection (RFC 3706): enabled Oct 16 06:50:56 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address] #5: the peer proposed: [My Server IP Address]/32:17/1701 -> 192.168.12.52/32:17/0 Oct 16 06:50:56 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address] #5: NAT-Traversal: received 2 NAT-OA. using first, ignoring others Oct 16 06:50:56 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address] #6: responding to Quick Mode proposal {msgid:8579b1fb} Oct 16 06:50:56 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address] #6: us: [My Server IP Address]<[My Server IP Address]>:17/1701 Oct 16 06:50:56 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address] #6: them: [My IP Address][192.168.12.52]:17/65280===192.168.12.52/32 Oct 16 06:50:56 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address] #6: transition from state STATE_QUICK_R0 to state STATE_QUICK_R1 Oct 16 06:50:56 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address] #6: STATE_QUICK_R1: sent QR1, inbound IPsec SA installed, expecting QI2 Oct 16 06:50:56 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address] #6: Dead Peer Detection (RFC 3706): enabled Oct 16 06:50:56 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address] #6: transition from state STATE_QUICK_R1 to state STATE_QUICK_R2 Oct 16 06:50:56 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address] #6: STATE_QUICK_R2: IPsec SA established transport mode {ESP=>0x08bda158 <0x4920a374 xfrm=AES_256-HMAC_SHA1 NATOA=192.168.12.52 NATD=[My IP Address]:2847 DPD=enabled} Oct 16 06:51:16 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address] #5: received Delete SA(0x08bda158) payload: deleting IPSEC State #6 Oct 16 06:51:16 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address] #5: ERROR: netlink XFRM_MSG_DELPOLICY response for flow eroute_connection delete included errno 2: No such file or directory Oct 16 06:51:16 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address] #5: received and ignored informational message Oct 16 06:51:16 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address] #5: received Delete SA payload: deleting ISAKMP State #5 Oct 16 06:51:16 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address]: deleting connection "L2TP-PSK-NAT" instance with peer [My IP Address] {isakmp=#0/ipsec=#0} Oct 16 06:51:16 vpn pluto[3963]: packet from [My IP Address]:2847: received and ignored informational message xl2tpd -D message: xl2tpd[4289]: Enabling IPsec SAref processing for L2TP transport mode SAs xl2tpd[4289]: IPsec SAref does not work with L2TP kernel mode yet, enabling forceuserspace=yes xl2tpd[4289]: setsockopt recvref[30]: Protocol not available xl2tpd[4289]: This binary does not support kernel L2TP. xl2tpd[4289]: xl2tpd version xl2tpd-1.3.1 started on vpn.netools.me PID:4289 xl2tpd[4289]: Written by Mark Spencer, Copyright (C) 1998, Adtran, Inc. xl2tpd[4289]: Forked by Scott Balmos and David Stipp, (C) 2001 xl2tpd[4289]: Inherited by Jeff McAdams, (C) 2002 xl2tpd[4289]: Forked again by Xelerance (www.xelerance.com) (C) 2006 xl2tpd[4289]: Listening on IP address [My Server IP Address], port 1701 Then it just stopped here, and have no any response. I can't connect VPN on my mac client, the /var/log/system.log message: Oct 16 15:17:36 azone-iMac.local configd[17]: SCNC: start, triggered by SystemUIServer, type L2TP, status 0 Oct 16 15:17:36 azone-iMac.local pppd[3799]: pppd 2.4.2 (Apple version 596.13) started by azone, uid 501 Oct 16 15:17:38 azone-iMac.local pppd[3799]: L2TP connecting to server 'vpn.netools.me' ([My Server IP Address])... Oct 16 15:17:38 azone-iMac.local pppd[3799]: IPSec connection started Oct 16 15:17:38 azone-iMac.local racoon[359]: Connecting. Oct 16 15:17:38 azone-iMac.local racoon[359]: IPSec Phase1 started (Initiated by me). Oct 16 15:17:38 azone-iMac.local racoon[359]: IKE Packet: transmit success. (Initiator, Main-Mode message 1). Oct 16 15:17:38 azone-iMac.local racoon[359]: IKE Packet: receive success. (Initiator, Main-Mode message 2). Oct 16 15:17:38 azone-iMac.local racoon[359]: IKE Packet: transmit success. (Initiator, Main-Mode message 3). Oct 16 15:17:38 azone-iMac.local racoon[359]: IKE Packet: receive success. (Initiator, Main-Mode message 4). Oct 16 15:17:38 azone-iMac.local racoon[359]: IKE Packet: transmit success. (Initiator, Main-Mode message 5). Oct 16 15:17:38 azone-iMac.local racoon[359]: IKEv1 Phase1 AUTH: success. (Initiator, Main-Mode Message 6). Oct 16 15:17:38 azone-iMac.local racoon[359]: IKE Packet: receive success. (Initiator, Main-Mode message 6). Oct 16 15:17:38 azone-iMac.local racoon[359]: IKEv1 Phase1 Initiator: success. (Initiator, Main-Mode). Oct 16 15:17:38 azone-iMac.local racoon[359]: IPSec Phase1 established (Initiated by me). Oct 16 15:17:39 azone-iMac.local racoon[359]: IPSec Phase2 started (Initiated by me). Oct 16 15:17:39 azone-iMac.local racoon[359]: IKE Packet: transmit success. (Initiator, Quick-Mode message 1). Oct 16 15:17:39 azone-iMac.local racoon[359]: IKE Packet: receive success. (Initiator, Quick-Mode message 2). Oct 16 15:17:39 azone-iMac.local racoon[359]: IKE Packet: transmit success. (Initiator, Quick-Mode message 3). Oct 16 15:17:39 azone-iMac.local racoon[359]: IKEv1 Phase2 Initiator: success. (Initiator, Quick-Mode). Oct 16 15:17:39 azone-iMac.local racoon[359]: IPSec Phase2 established (Initiated by me). Oct 16 15:17:39 azone-iMac.local pppd[3799]: IPSec connection established Oct 16 15:17:59 azone-iMac.local pppd[3799]: L2TP cannot connect to the server Oct 16 15:17:59 azone-iMac.local racoon[359]: IPSec disconnecting from server [My Server IP Address] Oct 16 15:17:59 azone-iMac.local racoon[359]: IKE Packet: transmit success. (Information message). Oct 16 15:17:59 azone-iMac.local racoon[359]: IKEv1 Information-Notice: transmit success. (Delete IPSEC-SA). Oct 16 15:17:59 azone-iMac.local racoon[359]: IKE Packet: transmit success. (Information message). Oct 16 15:17:59 azone-iMac.local racoon[359]: IKEv1 Information-Notice: transmit success. (Delete ISAKMP-SA). Anyone help? Thanks a million!

  Read the article

• Parallelism in .NET – Part 4, Imperative Data Parallelism: Aggregation

  - by Reed

  In the article on simple data parallelism, I described how to perform an operation on an entire collection of elements in parallel.  Often, this is not adequate, as the parallel operation is going to be performing some form of aggregation. Simple examples of this might include taking the sum of the results of processing a function on each element in the collection, or finding the minimum of the collection given some criteria.  This can be done using the techniques described in simple data parallelism, however, special care needs to be taken into account to synchronize the shared data appropriately.  The Task Parallel Library has tools to assist in this synchronization. The main issue with aggregation when parallelizing a routine is that you need to handle synchronization of data.  Since multiple threads will need to write to a shared portion of data.  Suppose, for example, that we wanted to parallelize a simple loop that looked for the minimum value within a dataset: double min = double.MaxValue; foreach(var item in collection) { double value = item.PerformComputation(); min = System.Math.Min(min, value); } .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; } This seems like a good candidate for parallelization, but there is a problem here.  If we just wrap this into a call to Parallel.ForEach, we’ll introduce a critical race condition, and get the wrong answer.  Let’s look at what happens here: // Buggy code! Do not use! double min = double.MaxValue; Parallel.ForEach(collection, item => { double value = item.PerformComputation(); min = System.Math.Min(min, value); }); This code has a fatal flaw: min will be checked, then set, by multiple threads simultaneously.  Two threads may perform the check at the same time, and set the wrong value for min.  Say we get a value of 1 in thread 1, and a value of 2 in thread 2, and these two elements are the first two to run.  If both hit the min check line at the same time, both will determine that min should change, to 1 and 2 respectively.  If element 1 happens to set the variable first, then element 2 sets the min variable, we’ll detect a min value of 2 instead of 1.  This can lead to wrong answers. Unfortunately, fixing this, with the Parallel.ForEach call we’re using, would require adding locking.  We would need to rewrite this like: // Safe, but slow double min = double.MaxValue; // Make a "lock" object object syncObject = new object(); Parallel.ForEach(collection, item => { double value = item.PerformComputation(); lock(syncObject) min = System.Math.Min(min, value); }); This will potentially add a huge amount of overhead to our calculation.  Since we can potentially block while waiting on the lock for every single iteration, we will most likely slow this down to where it is actually quite a bit slower than our serial implementation.  The problem is the lock statement – any time you use lock(object), you’re almost assuring reduced performance in a parallel situation.  This leads to two observations I’ll make: When parallelizing a routine, try to avoid locks. That being said: Always add any and all required synchronization to avoid race conditions. These two observations tend to be opposing forces – we often need to synchronize our algorithms, but we also want to avoid the synchronization when possible.  Looking at our routine, there is no way to directly avoid this lock, since each element is potentially being run on a separate thread, and this lock is necessary in order for our routine to function correctly every time. However, this isn’t the only way to design this routine to implement this algorithm.  Realize that, although our collection may have thousands or even millions of elements, we have a limited number of Processing Elements (PE).  Processing Element is the standard term for a hardware element which can process and execute instructions.  This typically is a core in your processor, but many modern systems have multiple hardware execution threads per core.  The Task Parallel Library will not execute the work for each item in the collection as a separate work item. Instead, when Parallel.ForEach executes, it will partition the collection into larger “chunks” which get processed on different threads via the ThreadPool.  This helps reduce the threading overhead, and help the overall speed.  In general, the Parallel class will only use one thread per PE in the system. Given the fact that there are typically fewer threads than work items, we can rethink our algorithm design.  We can parallelize our algorithm more effectively by approaching it differently.  Because the basic aggregation we are doing here (Min) is communitive, we do not need to perform this in a given order.  We knew this to be true already – otherwise, we wouldn’t have been able to parallelize this routine in the first place.  With this in mind, we can treat each thread’s work independently, allowing each thread to serially process many elements with no locking, then, after all the threads are complete, “merge” together the results. This can be accomplished via a different set of overloads in the Parallel class: Parallel.ForEach<TSource,TLocal>.  The idea behind these overloads is to allow each thread to begin by initializing some local state (TLocal).  The thread will then process an entire set of items in the source collection, providing that state to the delegate which processes an individual item.  Finally, at the end, a separate delegate is run which allows you to handle merging that local state into your final results. To rewriting our routine using Parallel.ForEach<TSource,TLocal>, we need to provide three delegates instead of one.  The most basic version of this function is declared as: public static ParallelLoopResult ForEach<TSource, TLocal>( IEnumerable<TSource> source, Func<TLocal> localInit, Func<TSource, ParallelLoopState, TLocal, TLocal> body, Action<TLocal> localFinally ) The first delegate (the localInit argument) is defined as Func<TLocal>.  This delegate initializes our local state.  It should return some object we can use to track the results of a single thread’s operations. The second delegate (the body argument) is where our main processing occurs, although now, instead of being an Action<T>, we actually provide a Func<TSource, ParallelLoopState, TLocal, TLocal> delegate.  This delegate will receive three arguments: our original element from the collection (TSource), a ParallelLoopState which we can use for early termination, and the instance of our local state we created (TLocal).  It should do whatever processing you wish to occur per element, then return the value of the local state after processing is completed. The third delegate (the localFinally argument) is defined as Action<TLocal>.  This delegate is passed our local state after it’s been processed by all of the elements this thread will handle.  This is where you can merge your final results together.  This may require synchronization, but now, instead of synchronizing once per element (potentially millions of times), you’ll only have to synchronize once per thread, which is an ideal situation. Now that I’ve explained how this works, lets look at the code: // Safe, and fast! double min = double.MaxValue; // Make a "lock" object object syncObject = new object(); Parallel.ForEach( collection, // First, we provide a local state initialization delegate. () => double.MaxValue, // Next, we supply the body, which takes the original item, loop state, // and local state, and returns a new local state (item, loopState, localState) => { double value = item.PerformComputation(); return System.Math.Min(localState, value); }, // Finally, we provide an Action<TLocal>, to "merge" results together localState => { // This requires locking, but it's only once per used thread lock(syncObj) min = System.Math.Min(min, localState); } ); Although this is a bit more complicated than the previous version, it is now both thread-safe, and has minimal locking.  This same approach can be used by Parallel.For, although now, it’s Parallel.For<TLocal>.  When working with Parallel.For<TLocal>, you use the same triplet of delegates, with the same purpose and results. Also, many times, you can completely avoid locking by using a method of the Interlocked class to perform the final aggregation in an atomic operation.  The MSDN example demonstrating this same technique using Parallel.For uses the Interlocked class instead of a lock, since they are doing a sum operation on a long variable, which is possible via Interlocked.Add. By taking advantage of local state, we can use the Parallel class methods to parallelize algorithms such as aggregation, which, at first, may seem like poor candidates for parallelization.  Doing so requires careful consideration, and often requires a slight redesign of the algorithm, but the performance gains can be significant if handled in a way to avoid excessive synchronization.

  Read the article

• Problem with setup VPN on Ubuntu Server 12.04

  - by Yozone W.

  I have a problem with setup VPN server on my Ubuntu VPS, here is my server environments: Ubuntu Server 12.04 x86_64 xl2tpd 1.3.1+dfsg-1 pppd 2.4.5-5ubuntu1 openswan 1:2.6.38-1~precise1 After install software and configuration: ipsec verify Checking your system to see if IPsec got installed and started correctly: Version check and ipsec on-path [OK] Linux Openswan U2.6.38/K3.2.0-24-virtual (netkey) Checking for IPsec support in kernel [OK] SAref kernel support [N/A] NETKEY: Testing XFRM related proc values [OK] [OK] [OK] Checking that pluto is running [OK] Pluto listening for IKE on udp 500 [OK] Pluto listening for NAT-T on udp 4500 [OK] Checking for 'ip' command [OK] Checking /bin/sh is not /bin/dash [WARNING] Checking for 'iptables' command [OK] Opportunistic Encryption Support [DISABLED] /var/log/auth.log message: Oct 16 06:50:54 vpn pluto[3963]: packet from [My IP Address]:2251: received Vendor ID payload [RFC 3947] method set to=115 Oct 16 06:50:54 vpn pluto[3963]: packet from [My IP Address]:2251: received Vendor ID payload [draft-ietf-ipsec-nat-t-ike] meth=114, but already using method 115 Oct 16 06:50:54 vpn pluto[3963]: packet from [My IP Address]:2251: received Vendor ID payload [draft-ietf-ipsec-nat-t-ike-08] meth=113, but already using method 115 Oct 16 06:50:54 vpn pluto[3963]: packet from [My IP Address]:2251: received Vendor ID payload [draft-ietf-ipsec-nat-t-ike-07] meth=112, but already using method 115 Oct 16 06:50:54 vpn pluto[3963]: packet from [My IP Address]:2251: received Vendor ID payload [draft-ietf-ipsec-nat-t-ike-06] meth=111, but already using method 115 Oct 16 06:50:54 vpn pluto[3963]: packet from [My IP Address]:2251: received Vendor ID payload [draft-ietf-ipsec-nat-t-ike-05] meth=110, but already using method 115 Oct 16 06:50:54 vpn pluto[3963]: packet from [My IP Address]:2251: received Vendor ID payload [draft-ietf-ipsec-nat-t-ike-04] meth=109, but already using method 115 Oct 16 06:50:54 vpn pluto[3963]: packet from [My IP Address]:2251: received Vendor ID payload [draft-ietf-ipsec-nat-t-ike-03] meth=108, but already using method 115 Oct 16 06:50:54 vpn pluto[3963]: packet from [My IP Address]:2251: received Vendor ID payload [draft-ietf-ipsec-nat-t-ike-02] meth=107, but already using method 115 Oct 16 06:50:54 vpn pluto[3963]: packet from [My IP Address]:2251: received Vendor ID payload [draft-ietf-ipsec-nat-t-ike-02_n] meth=106, but already using method 115 Oct 16 06:50:54 vpn pluto[3963]: packet from [My IP Address]:2251: ignoring Vendor ID payload [FRAGMENTATION 80000000] Oct 16 06:50:54 vpn pluto[3963]: packet from [My IP Address]:2251: received Vendor ID payload [Dead Peer Detection] Oct 16 06:50:54 vpn pluto[3963]: "L2TP-PSK-NAT"[5] [My IP Address] #5: responding to Main Mode from unknown peer [My IP Address] Oct 16 06:50:54 vpn pluto[3963]: "L2TP-PSK-NAT"[5] [My IP Address] #5: transition from state STATE_MAIN_R0 to state STATE_MAIN_R1 Oct 16 06:50:54 vpn pluto[3963]: "L2TP-PSK-NAT"[5] [My IP Address] #5: STATE_MAIN_R1: sent MR1, expecting MI2 Oct 16 06:50:55 vpn pluto[3963]: "L2TP-PSK-NAT"[5] [My IP Address] #5: NAT-Traversal: Result using draft-ietf-ipsec-nat-t-ike (MacOS X): peer is NATed Oct 16 06:50:55 vpn pluto[3963]: "L2TP-PSK-NAT"[5] [My IP Address] #5: transition from state STATE_MAIN_R1 to state STATE_MAIN_R2 Oct 16 06:50:55 vpn pluto[3963]: "L2TP-PSK-NAT"[5] [My IP Address] #5: STATE_MAIN_R2: sent MR2, expecting MI3 Oct 16 06:50:55 vpn pluto[3963]: "L2TP-PSK-NAT"[5] [My IP Address] #5: ignoring informational payload, type IPSEC_INITIAL_CONTACT msgid=00000000 Oct 16 06:50:55 vpn pluto[3963]: "L2TP-PSK-NAT"[5] [My IP Address] #5: Main mode peer ID is ID_IPV4_ADDR: '192.168.12.52' Oct 16 06:50:55 vpn pluto[3963]: "L2TP-PSK-NAT"[5] [My IP Address] #5: switched from "L2TP-PSK-NAT" to "L2TP-PSK-NAT" Oct 16 06:50:55 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address] #5: deleting connection "L2TP-PSK-NAT" instance with peer [My IP Address] {isakmp=#0/ipsec=#0} Oct 16 06:50:55 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address] #5: transition from state STATE_MAIN_R2 to state STATE_MAIN_R3 Oct 16 06:50:55 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address] #5: new NAT mapping for #5, was [My IP Address]:2251, now [My IP Address]:2847 Oct 16 06:50:55 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address] #5: STATE_MAIN_R3: sent MR3, ISAKMP SA established {auth=OAKLEY_PRESHARED_KEY cipher=aes_256 prf=oakley_sha group=modp1024} Oct 16 06:50:55 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address] #5: Dead Peer Detection (RFC 3706): enabled Oct 16 06:50:56 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address] #5: the peer proposed: [My Server IP Address]/32:17/1701 -> 192.168.12.52/32:17/0 Oct 16 06:50:56 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address] #5: NAT-Traversal: received 2 NAT-OA. using first, ignoring others Oct 16 06:50:56 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address] #6: responding to Quick Mode proposal {msgid:8579b1fb} Oct 16 06:50:56 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address] #6: us: [My Server IP Address]<[My Server IP Address]>:17/1701 Oct 16 06:50:56 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address] #6: them: [My IP Address][192.168.12.52]:17/65280===192.168.12.52/32 Oct 16 06:50:56 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address] #6: transition from state STATE_QUICK_R0 to state STATE_QUICK_R1 Oct 16 06:50:56 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address] #6: STATE_QUICK_R1: sent QR1, inbound IPsec SA installed, expecting QI2 Oct 16 06:50:56 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address] #6: Dead Peer Detection (RFC 3706): enabled Oct 16 06:50:56 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address] #6: transition from state STATE_QUICK_R1 to state STATE_QUICK_R2 Oct 16 06:50:56 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address] #6: STATE_QUICK_R2: IPsec SA established transport mode {ESP=>0x08bda158 <0x4920a374 xfrm=AES_256-HMAC_SHA1 NATOA=192.168.12.52 NATD=[My IP Address]:2847 DPD=enabled} Oct 16 06:51:16 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address] #5: received Delete SA(0x08bda158) payload: deleting IPSEC State #6 Oct 16 06:51:16 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address] #5: ERROR: netlink XFRM_MSG_DELPOLICY response for flow eroute_connection delete included errno 2: No such file or directory Oct 16 06:51:16 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address] #5: received and ignored informational message Oct 16 06:51:16 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address] #5: received Delete SA payload: deleting ISAKMP State #5 Oct 16 06:51:16 vpn pluto[3963]: "L2TP-PSK-NAT"[6] [My IP Address]: deleting connection "L2TP-PSK-NAT" instance with peer [My IP Address] {isakmp=#0/ipsec=#0} Oct 16 06:51:16 vpn pluto[3963]: packet from [My IP Address]:2847: received and ignored informational message xl2tpd -D message: xl2tpd[4289]: Enabling IPsec SAref processing for L2TP transport mode SAs xl2tpd[4289]: IPsec SAref does not work with L2TP kernel mode yet, enabling forceuserspace=yes xl2tpd[4289]: setsockopt recvref[30]: Protocol not available xl2tpd[4289]: This binary does not support kernel L2TP. xl2tpd[4289]: xl2tpd version xl2tpd-1.3.1 started on vpn.netools.me PID:4289 xl2tpd[4289]: Written by Mark Spencer, Copyright (C) 1998, Adtran, Inc. xl2tpd[4289]: Forked by Scott Balmos and David Stipp, (C) 2001 xl2tpd[4289]: Inherited by Jeff McAdams, (C) 2002 xl2tpd[4289]: Forked again by Xelerance (www.xelerance.com) (C) 2006 xl2tpd[4289]: Listening on IP address [My Server IP Address], port 1701 Then it just stopped here, and have no any response. I can't connect VPN on my mac client, the /var/log/system.log message: Oct 16 15:17:36 azone-iMac.local configd[17]: SCNC: start, triggered by SystemUIServer, type L2TP, status 0 Oct 16 15:17:36 azone-iMac.local pppd[3799]: pppd 2.4.2 (Apple version 596.13) started by azone, uid 501 Oct 16 15:17:38 azone-iMac.local pppd[3799]: L2TP connecting to server 'vpn.netools.me' ([My Server IP Address])... Oct 16 15:17:38 azone-iMac.local pppd[3799]: IPSec connection started Oct 16 15:17:38 azone-iMac.local racoon[359]: Connecting. Oct 16 15:17:38 azone-iMac.local racoon[359]: IPSec Phase1 started (Initiated by me). Oct 16 15:17:38 azone-iMac.local racoon[359]: IKE Packet: transmit success. (Initiator, Main-Mode message 1). Oct 16 15:17:38 azone-iMac.local racoon[359]: IKE Packet: receive success. (Initiator, Main-Mode message 2). Oct 16 15:17:38 azone-iMac.local racoon[359]: IKE Packet: transmit success. (Initiator, Main-Mode message 3). Oct 16 15:17:38 azone-iMac.local racoon[359]: IKE Packet: receive success. (Initiator, Main-Mode message 4). Oct 16 15:17:38 azone-iMac.local racoon[359]: IKE Packet: transmit success. (Initiator, Main-Mode message 5). Oct 16 15:17:38 azone-iMac.local racoon[359]: IKEv1 Phase1 AUTH: success. (Initiator, Main-Mode Message 6). Oct 16 15:17:38 azone-iMac.local racoon[359]: IKE Packet: receive success. (Initiator, Main-Mode message 6). Oct 16 15:17:38 azone-iMac.local racoon[359]: IKEv1 Phase1 Initiator: success. (Initiator, Main-Mode). Oct 16 15:17:38 azone-iMac.local racoon[359]: IPSec Phase1 established (Initiated by me). Oct 16 15:17:39 azone-iMac.local racoon[359]: IPSec Phase2 started (Initiated by me). Oct 16 15:17:39 azone-iMac.local racoon[359]: IKE Packet: transmit success. (Initiator, Quick-Mode message 1). Oct 16 15:17:39 azone-iMac.local racoon[359]: IKE Packet: receive success. (Initiator, Quick-Mode message 2). Oct 16 15:17:39 azone-iMac.local racoon[359]: IKE Packet: transmit success. (Initiator, Quick-Mode message 3). Oct 16 15:17:39 azone-iMac.local racoon[359]: IKEv1 Phase2 Initiator: success. (Initiator, Quick-Mode). Oct 16 15:17:39 azone-iMac.local racoon[359]: IPSec Phase2 established (Initiated by me). Oct 16 15:17:39 azone-iMac.local pppd[3799]: IPSec connection established Oct 16 15:17:59 azone-iMac.local pppd[3799]: L2TP cannot connect to the server Oct 16 15:17:59 azone-iMac.local racoon[359]: IPSec disconnecting from server [My Server IP Address] Oct 16 15:17:59 azone-iMac.local racoon[359]: IKE Packet: transmit success. (Information message). Oct 16 15:17:59 azone-iMac.local racoon[359]: IKEv1 Information-Notice: transmit success. (Delete IPSEC-SA). Oct 16 15:17:59 azone-iMac.local racoon[359]: IKE Packet: transmit success. (Information message). Oct 16 15:17:59 azone-iMac.local racoon[359]: IKEv1 Information-Notice: transmit success. (Delete ISAKMP-SA). Anyone help? Thanks a million!

  Read the article

• Upgrading Windows 8 boot to VHD to Windows 8.1&ndash;Step by step guide

  - by Liam Westley

  Originally posted on: http://geekswithblogs.net/twickers/archive/2013/10/19/upgrading-windows-8-boot-to-vhd-to-windows-8.1ndashstep-by.aspxBoot to VHD – dual booting Windows 7 and Windows 8 became easy When Windows 8 arrived, quite a few people decided that they would still dual boot their machines, and instead of mucking about with resizing disk partitions to free up space for Windows 8 they decided to use the boot from VHD feature to create a huge hard disc image into which Windows 8 could be installed.  Scott Hanselman wrote this installation guide, while I myself used the installation guide from Ed Bott of ZD net fame. Boot to VHD is a great solution, it achieves a dual boot, can be backed up easily and had virtually no effect on the original Windows 7 partition. As a developer who has dual booted Windows operating systems for years, hacking boot.ini files, the boot to VHD was a much easier solution. Upgrade to Windows 8.1 – ah, you can’t do that on a virtual disk installation (boot to VHD) Last week the final version of Windows 8.1 arrived, and I went into the Windows Store to upgrade.  Luckily I’m on a fast download service, and use an SSD, because once the upgrade was downloaded and prepared Windows informed that This PC can’t run Windows 8.1, and provided the reason, You can’t install Windows on a virtual drive.  You can see an image of the message and discussion that sparked my search for a solution in this Microsoft Technet forum post. I was determined not to have to resize partitions yet again and fiddle with VHD to disk utilities and back again, and in the end I did succeed in upgrading to a Windows 8.1 boot to VHD partition.  It takes quite a bit of effort though … tldr; Simple steps of how you upgrade Boot into Windows 7 – make a copy of your Windows 8 VHD, to become Windows 8.1 Enable Hyper-V in your Windows 8 (the original boot to VHD partition) Create a new virtual machine, attaching the copy of your Windows 8 VHD Start the virtual machine, upgrade it via the Windows Store to Windows 8.1 Shutdown the virtual machine Boot into Windows 7 – use the bcedit tool to create a new Windows 8.1 boot to VHD option (pointing at the copy) Boot into the new Windows 8.1 option Reactivate Windows 8.1 (it will have become deactivated by running under Hyper-V) Remove the original Windows 8 VHD, and in Windows 7 use bcedit to remove it from the boot menu Things you’ll need A system that can run Hyper-V under Windows 8 (Intel i5, i7 class CPU) Enough space to have your original Windows 8 boot to VHD and a copy at the same time An ISO or DVD for Windows 8 to create a bootable Windows 8 partition Step by step guide Boot to your base o/s, the real one, Windows 7. Make a copy of the Windows 8 VHD file that you use to boot Windows 8 (via boot from VHD) – I copied it from a folder on C: called VHD-Win8 to VHD-Win8.1 on my N: drive. Reboot your system into Windows 8, and enable Hyper-V if not already present (this may require reboot) Use the Hyper-V manager , create a new Hyper-V machine, using half your system memory, and use the option to attach an existing VHD on the main IDE controller – this will be the new copy you made in Step 2. Start the virtual machine, use Connect to view it, and you’ll probably discover it cannot boot as there is no boot record If this is the case, go to Hyper-V manager, edit the Settings for the virtual machine to attach an ISO of a Windows 8 DVD to the second IDE controller. Start the virtual machine, use Connect to view it, and it should now attempt a fresh installation of Windows 8.  You should select Advanced Options and choose Repair - this will make VHD bootable When the setup reboots your virtual machine, turn off the virtual machine, and remove the ISO of the Windows 8 DVD from the virtual machine settings. Start virtual machine, use Connect to view it.  You will see the devices to be re-discovered (including your quad CPU becoming single CPU).  Eventually you should see the Windows Login screen. You may notice that your desktop background (Win+D) will have turned black as your Windows installation has become deactivate due to the hardware changes between your real PC and Hyper-V. Fortunately becoming deactivated, does not stop you using the Windows Store, where you can select the update to Windows 8.1. You can now watch the progress joy of the Windows 8 update; downloading, preparing to update, checking compatibility, gathering info, preparing to restart, and finally, confirm restart - remember that you are restarting your virtual machine sitting on the copy of the VHD, not the Windows 8 boot to VHD you are currently using to run Hyper-V (confused yet?) After the reboot you get the real upgrade messages; setting up x%, xx%, (quite slow) After a while, Getting ready Applying PC Settings x%, xx% (really slow) Updating your system (fast) Setting up a few more things x%, (quite slow) Getting ready, again Accept license terms Express settings Confirmed previous password Next, I had to set up a Microsoft account – which is possibly now required, and not optional Using the Microsoft account required a 2 factor authorization, via text message, a 7 digit code for me Finalising settings Blank screen, HI .. We're setting up things for you (similar to original Windows 8 install) 'You can get new apps from the Store', below which is ’Installing your apps’ - I had Windows Media Center which is counts as an app from the Store ‘Taking care of a few things’, below which is ‘Installing your apps’ ‘Taking care of a few things’, below ‘Don't turn off your PC’ ‘Getting your apps ready’, below ‘Don't turn off your PC’ ‘Almost ready’, below ‘Don't turn off your PC’ … finally, we get the Windows 8.1 start menu, and a quick Win+D to check the desktop confirmed all the application icons I expected, pinned items on the taskbar, and one app moaning about a missing drive At this point the upgrade is complete – you can shutdown the virtual machine Reboot from the original Windows 8 and return to Windows 7 to configure booting to the Windows 8.1 copy of the VHD In an administrator command prompt do following use the bcdedit tool (from an MSDN blog about configuring VHD to boot in Windows 7) Type bcedit to list the current boot options, so you can copy the GUID (complete with brackets/braces) for the original Windows 8 boot to VHD Create a new menu option, copy of the Windows 8 option; bcdedit /copy {originalguid} /d "Windows 8.1" Point the new Windows 8.1 option to the copy of the VHD; bcdedit /set {newguid} device vhd=[D:]\Image.vhd Point the new Windows 8.1 option to the copy of the VHD; bcdedit /set {newguid} osdevice vhd=[D:]\Image.vhd Set autodetection of the HAL (may already be set); bcdedit /set {newguid} detecthal on Reboot from Windows 7 and select the new option 'Windows 8.1' on the boot menu, and you’ll have some messages to look at, as your hardware is redetected (as you are back from 1 CPU to 4 CPUs) ‘Getting devices ready, blank then %xx, with occasional blank screen, for the graphics driver, (fast-ish) Getting Ready message (fast) You will have to suffer one final reboots, choose 'Windows 8.1' and you can now login to a lovely Windows 8.1 start screen running on non virtualized hardware via boot to VHD After checking everything is running fine, you can now choose to Activate Windows, which for me was a toll free phone call to the automated system where you type in lots of numbers to be given a whole bunch of new activation codes. Once you’re happy with your new Windows 8.1 boot to VHD, and no longer need the Windows 8 boot to VHD, feel free to delete the old one.  I do believe once you upgrade, you are no longer licensed to use it anyway. There, that was simple wasn’t it? Looking at the huge list of steps it took to perform this upgrade, you may wonder whether I think this is worth it.  Well, I think it is worth booting to VHD.  It makes backups a snap (go to Windows 7, copy the VHD, you backed up the o/s) and helps with disk management – want to move the o/s, you can move the VHD and repoint the boot menu to the new location. The downside is that Microsoft has complete neglected to support boot to VHD as an upgradable option.  Quite a poor decision in my opinion, and if you read twitter and the forums quite a few people agree with that view.  It’s a shame this got missed in the work on creating the upgrade packages for Windows 8.1.

  Read the article

• How do I get this Cisco VPN client to connect?

  - by WebWeasel

  I've got Ubuntu 10.10 64 bit and installed network-manager-vpnc and configured the connection but I keep getting this: NetworkManager[1217]: <info> Starting VPN service 'org.freedesktop.NetworkManager.vpnc'... NetworkManager[1217]: <info> VPN service 'org.freedesktop.NetworkManager.vpnc' started (org.freedesktop.NetworkManager.vpnc), PID 4420 NetworkManager[1217]: <info> VPN service 'org.freedesktop.NetworkManager.vpnc' appeared, activating connections NetworkManager[1217]: <info> VPN plugin state changed: 1 NetworkManager[1217]: <info> VPN plugin state changed: 3 NetworkManager[1217]: <info> VPN connection 'CSI' (Connect) reply received. modem-manager: (net/tun0): could not get port's parent device NetworkManager[1217]: SCPlugin-Ifupdown: devices added (path: /sys/devices/virtual/net/tun0, iface: tun0) NetworkManager[1217]: SCPlugin-Ifupdown: device added (path: /sys/devices/virtual/net/tun0, iface: tun0): no ifupdown configuration found. kernel: [ 2281.723506] tun0: Disabled Privacy Extensions avahi-daemon[1109]: Withdrawing workstation service for tun0. NetworkManager[1217]: SCPlugin-Ifupdown: devices removed (path: /sys/devices/virtual/net/tun0, iface: tun0) NetworkManager[1217]: <warn> VPN plugin failed: 1 NetworkManager[1217]: <info> VPN plugin state changed: 6 NetworkManager[1217]: <info> VPN plugin state change reason: 0 NetworkManager[1217]: <warn> error disconnecting VPN: Could not process the request because no VPN connection was active. NetworkManager[1217]: <info> Policy set 'Auto eth0' (eth0) as default for IPv4 routing and DNS. NetworkManager[1217]: <info> Starting VPN service 'org.freedesktop.NetworkManager.vpnc'... NetworkManager[1217]: <info> VPN service 'org.freedesktop.NetworkManager.vpnc' started (org.freedesktop.NetworkManager.vpnc), PID 4547 NetworkManager[1217]: <info> VPN service 'org.freedesktop.NetworkManager.vpnc' appeared, activating connections NetworkManager[1217]: <info> VPN plugin state changed: 1 NetworkManager[1217]: <info> VPN plugin state changed: 3 I've seen a couple of bugs on Launchpad that could be the same thing or have I done something wrong?

  Read the article

• Action button: only true once per press

  - by Sidar

  I'm using SFML2.0 and am trying to make a wrapper class for my controller/joystick. I read all the input data from my controller and send it off to my controllable object. I want to have two types of buttons per button press, one that is continues(true false state ) and one that is an action and is set to false after the next frame update. Here is an example of how I set my button A to true or false with the SFML api. Whereas data is my struct of buttons, and A holds my true/false state every update. data.A = sf::Joystick::isButtonPressed(i,st::input::A); But I've also added "data.actionA" which represents the one time action state. Basically what I want is for actionA to be set false after the update its been set to true. I'm trying to keep track of the previous state. But I seem to fall into this loop where it toggles between true and false every update. Anyone an idea? Edit: Since I can't answer my own question yet here is my solution: data.actionA = data.A = sf::Joystick::isButtonPressed(i,st::input::A); if(prev.A) data.actionA = false; First I always set the actionA to the value of the button state. Then I check if the previous state of A is true. If so we negate the value.

  Read the article

• Design For Asynchronous User Interface

  - by Sohnee

  I have been working on a integration that has posed an interesting user interface conundrum that I would like suggestions for. The user interface is displayed within a third party product. The state of the interface is supplied by calls to a service I have written. There can be small delays between the actual state changing the the user interface changing due to the polling for state by the third party. When a user interacts with the user interface, requests are sent back to my application. This then affects the state and the next state poll request will update the user interface. The problem is that the delay between pressing a button and seeing the user interface update is perhaps 1 or 2 seconds and in usability testing I can see that people are clicking again before the user interface updates, thinking that they haven't properly clicked the first time. Given the constraints (we can only update the user interface via the polling mechanism - if we updated it when they clicked, the polling might return and overwrite the change causing unpredictable / undesirable results)... what can we do to make the user experience better. My current idea is to show a message for a couple of seconds so people know their click was accepted, the message would not be affected by the state polling, so wouldn't be prematurely removed / overwritten etc. I'm sure there are other ideas out there and I'm also confident someone has a better idea that I have!

  Read the article

• D key not working on Ubuntu

  - by Jonathan

  For some inexplicable reason the capital d key on my Ubuntu system is no longer producing output. Hitting caps lock and then d produces a D. I've tried multiple keyboards and the issue is the same. There's nothing bound to Shift+d under System Preferences Keyboard Shortcuts. xev produces the following: shift + a KeyPress event, serial 36, synthetic NO, window 0x4c00001, root 0x27a, subw 0x0, time 31268952, (130,-16), root:(1000,525), state 0x10, keycode 62 (keysym 0xffe2, Shift_R), same_screen YES, XLookupString gives 0 bytes: XmbLookupString gives 0 bytes: XFilterEvent returns: False KeyPress event, serial 36, synthetic NO, window 0x4c00001, root 0x27a, subw 0x0, time 31269376, (130,-16), root:(1000,525), state 0x11, keycode 38 (keysym 0x41, A), same_screen YES, XLookupString gives 1 bytes: (41) "A" XmbLookupString gives 1 bytes: (41) "A" XFilterEvent returns: False KeyRelease event, serial 36, synthetic NO, window 0x4c00001, root 0x27a, subw 0x0, time 31269584, (130,-16), root:(1000,525), state 0x11, keycode 38 (keysym 0x41, A), same_screen YES, XLookupString gives 1 bytes: (41) "A" XFilterEvent returns: False KeyRelease event, serial 36, synthetic NO, window 0x4c00001, root 0x27a, subw 0x0, time 31269608, (130,-16), root:(1000,525), state 0x11, keycode 62 (keysym 0xffe2, Shift_R), same_screen YES, XLookupString gives 0 bytes: XFilterEvent returns: False shift + d KeyPress event, serial 36, synthetic NO, window 0x4c00001, root 0x27a, subw 0x0, time 31102792, (115,-13), root:(985,528), state 0x10, keycode 62 (keysym 0xffe2, Shift_R), same_screen YES, XLookupString gives 0 bytes: XmbLookupString gives 0 bytes: XFilterEvent returns: False FocusOut event, serial 36, synthetic NO, window 0x4c00001, mode NotifyGrab, detail NotifyAncestor FocusIn event, serial 36, synthetic NO, window 0x4c00001, mode NotifyUngrab, detail NotifyAncestor KeymapNotify event, serial 36, synthetic NO, window 0x0, keys: 2 0 0 0 0 0 0 64 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 KeyRelease event, serial 36, synthetic NO, window 0x4c00001, root 0x27a, subw 0x0, time 31103104, (115,-13), root:(985,528), state 0x11, keycode 62 (keysym 0xffe2, Shift_R), same_screen YES, XLookupString gives 0 bytes: XFilterEvent returns: False

  Read the article

• What are functional-programming ways of implementing Conway's Game of Life

  - by George Mauer

  I recently implemented for fun Conway's Game of Life in Javascript (actually coffeescript but same thing). Since javascript can be used as a functional language I was trying to stay to that end of the spectrum. I was not happy with my results. I am a fairly good OO programmer and my solution smacked of same-old-same-old. So long question short: what is the (pseudocode) functional style of doing it? Here is Pseudocode for my attempt: class Node update: (board) -> get number_of_alive_neighbors from board get this_is_alive from board if this_is_alive and number_of_alive_neighbors < 2 then die if this_is_alive and number_of_alive_neighbors > 3 then die if not this_is_alive and number_of_alive_neighbors == 3 then alive class NodeLocations at: (x, y) -> return node value at x,y of: (node) -> return x,y of node class Board getNeighbors: (node) -> use node_locations to check 8 neighbors around node and return count nodes = for 1..100 new Node state = new NodeState(nodes) locations = new NodeLocations(nodes) board = new Board(locations, state) executeRound: state = clone state accumulated_changes = for n in nodes n.update(board) apply accumulated_changes to state board = new Board(locations, state)

  Read the article

• Custom Session Management using HashTable

  - by kaleidoscope

  ASP.NET session state lets you associate a server-side string or object dictionary containing state data with a particular HTTP client session. A session is defined as a series of requests issued by the same client within a certain period of time, and is managed by associating a session ID with each unique client. The ID is supplied by the client on each request, either in a cookie or as a special fragment of the request URL. The session data is stored on the server side in one of the supported session state stores, which include in-process memory, SQL Server™ database, and the ASP.NET State Server service. The latter two modes enable session state to be shared among multiple Web servers on a Web farm and do not require server affinity. Implement Custom session Handler you need to follow following process : 1. Create class library which will inherit from  SessionStateStoreProviderBase abstract Class. 2. Implement all abstract Method in your base class. 3.Change Mode of session to “Custom” in web.config file and provide Provider as your Namespace with classname. <sessionState mode=”Custom” customProvider=”Namespace.classname”> <Providers> <add name=”Name” type=”Namespace.classname”> </sessionstate> For more Details Please refer following links :   http://msdn.microsoft.com/en-us/magazine/cc163730.aspx http://msdn.microsoft.com/en-us/library/system.web.sessionstate.sessionstatestoreproviderbase.aspx - Chandraprakash, S Technorati Tags: Chandraprakash,Session state Managment

  Read the article

• How lookaheads are propagated in "channel" method of building LALR parser?

  - by greenoldman

  The method is described in Dragon Book, however I read about it in ""Parsing Techniques" by D.Grune and C.J.H.Jacobs". I start from my understanding of building channels for NFA: channels are built once, they are like water channels with current you "drop" lookahead symbols in right places (sources) of the channel, and they propagate with "current" when symbol propagates, there are no barriers (the only sufficient things for propagation are presence of channel and direction/current); i.e. lookahead cannot just die out of the blue Is that right? If I am correct, then eof lookahead should be present in all states, because the source of it is the start production, and all other production states are reachable from start state. How the DFA is made out of this NFA is not perfectly clear for me -- the authors of the mentioned book write about preserving channels, but I see no purpose, if you propagated lookaheads. If the channels have to be preserved, are they cut off from the source if the DFA state does not include source NFA state? I assume no -- the channels still runs between DFA states, not only within given DFA state. In the effect eof should still be present in all items in all states. But when you take a look at DFA presented in book (pdf is from errata): DFA for LALR (fig. 9.34 in the book, p.301) you will see there are items without eof in lookahead. The grammar for this DFA is: S -> E E -> E - T E -> T T -> ( E ) T -> n So how it was computed, when eof was dropped, and on what condition? Update It is textual pdf, so two interesting states (in DFA; # is eof): State 1: S--- >•E[#] E--- >•E-T[#-] E--- >•T[#-] T--- >•n[#-] T--- >•(E)[#-] State 6: T--- >(•E)[#-)] E--- >•E-T[-)] E--- >•T[-)] T--- >•n[-)] T--- >•(E)[-)] Arc from 1 to 6 is labeled (.

  Read the article

• which style of member-access is preferable

  - by itwasntpete

  the purpose of oop using classes is to encapsulate members from the outer space. i always read that accessing members should be done by methods. for example: template<typename T> class foo_1 { T state_; public: // following below }; the most common doing that by my professor was to have a get and set method. // variant 1 T const& getState() { return state_; } void setState(T const& v) { state_ = v; } or like this: // variant 2 // in my opinion it is easier to read T const& state() { return state_; } void state(T const& v) { state_ = v; } assume the state_ is a variable, which is checked periodically and there is no need to ensure the value (state) is consistent. Is there any disadvantage of accessing the state by reference? for example: // variant 3 // do it by reference T& state() { return state_; } or even directly, if I declare the variable as public. template<typename T> class foo { public: // variant 4 T state; }; In variant 4 I could even ensure consistence by using c++11 atomic. So my question is, which one should I prefer?, Is there any coding standard which would decline one of these pattern? for some code see here

  Read the article

• Capital D key not working / producing output

  - by Jonathan

  For some inexplicable reason the capital d key on my Ubuntu system is no longer producing output. Hitting caps lock and then d produces a D. I've tried multiple keyboards and the issue is the same. There's nothing bound to Shift+d under System Preferences Keyboard Shortcuts. xev produces the following: shift + a KeyPress event, serial 36, synthetic NO, window 0x4c00001, root 0x27a, subw 0x0, time 31268952, (130,-16), root:(1000,525), state 0x10, keycode 62 (keysym 0xffe2, Shift_R), same_screen YES, XLookupString gives 0 bytes: XmbLookupString gives 0 bytes: XFilterEvent returns: False KeyPress event, serial 36, synthetic NO, window 0x4c00001, root 0x27a, subw 0x0, time 31269376, (130,-16), root:(1000,525), state 0x11, keycode 38 (keysym 0x41, A), same_screen YES, XLookupString gives 1 bytes: (41) "A" XmbLookupString gives 1 bytes: (41) "A" XFilterEvent returns: False KeyRelease event, serial 36, synthetic NO, window 0x4c00001, root 0x27a, subw 0x0, time 31269584, (130,-16), root:(1000,525), state 0x11, keycode 38 (keysym 0x41, A), same_screen YES, XLookupString gives 1 bytes: (41) "A" XFilterEvent returns: False KeyRelease event, serial 36, synthetic NO, window 0x4c00001, root 0x27a, subw 0x0, time 31269608, (130,-16), root:(1000,525), state 0x11, keycode 62 (keysym 0xffe2, Shift_R), same_screen YES, XLookupString gives 0 bytes: XFilterEvent returns: False shift + d KeyPress event, serial 36, synthetic NO, window 0x4c00001, root 0x27a, subw 0x0, time 31102792, (115,-13), root:(985,528), state 0x10, keycode 62 (keysym 0xffe2, Shift_R), same_screen YES, XLookupString gives 0 bytes: XmbLookupString gives 0 bytes: XFilterEvent returns: False FocusOut event, serial 36, synthetic NO, window 0x4c00001, mode NotifyGrab, detail NotifyAncestor FocusIn event, serial 36, synthetic NO, window 0x4c00001, mode NotifyUngrab, detail NotifyAncestor KeymapNotify event, serial 36, synthetic NO, window 0x0, keys: 2 0 0 0 0 0 0 64 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 KeyRelease event, serial 36, synthetic NO, window 0x4c00001, root 0x27a, subw 0x0, time 31103104, (115,-13), root:(985,528), state 0x11, keycode 62 (keysym 0xffe2, Shift_R), same_screen YES, XLookupString gives 0 bytes: XFilterEvent returns: False

  Read the article

• jQuery custom validation for a selected radio selection

  - by Kaushik Gopal

  Hey peeps, This is my requirement: I have a bunch of radio box selections (types of workflows). If one of the radios are selected(i.e one particular type of workflow selected), I want to run a custom validation on that. This is what i tried, but it's not behaving well. Any help? jQuery part: $(document).ready(function() { // this part is to expand the child radio selection if particular parent workflow selected $("#concernedDirectorChoice").hide(); $("input[name^=workflowChoice]").change( function (){ if($(this).attr("class")=='chooseDir'){ $("#concernedDirectorChoice").show(); }else{ $("#concernedDirectorChoice").hide(); } }); // FORM VALIDATION $.validator.addMethod("dirRequired", function(value, element) { return this.optional(element) || ($("input[name^=rdDir:checked]").length); }, "That particular workflow requires a Director to be chosen. Please select Director"); $("#contExpInitiateForm").validate({ debug:true ,rules:{ RenewalNo: {required: true, number: true}, chooseDir: {dirRequired: true}, workflowChoice: {required: true} } ,errorPlacement: function(error, element) { $('.errorMessageBox').text(error.html()); } }); }); HTML form part: <!-- Pick type of workflow --> <table class="hr-table" > <tr> <td class="hr-table-label " colspan=2 >Pick Workflow Type</td> </tr> <tr> <td> <input type="radio" name="workflowChoice" value="1"> </input> </td> <td> Workflow 1 </td> </tr> <tr> <td> <input type="radio" name="workflowChoice" value="2" class="chooseDir"> </input> </td> <td> Workflow 2 (Dir selection required) </td> </tr> <tr> <td> <input type="radio" name="workflowChoice" value="3"> </input> </td> <td> Workflow 3 </td> </tr> </table> <!-- Pick Director for Workflow type 2 --> <table id="concernedDirectorChoice" name="concernedDirectorChoice" > <tr><td class="hr-table-label" colspan=2 > Choose Concerned Director</td></tr> <tr> <td><input type="radio" value='Dir1' name="rdDir" /></td> <td>Director 1</td> </tr> <tr> <td><input type="radio" value='Dir2' name="rdDir" /></td> <td>Director 2</td> </tr> <tr> <td><input type="radio" value='Dir3' name="rdDir" /></td> <td>Director 3</td> </tr> </table>

  Read the article

• Are there some cases where Python threads can safely manipulate shared state?

  - by erikg

  Some discussion in another question has encouraged me to to better understand cases where locking is required in multithreaded Python programs. Per this article on threading in Python, I have several solid, testable examples of pitfalls that can occur when multiple threads access shared state. The example race condition provided on this page involves races between threads reading and manipulating a shared variable stored in a dictionary. I think the case for a race here is very obvious, and fortunately is eminently testable. However, I have been unable to evoke a race condition with atomic operations such as list appends or variable increments. This test exhaustively attempts to demonstrate such a race: from threading import Thread, Lock import operator def contains_all_ints(l, n): l.sort() for i in xrange(0, n): if l[i] != i: return False return True def test(ntests): results = [] threads = [] def lockless_append(i): results.append(i) for i in xrange(0, ntests): threads.append(Thread(target=lockless_append, args=(i,))) threads[i].start() for i in xrange(0, ntests): threads[i].join() if len(results) != ntests or not contains_all_ints(results, ntests): return False else: return True for i in range(0,100): if test(100000): print "OK", i else: print "appending to a list without locks *is* unsafe" exit() I have run the test above without failure (100x 100k multithreaded appends). Can anyone get it to fail? Is there another class of object which can be made to misbehave via atomic, incremental, modification by threads? Do these implicitly 'atomic' semantics apply to other operations in Python? Is this directly related to the GIL?

  Read the article

• Operation is not valid due to the current state of the object?

  - by Bill

  I am programming in C#; the code was working about a week ago, however it throws an exception and I don't understand at all what could be wrong with it. Var root = new CalculationNode(); -> Throw exception. In the call stack thats the only thing listed, I've been told that it could be that I need a clean build, but I am open to any ideas or suggestions. Thanks, -Bill Update: Exception's Detail System.InvalidOperationException was unhandled by user code Message=Operation is not valid due to the current state of the object. Source=Calculator.Logic StackTrace: at ~.Calculator.Logic.MyBaseExpressionParser.Parse(String expression) in ~\Source\Calculator.Logic\MyBaseExpressionParser.cs:line 44 at ~.Calculator.Logic.Tests.MyBaseCalculatorServiceTests.BasicMathDivision() in ~\Projects\Tests\Calculator.Logic.Tests\MyBaseCalculatorServiceTests.cs:line 60 InnerException: CalculationNode's code: public sealed calss CalculationNode { public CalculationNode() { this.Left = null; this.Right = null; this.Element = new CalculationElement(); } public CalculationNode Left {get;set;} public CalculationNode Right {get;set;} public CalculationElement Element {get; set;} } CalculationElement's code: public sealed class CalculationElement { public CalculationElement() { Value = string.Empty; IsOperator = false; } public string Value {get; set} public bool IsOperator {get; set} }

  Read the article

• Why does a change of Session State provider lead to an ASPx page yielding garbage?

  - by Rory Becker

  I have an aspnet webapp which has worked very well up until now. I was recently asked to explore ways of making it scale better. I found that seperation of database and Webapp would help. Further I was told that if I changed my session providing mechanism to SQLServer, I would be able to duplicate the Web Stack to several machines which could each call back to the state server allowing the load to be distirbuted better. This sounds logical. So I created an ASPState database using ASPNet_RegSQL.exe as detailed in many locations across the web and changed the web.config on my app from: <sessionState mode="InProc" cookieless="false" timeout="20" /> To: <sessionState mode="SQLServer" sqlConnectionString="Server=SomeSQLServer;user=SomeUser;password=SomePassword" cookieless="false" timeout="20" /> Then I addressed my app, which presented me with its logon screen and I duly logged in. Once in I was presented, not with the page I was expecting, but with: I can change the sessionstate back and forth. This problem goes away and then comes back based on which set of configuration I use. Why is this happening?

  Read the article

• Oracle EBS?????(Order->AR)

  - by Pan.Tian

  ???? ??:Order Management > Orders,Returns > Sales Orders ???????,??,????,???? ???????,????,??... ??Book Order,??Book??,????????Status??????“Booked”,???????"Awaiting Shipping",?????????,??????????????? ??:??Book??,????????????,????Shipping Transactions Form,????,?????????Line Status?Ready to Release,Next Step?Pick Release Pick Release ??:Order Management > Shipping > Release Sales Orders > Release Sales Orders Pick Release????(?????????).?Order  Number?????????? Auto Pick Confirm???No Auto Allocate???N Auto Allocate?Auto Pick Confirm??????Yes,???????????,??????No,???Yes??,?????Allocate?Pick Confirm??,??????????? ??????????Pick  Release,”Concurrent“??Pick Release?????Concurrent Request???,"Execute Now"????????Pick Release,??????????????User,??????Concurrent??? Pick Release?????????Pick Release?????Pick Wave??Move Order,??Move Order????????????????????(Staging),????INV??????????? INV_MOVE_ORDER_PUB.CREATE_MOVE_ORDER_HEADER???Move Order??(??Pick Release?????????????:Pick Release Process) ????????,?Pick Release??,?????????????Reservation(??),?????????Soft Reservations,?????????????,????Org?????????? ??:????,Shipping Transaction?Line Status?"Released to Warehouse",Next Step?"Transact Move Order";????????Booked,?????”Awaiting Shipping“? Pick Confirm Pick Confirm(????)????????Transact Move Order????,?Allocate????,?Transact Move Order. ??:Inventory > Move Orders > Transact Move Orders ????,Pick Wave??Tab,????? ??TMO????,??Allocate,Allocate?????????Picking Rule?????,??????Suggestion????,Suggestion?????? MTL_MATERIAL_TRANSACTIONS_TEMP?(?Pending Transactions)? ????Allocate??,??????Allocation????Single,Multiple??None???,Single??, ??????????Suggestion?Transaction??,Multiple???????;None??????Suggestion? ?(????????????????) ????????Transact??Move Order ?Transact??,Inventory Transaction Manager ???Suggestion Transactions(MMTT),???????????????,??????Subinventory??????(Staging)??? Transction???Material Transaction?Form????? ????Reservation??,?Transact??,???????,Reservation????????,????Sub,locator???? ??:????,Shipping Transaction?Line Status?"Staged/Pick Confirmed",Next Step?"Ship Confirm/Close Trip Stop";????????Booked,??????”Picked“? Ship Confirm Deliveries ??:Order Management > Shipping > Transactions ???Delivery??,??Ship Confirm(????),????Pick Release???,????Autocreate Delivery,???????Define Shipping Parameters????????,??shipping parameters???????,?????????Ship Confirm?????Action->Auto-create Deliveries. Delivery????????????????,????????.... Delivery??,??Ship Confirm???,???????,"Defer Interface"?????,?????????Interface Trip Stop SRS,????Defer Interface,?OK? Delivery was successfully confirmed!!! Ship Confirm????????????MTL_TRANSACTIONS_INTERFACE??,??MTI??????Sales Order Issue,??????????Interface Trip Stop???,???MTI??MMT??? ??:????,Shipping Transaction?Line Status?"Shipped",Next Step?"Run Interfaces";????????Booked,??????”Shipped“? Interface Trip Stop - SRS ?????Ship Confirm??????Defer Interface,??????????????Interface Trip Stop - SRS? ??:Order Management > Shipping > Interface > Run > Request:Interface Trip Stop - SRS Interface Trip Stop????????:Inventory Interface  SRS(????????)? Order Management Interface  SRS(?????????????AR??)? Inventory Interface  SRS???Shipping Transaction??????MTI,??INV Manager????MTI????MMT??,??Sales Order Issue?transaction??????,???????????Reservation????Inventory Interface  SRS?????,???WSH_DELIVERY_DETAILS??INV_INTERFACED_FLAG???Y? Order Management Interface - SRS??Inventory Interface  SRS?????,??Request?????????????AR??,OM Interface????????WSH_DELIVERY_DETAILS??OE_INTERFACED_FLAG?Y? ??:????,Shipping Transaction?Line Status?"Interfaced",Next Step?"Not Applicable";????????Booked,??????”Shipped“? Workflow background Process ??:Inventory > Workflow Background Engine Item Type:OM Order Line Process Deferred:Yes Process Timeout:No ??program????Deffered???workflow,Workflow Background Process???,???????Order????RA Interface???(RA_INTERFACE_LINES_ALL,RA_INTERFACE_SALESCREDITS_ALL,RA_Interface_distribution) ????????SQL???RA Interface??: 1.SELECT * FROM RA_INTERFACE_LINES_ALL WHERE sales_order = '65961'; 2.SELECT * FROM RA_INTERFACE_SALESCREDITS_ALL WHERE INTERFACE_LINE_ID IN (SELECT INTERFACE_LINE_ID FROM RA_INTERFACE_LINES_ALL WHERE sales_order = '65961' ); 3.SELECT * FROM RA_INTERFACE_DISTRIBUTIONS_ALL WHERE INTERFACE_LINE_ID IN (SELECT INTERFACE_LINE_ID FROM RA_INTERFACE_LINES_ALL WHERE sales_order = '65961' ); ?????RA Interface??,??OE_ORDER_LINES_ALL?INVOICE_INTERFACE_STATUS_CODE????? Yes,INVOICED_QUANTITY?????????????????????????Closed,????????Booked? AutoInvoice ????AR?? ??:Account Receivable > Interface > AutoInvoice Name:Autoinvoice Master Program Invoice Source:Order Entry Default Day:???? ???,?request????”Autoinvoice Import Program“???? ???,????Auto Invoice Program????RA?interface?,?????????????,???????AR???? (RA_CUSTOMER_TRX_ALL,RA_CUSTOMER_TRX_LINES,AR_PAYMENT_SCHEDULES). ?????? Order > Action > Additional Information > Invoices/Credit Memos????????,???????SQL?????AR??, SELECT ooha.order_number , oola.line_number so_line_number , oola.ordered_item , oola.ordered_quantity * oola.unit_selling_price so_extended_price , rcta.trx_number invoice_number , rcta.trx_date , rctla.line_number inv_line_number , rctla.unit_selling_price inv_unit_selling_price FROM oe_order_headers_all ooha , oe_order_lines_all oola , ra_customer_trx_all rcta , ra_customer_trx_lines_all rctla WHERE ooha.header_id = oola.header_id AND rcta.customer_trx_id = rctla.customer_trx_id AND rctla.interface_line_attribute6 = TO_CHAR (oola.line_id) AND rctla.interface_line_attribute1 = TO_CHAR (ooha.order_number) AND order_number = :p_order_number; ??Autoinvoice Import Program???error???,?????RA_INTERFACE_ERRORS_ALL?Message_text??,???????? Closing the Order ?????????,?????????(Close??Cancel)?0.5?,??????Workflow Background Process??????? ????????:you can wait until month-end and the “Order Flow – Generic” workflow will close it for you. Order&Shipping Transactions Status Summary Step Order Header Status Order Line Status Order Flow Workflow Status (Order Header) Line Flow Workflow Status (Order Line) Shipping Transaction  Status(RELEASED_STATUS in WDD) 1. Enter an Order Entered Entered Book Order Manual Enter – Line                              N/A 2. Book the Order Booked Awaiting Shipping Close Order Schedule ->Create Supply ->Ship – Line                       Ready to Release(R) 3. Pick the Order Booked Picked Close Order Ship – Line 1.Released to Warehouse(S)(Pick Release but not pick confirm) 2.Staged/Pick Confirmed(Y)(After pick confirm) 4. Ship the Order Booked Shipped Close Order Fulfill – Deferred 1.Shipped(After ship confirm) 2.Interfaced(C)(After ITS) Booked Closed Close Order Fulfill ->Invoice Interface ->Close Line -> End 5. Close the Order Closed Closed End End ????,shipping txn???,??????????:http://blog.csdn.net/pan_tian/article/details/7696528 ======EOF======

  Read the article

• Is it possible to "stealth" dual boot a machine?

  - by BrianH

  I have a loaner laptop that has MS Windows with locked down permissions. It works okay for what I need to do, but I started wondering if there was a way to install a separate Windows OS on a separate hard drive to do what I want to do on it. Virtual I wish I could use VirtualBox or VMWare, but that is not an option (I even tried VBox portable). External Drive My next trial was see if it was possible to install Windows on an external drive, and then plug that drive in and boot from it whenever I wanted my own OS. After a few Google searches, I see that is not really a possibility. Swap Primary Drive Another option, would be to get a second internal hard drive, take the existing HD out, and install a new Windows OS on the secondary HD. This would mean swapping the internal hard drive each time I want to switch OSs - doable, but not very convenient. Dual Boot The laptop has an expansion slot where a second hard drive can be plugged in quickly. I thought about Dual booting, but I don't want to mess with the MBR on the primary hard drive. When I have to give the laptop back, I don't want a dual-boot screen to popup. Summary Is there a way to have 2 hard-drives on a machine, each with it's own OS, and maybe use BIOS settings to have only 1 hard drive active at a time? That way both hard drives could be physically connected, but only one would actually be active at a time. I basically want a second OS that does not (can not) affect the existing OS in any way, and can be removed at any time without affecting the existing OS. The secondary OS does not need any of the files on the main hard drive - it's basically like having 2 separate computers using the same hard ware... Is this possible, or would it be easier just to go out and buy a different laptop? Thanks in advance! EDIT I just discovered that my BIOS allows me to pick (at startup) which hard drive I want to boot from. I poked around in the BIOS and there is not a place to disable certain devices, like the primary hard drive. My only concern about plugging in a second hard drive and installing Windows to the second hard drive is that it will mess with the primary hard drive, or add a bootloader screen to pick which windows install to use. My thought would be to physically unplug the primary, plug in the secondary and install windows to the secondary. After the install is working properly, I can plug the primary back in and use the BIOS feature to determine which drive to boot to. Is there any way after I have 2 separate installs on 2 separate hard drives that one of the installs could mess with the MBR on the other drive?

  Read the article

• Runge-Kutta (RK4) integration for game physics

  - by Kai

  Gaffer on Games has a great article about using RK4 integration for better game physics. The implementation is straightforward but the math behind it confuses me. I understand derivatives and integrals on a conceptual level but I haven't manipulated equations in a long time. Here's the brunt of Gaffer's implementation: void integrate(State &state, float t, float dt) { Derivative a = evaluate(state, t, 0.0f, Derivative()); Derivative b = evaluate(state, t+dt*0.5f, dt*0.5f, a); Derivative c = evaluate(state, t+dt*0.5f, dt*0.5f, b); Derivative d = evaluate(state, t+dt, dt, c); const float dxdt = 1.0f/6.0f * (a.dx + 2.0f*(b.dx + c.dx) + d.dx); const float dvdt = 1.0f/6.0f * (a.dv + 2.0f*(b.dv + c.dv) + d.dv) state.x = state.x + dxdt * dt; state.v = state.v + dvdt * dt; } Can anybody explain in simple terms how RK4 works? Specifically, why are we averaging the derivatives at 0.0f, 0.5f, 0.5f, and 1.0f? How is averaging derivatives up to the 4th order different from doing a simple euler integration with a smaller timestep? After reading the accepted answer below, and several other articles, I have a grasp on how RK4 works. To answer my own questions: Can anybody explain in simple terms how RK4 works? RK4 takes advantage of the fact that we can get a much better approximation of a function if we use its higher-order derivatives rather than just the first or second derivative. That's why the Taylor series converges much faster than Euler approximations. (take a look at the animation on the right side of that page) Specifically, why are we averaging the derivatives at 0.0f, 0.5f, 0.5f, and 1.0f? The Runge-Kutta method is an approximation of a function that samples derivatives of several points within a timestep, unlike the Taylor series which only samples derivatives of a single point. After sampling these derivatives we need to know how to weigh each sample to get the closest approximation possible. An easy way to do this is to pick constants that coincide with the Taylor series, which is how the constants of a Runge-Kutta equation are determined. This article made it clearer for me: http://web.mit.edu/10.001/Web/Course%5FNotes/Differential%5FEquations%5FNotes/node5.html. Notice how (15) is the Taylor series expansion while (17) is the Runge-Kutta derivation. How is averaging derivatives up to the 4th order different from doing a simple euler integration with a smaller timestep? Mathematically it converges much faster than doing many Euler approximations. Of course, with enough Euler approximations we can gain equal accuracy to RK4, but the computational power needed doesn't justify using Euler.

  Read the article

• How do I copy a python function to a remote machine and then execute it?

  - by Hugh

  I'm trying to create a construct in Python 3 that will allow me to easily execute a function on a remote machine. Assuming I've already got a python tcp server that will run the functions it receives, running on the remote server, I'm currently looking at using a decorator like @execute_on(address, port) This would create the necessary context required to execute the function it is decorating and then send the function and context to the tcp server on the remote machine, which then executes it. Firstly, is this somewhat sane? And if not could you recommend a better approach? I've done some googling but haven't found anything that meets these needs. I've got a quick and dirty implementation for the tcp server and client so fairly sure that'll work. I can get a string representation the function (e.g. func) being passed to the decorator by import inspect string = inspect.getsource(func) which can then be sent to the server where it can be executed. The problem is, how do I get all of the context information that the function requires to execute? For example, if func is defined as follows, import MyModule def func(): result = MyModule.my_func() MyModule will need to be available to func either in the global context or funcs local context on the remote server. In this case that's relatively trivial but it can get so much more complicated depending on when and how import statements are used. Is there an easy and elegant way to do this in Python? The best I've come up with at the moment is using the ast library to pull out all import statements, using the inspect module to get string representations of those modules and then reconstructing the entire context on the remote server. Not particularly elegant and I can see lots of room for error. Thanks for your time

  Read the article

• ViewStateMode in ASP.Net 4.0

  - by sreejukg

  When asp.net introduced the concept of viewstate, it changed the way how developers maintain the state for the controls in a web page. Until then to keep the track of the control(in classic asp), it was the developer responsibility to manually assign the posted content before rendering the control again. Viewstate made allowed the developer to do it with ease. The developers are not bothered about how controls keep there state on post back. Viewstate is rendered to the browser as a hidden variable __viewstate. Since viewstate stores the values of all controls, as the number of controls in the page increases, the content of viewstate grows large. It causes some websites to load slowly. As developers we need viewstate, but actually we do not want this for all the controls in the page. Till asp.net 3.5, if viewstate is disabled from web.config (using <pages viewstate=”false”/> ..</pages>), then you can not enable it from the control level/page level. Both <%@ Page EnableViewState=”true”…. and <asp:textbox EnableViewState=”true” will not work in this case. Lot of developers demands for more control over viewstate. It will be useful if the developers are able to disable it for the entire page and enable it for only those controls that needed viewstate. With ASP.NET 4.0, this is possible, a happy news for the developers. This is achieved by introducing a new property called ViewStateMode. Let us see, What is ViewStateMode – Is a new property in asp.net 4.0, that allows developers to enable viewstate for individual control even if the parent has disabled it. This ViewStateMode property can contain either of three values Enabled- Enable view state for the control even if the parent control has view state disabled. Disabled - Disable view state for this control even if the parent control has view state enabled Inherit - Inherit the value of ViewStateMode from the parent, this is the default value. To disable view state for a page and to enable it for a specific control on the page, you can set the EnableViewState property of the page to true, then set the ViewStateMode property of the page to Disabled, and then set the ViewStateMode property of the control to Enabled. Find the example below. Page directive - <%@ Page Language="C#"  EnableViewState="True" ViewStateMode="Disabled" .......... %> Code for the control  - <asp:TextBox runat="server" ViewStateMode="Enabled" ............../> Now the viewstate will be disabled for the whole page, but enabled for the TextBox. ViewStateMode gives developers more control over the viewstate.

  Read the article

• How to deploy a report on a report server installed on a Windows7 machine?

  - by Sergio

  I need to deploy a report using Reporting services but i'm getting this error, using visual studio to deploy the report The permissions granted to user 'Domain\user' are insufficient for performing this operation Right now i'm the administrator of the machine, so why i'm getting i don't hace enough permissions? Note: The scenario is the following: Developing and deploying on a windows7 The report server is in the same machine. In conclusion, running all local. In spanish: Necesito hacer un deploy de un reporte en Reporting Services. Cuando corro el visual studio obtengo el siguiente error. Los permisos otorgados al usuario son insuficientes para realizar esta operación Actualmente soy el administrador de la máquina, entonces no entiendo porque aparece el error que no tengo suficientes permisos. Notas: Este es el escenario Desarrollando y haciendo el deploy en una máquina con windows7. El Report Server y el Visual Studio están en la misma máquina. En conclusión, todo lo corro localmente. Actualmente soy el administrador de la máquina, entonces no entiendo porque aparece el error que no tengo suficientes permisos.

  Read the article

• SVN Workflow - Chicken Before the Egg - Before merging V1 with V2, I need code from V1 to work on V2

  - by Jake

  Hi, Our distributed team (3 internal devs and 3+ external devs) use SVN to manage our codebase for a web site. We have a branch for each minor version (4.1.0, 4.1.1, 4.1.2, etc...). We have a trunk which we merge each version into when we do a release and publish to our site. An example of the problem we are having is thus: A new feature is added, lets call it "Ability to Create A Project" to 4.1.1. Another feature which depends on the one in 4.1.1 is scheduled to go in 4.1.2, called "Ability to Add Tasks to Projects". So, on Monday, we say 4.1.1 is 'closed' and needs to be tested. Our remote developers usually will start working on features/tickets for 4.1.2 at this point. Throughout the week we will test 4.1.1 and fix any bugs and commit them back to 4.1.1. Then, on Friday or so, we will tag 4.1.1, merge it with trunk, and finally, merge it with 4.1.2. But, for the 4-5 days we are testing, 4.1.2 doesn't have the code from 4.1.1 that some of the new features for 4.1.2 depend on. So a dev who is adding the "Ability to Add Tasks To Projects" feature, doesn't have the "Ability to Create a Project" feature to build upon, and has to do some file copy shenanigans to be able to keep working on it. What could/should we do to smooth out this process? P.S. Apologies if this question has been asked before - I did search but couldn't find what I'm looking for.

  Read the article

• How to create a Turing machine that takes a single digit decimal number from 0 - 9 and output the cu

  - by Julian

  I'm working on a project for a Turning machine but having problems conceptualizing the steps. f(x) = x^3, where x is a single digit between 0 - 9 inclusive. Based on my understanding I am to convert the number to binary but how do I find the cube of a number in binary. Also, how do I write the cube on the tape. So far I'm thinking I should create a state diagram that accepts the binary versions of 0-9 but what next?

  Read the article

< Previous Page | 147 148 149 150 151 152 153 154 155 156 157 158  | Next Page >