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• MVC & Windows Authentication

  - by TJ

  Changed the ValidateUser function  public bool ValidateUser(string userName, string password)         {             bool validation;             try             {                 LdapConnection ldc = new LdapConnection(new LdapDirectoryIdentifier((string)null, false, false));                 NetworkCredential nc = new NetworkCredential(userName, password, "domainname.com");                 ldc.Credential = nc;                 ldc.AuthType = AuthType.Negotiate;                 ldc.Bind(nc); // user has authenticated at this point, as the credentials were used to login to the dc.                  string myvar = ldc.SessionOptions.DomainName;                 validation = true;             }             catch (LdapException)             {                 validation = false;             }             return validation;         }

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• Most efficient way to implement delta time

  - by Starkers

  Here's one way to implement delta time: /// init /// var duration = 5000, currentTime = Date.now(); // and create cube, scene, camera ect ////// function animate() { /// determine delta /// var now = Date.now(), deltat = now - currentTime, currentTime = now, scalar = deltat / duration, angle = (Math.PI * 2) * scalar; ////// /// animate /// cube.rotation.y += angle; ////// /// update /// requestAnimationFrame(render); ////// } Could someone confirm I know how it works? Here what I think is going on: Firstly, we set duration at 5000, which how long the loop will take to complete in an ideal world. With a computer that is slow/busy, let's say the animation loop takes twice as long as it should, so 10000: When this happens, the scalar is set to 2.0: scalar = deltat / duration scalar = 10000 / 5000 scalar = 2.0 We now times all animation by twice as much: angle = (Math.PI * 2) * scalar; angle = (Math.PI * 2) * 2.0; angle = (Math.PI * 4) // which is 2 rotations When we do this, the cube rotation will appear to 'jump', but this is good because the animation remains real-time. With a computer that is going too quickly, let's say the animation loop takes half as long as it should, so 2500: When this happens, the scalar is set to 0.5: scalar = deltat / duration scalar = 2500 / 5000 scalar = 0.5 We now times all animation by a half: angle = (Math.PI * 2) * scalar; angle = (Math.PI * 2) * 0.5; angle = (Math.PI * 1) // which is half a rotation When we do this, the cube won't jump at all, and the animation remains real time, and doesn't speed up. However, would I be right in thinking this doesn't alter how hard the computer is working? I mean it still goes through the loop as fast as it can, and it still has render the whole scene, just with different smaller angles! So this a bad way to implement delta time, right? Now let's pretend the computer is taking exactly as long as it should, so 5000: When this happens, the scalar is set to 1.0: angle = (Math.PI * 2) * scalar; angle = (Math.PI * 2) * 1; angle = (Math.PI * 2) // which is 1 rotation When we do this, everything is timsed by 1, so nothing is changed. We'd get the same result if we weren't using delta time at all! My questions are as follows Mostly importantly, have I got the right end of the stick here? How do we know to set the duration to 5000 ? Or can it be any number? I'm a bit vague about the "computer going too quickly". Is there a way loop less often rather than reduce the animation steps? Seems like a better idea. Using this method, do all of our animations need to be timesed by the scalar? Do we have to hunt down every last one and times it? Is this the best way to implement delta time? I think not, due to the fact the computer can go nuts and all we do is divide each animation step and because we need to hunt down every step and times it by the scalar. Not a very nice DSL, as it were. So what is the best way to implement delta time? Below is one way that I do not really get but may be a better way to implement delta time. Could someone explain please? // Globals INV_MAX_FPS = 1 / 60; frameDelta = 0; clock = new THREE.Clock(); // In the animation loop (the requestAnimationFrame callback)… frameDelta += clock.getDelta(); // API: "Get the seconds passed since the last call to this method." while (frameDelta >= INV_MAX_FPS) { update(INV_MAX_FPS); // calculate physics frameDelta -= INV_MAX_FPS; } How I think this works: Firstly we set INV_MAX_FPS to 0.01666666666 How we will use this number number does not jump out at me. We then intialize a frameDelta which stores how long the last loop took to run. Come the first loop frameDelta is not greater than INV_MAX_FPS so the loop is not run (0 = 0.01666666666). So nothing happens. Now I really don't know what would cause this to happen, but let's pretend that the loop we just went through took 2 seconds to complete: We set frameDelta to 2: frameDelta += clock.getDelta(); frameDelta += 2.00 Now we run an animation thanks to update(0.01666666666). Again what is relevance of 0.01666666666?? And then we take away 0.01666666666 from the frameDelta: frameDelta -= INV_MAX_FPS; frameDelta = frameDelta - INV_MAX_FPS; frameDelta = 2 - 0.01666666666 frameDelta = 1.98333333334 So let's go into the second loop. Let's say it took 2(? Why not 2? Or 12? I am a bit confused): frameDelta += clock.getDelta(); frameDelta = frameDelta + clock.getDelta(); frameDelta = 1.98333333334 + 2 frameDelta = 3.98333333334 This time we enter the while loop because 3.98333333334 = 0.01666666666 We run update We take away 0.01666666666 from frameDelta again: frameDelta -= INV_MAX_FPS; frameDelta = frameDelta - INV_MAX_FPS; frameDelta = 3.98333333334 - 0.01666666666 frameDelta = 3.96666666668 Now let's pretend the loop is super quick and runs in just 0.1 seconds and continues to do this. (Because the computer isn't busy any more). Basically, the update function will be run, and every loop we take away 0.01666666666 from the frameDelta untill the frameDelta is less than 0.01666666666. And then nothing happens until the computer runs slowly again? Could someone shed some light please? Does the update() update the scalar or something like that and we still have to times everything by the scalar like in the first example?

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• Why does waking from hibernate take nearly ten minutes on 11.10?

  - by Shane O'Connor

  Im running 11.10 64bit on a Dell XPS 15 L502x laptop. It uses an i5 proc and has 16Gb ram. Whenever I close the lid on the laptop I have it set to hibernate as I want to continue whatever I was previously running. Generally that is simple text editing, so my mem usage would normally be only a Gb or 2. When I open the lid and it resumes from Hibernation, it takes up to ten minutes to do so. Extremely frustrating. Is there anything I can do to make hibernate function properly. On windows it used to wake from Hibernation in less than 30 seconds. Its really frustrating and souring my experience with Ubuntu. Any help would be gratefully appreciated! Thanks guys/gals! S

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• How often do CPUs make calculation errors?

  - by veryfoolish

  In Dijkstra's Notes on Structured Programming he talks a lot about the provability of computer programs as abstract entities. As a corollary, he remarks how testing isn't enough. E.g., he points out the fact that it would be impossible to test a multiplication function f(x,y) = x*y for any large values of x and y across the entire ranges of x and y. My question concerns his misc. remarks on "lousy hardware". I know the essay was written in the 1970s when computer hardware was less reliable, but computers still aren't perfect, so they must make calculation mistakes sometimes. Does anybody know how often this happens or if there are any statistics on this?

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• Physics System ignores collision in some rare cases

  - by Gajoo

  I've been developing a simple physics engine for my game. since the game physics is very simple I've decided to increase accuracy a little bit. Instead of formal integration methods like fourier or RK4, I'm directly computing the results after delta time "dt". based on the very first laws of physics : dx = 0.5 * a * dt^2 + v0 * dt dv = a * dt where a is acceleration and v0 is object's previous velocity. Also to handle collisions I've used a method which is somehow different from those I've seen so far. I'm detecting all the collision in the given time frame, stepping the world forward to the nearest collision, resolving it and again check for possible collisions. As I said the world consist of very simple objects, so I'm not loosing any performance due to multiple collision checking. First I'm checking if the ball collides with any walls around it (which is working perfectly) and then I'm checking if it collides with the edges of the walls (yellow points in the picture). the algorithm seems to work without any problem except some rare cases, in which the collision with points are ignored. I've tested everything and all the variables seem to be what they should but after leaving the system work for a minute or two the system the ball passes through one of those points. Here is collision portion of my code, hopefully one of you guys can give me a hint where to look for a potential bug! void PhysicalWorld::checkForPointCollision(Vec2 acceleration, PhysicsComponent& ball, Vec2& collisionNormal, float& collisionTime, Vec2 target) { // this function checks if there will be any collision between a circle and a point // ball contains informations about the circle (it's current velocity, position and radius) // collisionNormal is an output variable // collisionTime is also an output varialbe // target is the point I want to check for collisions Vec2 V = ball.mVelocity; Vec2 A = acceleration; Vec2 P = ball.mPosition - target; float wallWidth = mMap->getWallWidth() / (mMap->getWallWidth() + mMap->getHallWidth()) / 2; float r = ball.mRadius / (mMap->getWallWidth() + mMap->getHallWidth()); // r is ball radius scaled to match actual rendered object. if (A.any()) // todo : I need to first correctly solve the collisions in case there is no acceleration return; if (V.any()) // if object is not moving there will be no collisions! { float D = P.x * V.y - P.y * V.x; float Delta = r*r*V.length2() - D*D; if(Delta < eps) return; Delta = sqrt(Delta); float sgnvy = V.y > 0 ? 1: (V.y < 0?-1:0); Vec2 c1(( D*V.y+sgnvy*V.x*Delta) / V.length2(), (-D*V.x+fabs(V.y)*Delta) / V.length2()); Vec2 c2(( D*V.y-sgnvy*V.x*Delta) / V.length2(), (-D*V.x-fabs(V.y)*Delta) / V.length2()); float t1 = (c1.x - P.x) / V.x; float t2 = (c2.x - P.x) / V.x; if(t1 > eps && t1 <= collisionTime) { collisionTime = t1; collisionNormal = c1; } if(t2 > eps && t2 <= collisionTime) { collisionTime = t2; collisionNormal = c2; } } } // this function should step the world forward by dt. it doesn't check for collision of any two balls (components) // it just checks if there is a collision between the current component and 4 points forming a rectangle around it. void PhysicalWorld::step(float dt) { for (unsigned i=0;i<mObjects.size();i++) { PhysicsComponent &current = *mObjects[i]; Vec2 acceleration = current.mForces * current.mInvMass; float rt=dt; // stores how much more the world should advance while(rt > eps) { float collisionTime = rt; Vec2 collisionNormal = Vec2(0,0); float halfWallWidth = mMap->getWallWidth() / (mMap->getWallWidth() + mMap->getHallWidth()) / 2; // we check if there is any collision with any of those 4 points around the ball // if there is a collision both collisionNormal and collisionTime variables will change // after these functions collisionTime will be exactly the value of nearest collision (if any) // and if there was, collisionNormal will report in which direction the ball should return. checkForPointCollision(acceleration,current,collisionNormal,collisionTime,Vec2(floor(current.mPosition.x) + halfWallWidth,floor(current.mPosition.y) + halfWallWidth)); checkForPointCollision(acceleration,current,collisionNormal,collisionTime,Vec2(floor(current.mPosition.x) + halfWallWidth, ceil(current.mPosition.y) - halfWallWidth)); checkForPointCollision(acceleration,current,collisionNormal,collisionTime,Vec2( ceil(current.mPosition.x) - halfWallWidth,floor(current.mPosition.y) + halfWallWidth)); checkForPointCollision(acceleration,current,collisionNormal,collisionTime,Vec2( ceil(current.mPosition.x) - halfWallWidth, ceil(current.mPosition.y) - halfWallWidth)); // either if there is a collision or if there is not we step the forward since we are sure there will be no collision before collisionTime current.mPosition += collisionTime * (collisionTime * acceleration * 0.5 + current.mVelocity); current.mVelocity += collisionTime * acceleration; // if the ball collided with anything collisionNormal should be at least none zero in one of it's axis if (collisionNormal.any()) { collisionNormal *= Dot(collisionNormal, current.mVelocity) / collisionNormal.length2(); current.mVelocity -= 2 * collisionNormal; // simply reverse velocity along collision normal direction } rt -= collisionTime; } // reset all forces for current object so it'll be ready for later game event current.mForces.zero(); } }

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• Is Java easy decompilation a factor worth considering

  - by Sandra G

  We are considering the programming language for a desktop application with extended GUI use (tables, windows) and heavy database use. We considered Java for use however the fact that it can be decompiled back very easily into source code is holding us back. There are of course many obfuscators available however they are just that: obfuscators. The only obfuscation worth doing we got was stripping function and variables names into meaningless letters and numbers so that at least stealing code and renaming it back into something meaningful is too much work and we are 100% sure it is not reversible back in any automated way. However as it concerns to protecting internals (like password hashes or sensible variables content) we found obfuscators really lacking. Is there any way to make Java applications as hard to decode as .exe counterparts? And is it a factor to consider when deciding whether to develop in Java a desktop application?

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• Is this the right strategy to convert an in-level order binary tree to a doubly linked list?

  - by Ankit Soni

  So I recently came across this question - Make a function that converts a in-level-order binary tree into a doubly linked list. Apparently, it's a common interview question. This is the strategy I had - Simply do a pre-order traversal of the tree, and instead of returning a node, return a list of nodes, in the order in which you traverse them. i.e return a list, and append the current node to the list at each point. For the base case, return the node itself when you are at a leaf. so you would say left = recursive_function(node.left) right = recursive_function(node.right) return(left.append(node.data)).append(right);` Is this the right approach?

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• Using the full tty real estate with sqlplus

  - by katsumii

  I believe 'rlwrap' is widely used for adding 'sqlplus' the history function and command line editing. 'rlwrap' has other functions and here's my kludgy alias to force sqlplus to use the full real estate of yourtty. Be it PuTTy session from Windows or Linux gnome terminal. $ declare -f sqlplus sqlplus () { PRE_TEXT=$(resize |sed -n "1s/COLUMNS=/set linesize /p;2s/LINES=/set pagesize /p"|while read line; do printf "%s \ " "$line";done); if [ -z "$1" ]; then rlwrap -m -P "$PRE_TEXT" sqlplus /nolog; else if ! echo $1 | grep '^-' > /dev/null; then rlwrap -m -P "$PRE_TEXT connect $*" sqlplus /nolog; else command sqlplus $*; fi; fi }

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• Scripting Part 1

  - by rbishop

  Dynamic Scripting is a large topic, so let me get a couple of things out of the way first. If you aren't familiar with JavaScript, I can suggest CodeAcademy's JavaScript series. There are also many other websites and books that cover JavaScript from every possible angle.The second thing we need to deal with is JavaScript as a programming language versus a JavaScript environment running in a web browser. Many books, tutorials, and websites completely blur these two together but they are in fact completely separate. What does this really mean in relation to DRM? Since DRM isn't a web browser, there are no document, window, history, screen, or location objects. There are no events like mousedown or click. Trying to call alert('hello!') in DRM will just cause an error. Those concepts are all related to an HTML document (web page) and are part of the Browser Object Model or Document Object Model. DRM has its own object model that exposes DRM-related objects. In practice, feel free to use those sorts of tutorials or practice within your browser; Many of the concepts are directly translatable to writing scripts in DRM. Just don't try to call document.getElementById in your property definition!I think learning by example tends to work the best, so let's try getting a list of all the unique property values for a given node and its children. var uniqueValues = {}; var childEnumerator = node.GetChildEnumerator(); while(childEnumerator.MoveNext()) { var propValue = childEnumerator.GetCurrent().PropValue("Custom.testpropstr1"); print(propValue); if(propValue != null && propValue != '' && !uniqueValues[propValue]) uniqueValues[propValue] = true; } var result = ''; for(var value in uniqueValues){ result += "Found value " + value + ","; } return result;  Now lets break this down piece by piece. var uniqueValues = {}; This declares a variable and initializes it as a new empty Object. You could also have written var uniqueValues = new Object(); Why use an object here? JavaScript objects can also function as a list of keys and we'll use that later to store each property value as a key on the object. var childEnumerator = node.GetChildEnumerator(); while(childEnumerator.MoveNext()) { This gets an enumerator for the node's children. The enumerator allows us to loop through the children one by one. If we wanted to get a filtered list of children, we would instead use ChildrenWith(). When we reach the end of the child list, the enumerator will return false for MoveNext() and that will stop the loop. var propValue = childEnumerator.GetCurrent().PropValue("Custom.testpropstr1"); print(propValue); if(propValue != null && propValue != '' && !uniqueValues[propValue]) uniqueValues[propValue] = true; } This gets the node the enumerator is currently pointing at, then calls PropValue() on it to get the value of a property. We then make sure the prop value isn't null or the empty string, then we make sure the value doesn't already exist as a key. Assuming it doesn't we add it as a key with a value (true in this case because it makes checking for an existing value faster when the value exists). A quick word on the print() function. When viewing the prop grid, running an export, or performing normal DRM operations it does nothing. If you have a lot of print() calls with complicated arguments it can slow your script down slightly, but otherwise has no effect. But when using the script editor, all the output of print() will be shown in the Warnings area. This gives you an extremely useful debugging tool to see what exactly a script is doing. var result = ''; for(var value in uniqueValues){ result += "Found value " + value + ","; } return result; Now we build a string by looping through all the keys in uniqueValues and adding that value to our string. The last step is to simply return the result. Hopefully this small example demonstrates some of the core Dynamic Scripting concepts. Next time, we can try checking for node references in other hierarchies to see if they are using duplicate property values.

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• Will Unity allow users to change the color/appearance of the top-Panel?

  - by Sam

  I'm very excited by the functional design principles and keyboard shortcuts that are being implemented for Unity. And function of use is more important to me than looks. However, after experiencing the aesthetic beauty of the display of the top panel in gnome-shell, I was wondering if users would be able to alter the color of Unity's top panel? IMHO it does not look as good as the gnome-shell implementation (or mac OS X/iPad). I think if an alternate color/appearance were chosen for the panel, it would make a big difference aesthetically. Is there a way to make it Black like gnome-shell? Or are the color choices limited to theme-designs as pointed out in this answer? For efficiency and clarity, the Panel should be better differentiated from application controls. The panel should be a different color because it has a "constant (always present) state," unlike application controls. For contrast and easy-recognition, I would like to make the Panel black (like gnome-shell) but make the application controls (e.g., those of Firefox) "Inverted"

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• gvim configuration does not work like it should

  - by ganjan

  Hi. I have a little problem with my vim config. This what I got in my home/user/.gvimrc syntax enable "Enable syntax hl colorscheme peaksea set background=dark set gfn=Inconsolata:h11 set nonu set history=1000 set scrolloff=3 set number " turn on line numbers " Save a global session file on session close nmap SQ <ESC>:mksession! ~/.vim/session/Session.vim<CR>:wqa<CR> function! RestoreSession() if argc() == 0 "vim called without arguments execute 'source ~/.vim/session/Session.vim' end endfunction autocmd VimEnter * call RestoreSession() The colorsheme work, but the font has way to much spacing. Every sentence is twice as long. I installed the Inconsolata font and I have the same config on my windows 7 box and it works fine.

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• Error in my Separating Axis Theorem collision code

  - by Holly

  The only collision experience i've had was with simple rectangles, i wanted to find something that would allow me to define polygonal areas for collision and have been trying to make sense of SAT using these two links Though i'm a bit iffy with the math for the most part i feel like i understand the theory! Except my implementation somewhere down the line must be off as: (excuse the hideous font) As mentioned above i have defined a CollisionPolygon class where most of my theory is implemented and then have a helper class called Vect which was meant to be for Vectors but has also been used to contain a vertex given that both just have two float values. I've tried stepping through the function and inspecting the values to solve things but given so many axes and vectors and new math to work out as i go i'm struggling to find the erroneous calculation(s) and would really appreciate any help. Apologies if this is not suitable as a question! CollisionPolygon.java: package biz.hireholly.gameplay; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import biz.hireholly.gameplay.Types.Vect; public class CollisionPolygon { Paint paint; private Vect[] vertices; private Vect[] separationAxes; int x; int y; CollisionPolygon(Vect[] vertices){ this.vertices = vertices; //compute edges and separations axes separationAxes = new Vect[vertices.length]; for (int i = 0; i < vertices.length; i++) { // get the current vertex Vect p1 = vertices[i]; // get the next vertex Vect p2 = vertices[i + 1 == vertices.length ? 0 : i + 1]; // subtract the two to get the edge vector Vect edge = p1.subtract(p2); // get either perpendicular vector Vect normal = edge.perp(); // the perp method is just (x, y) => (-y, x) or (y, -x) separationAxes[i] = normal; } paint = new Paint(); paint.setColor(Color.RED); } public void draw(Canvas c, int xPos, int yPos){ for (int i = 0; i < vertices.length; i++) { Vect v1 = vertices[i]; Vect v2 = vertices[i + 1 == vertices.length ? 0 : i + 1]; c.drawLine( xPos + v1.x, yPos + v1.y, xPos + v2.x, yPos + v2.y, paint); } } public void update(int xPos, int yPos){ x = xPos; y = yPos; } /* consider changing to a static function */ public boolean intersects(CollisionPolygon p){ // loop over this polygons separation exes for (Vect axis : separationAxes) { // project both shapes onto the axis Vect p1 = this.minMaxProjection(axis); Vect p2 = p.minMaxProjection(axis); // do the projections overlap? if (!p1.overlap(p2)) { // then we can guarantee that the shapes do not overlap return false; } } // loop over the other polygons separation axes Vect[] sepAxesOther = p.getSeparationAxes(); for (Vect axis : sepAxesOther) { // project both shapes onto the axis Vect p1 = this.minMaxProjection(axis); Vect p2 = p.minMaxProjection(axis); // do the projections overlap? if (!p1.overlap(p2)) { // then we can guarantee that the shapes do not overlap return false; } } // if we get here then we know that every axis had overlap on it // so we can guarantee an intersection return true; } /* Note projections wont actually be acurate if the axes aren't normalised * but that's not necessary since we just need a boolean return from our * intersects not a Minimum Translation Vector. */ private Vect minMaxProjection(Vect axis) { float min = axis.dot(new Vect(vertices[0].x+x, vertices[0].y+y)); float max = min; for (int i = 1; i < vertices.length; i++) { float p = axis.dot(new Vect(vertices[i].x+x, vertices[i].y+y)); if (p < min) { min = p; } else if (p > max) { max = p; } } Vect minMaxProj = new Vect(min, max); return minMaxProj; } public Vect[] getSeparationAxes() { return separationAxes; } public Vect[] getVertices() { return vertices; } } Vect.java: package biz.hireholly.gameplay.Types; /* NOTE: Can also be used to hold vertices! Projections, coordinates ect */ public class Vect{ public float x; public float y; public Vect(float x, float y){ this.x = x; this.y = y; } public Vect perp() { return new Vect(-y, x); } public Vect subtract(Vect other) { return new Vect(x - other.x, y - other.y); } public boolean overlap(Vect other) { if(y > other.x && other.y > x){ return true; } return false; } /* used specifically for my SAT implementation which i'm figuring out as i go, * references for later.. * http://www.gamedev.net/page/resources/_/technical/game-programming/2d-rotated-rectangle-collision-r2604 * http://www.codezealot.org/archives/55 */ public float scalarDotProjection(Vect other) { //multiplier = dot product / length^2 float multiplier = dot(other) / (x*x + y*y); //to get the x/y of the projection vector multiply by x/y of axis float projX = multiplier * x; float projY = multiplier * y; //we want to return the dot product of the projection, it's meaningless but useful in our SAT case return dot(new Vect(projX,projY)); } public float dot(Vect other){ return (other.x*x + other.y*y); } }

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• Predicate delegate in C#

  - by Jalpesh P. Vadgama

  I am writing few post on different type of delegates and and this post also will be part of it. In this post I am going to write about Predicate delegate which is available from C# 2.0. Following is list of post that I have written about delegates. Delegates in C#. Multicast delegates in C#. Func delegate in C#. Action delegate in C#. Predicate delegate in C#: As per MSDN predicate delegate is a pointer to a function that returns true or false and takes generics types as argument. It contains following signature. Predicate<T> – where T is any generic type and this delegate will always return Boolean value. The most common use of a predicate delegate is to searching items in array or list. So let’s take a simple example. Following is code for that. Read More

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• Backlit keyboard on Toshiba Satellite P755-S5184 doesn't work in Ubuntu 12.04

  - by chrisabner23

  I have the keyboard backlight turned on in bios to timer setting (1 second). When laptop boots the backlight works, but once ubuntu begins to load the backlights turn off. There is a function key combo that is supposed to turn it on (Fn +Z), hitting that brings up a notification balloon showing the backlit keyboard icon but it is grayed out. I tried using KeyTouch to try and get the backlight working but my laptop model isn't on the list. I'm new to Ubuntu, and have been searching the web and can't seem to find any answers that will work for my particular situation. Any information would be MUCH appreciated. Thanks!

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• ROracle support for TimesTen In-Memory Database

  - by Sam Drake

  Today's guest post comes from Jason Feldhaus, a Consulting Member of Technical Staff in the TimesTen Database organization at Oracle.  He shares with us a sample session using ROracle with the TimesTen In-Memory database.  Beginning in version 1.1-4, ROracle includes support for the Oracle Times Ten In-Memory Database, version 11.2.2. TimesTen is a relational database providing very fast and high throughput through its memory-centric architecture.  TimesTen is designed for low latency, high-volume data, and event and transaction management. A TimesTen database resides entirely in memory, so no disk I/O is required for transactions and query operations. TimesTen is used in applications requiring very fast and predictable response time, such as real-time financial services trading applications and large web applications. TimesTen can be used as the database of record or as a relational cache database to Oracle Database. ROracle provides an interface between R and the database, providing the rich functionality of the R statistical programming environment using the SQL query language. ROracle uses the OCI libraries to handle database connections, providing much better performance than standard ODBC.The latest ROracle enhancements include: Support for Oracle TimesTen In-Memory Database Support for Date-Time using R's POSIXct/POSIXlt data types RAW, BLOB and BFILE data type support Option to specify number of rows per fetch operation Option to prefetch LOB data Break support using Ctrl-C Statement caching support Times Ten 11.2.2 contains enhanced support for analytics workloads and complex queries: Analytic functions: AVG, SUM, COUNT, MAX, MIN, DENSE_RANK, RANK, ROW_NUMBER, FIRST_VALUE and LAST_VALUE Analytic clauses: OVER PARTITION BY and OVER ORDER BY Multidimensional grouping operators: Grouping clauses: GROUP BY CUBE, GROUP BY ROLLUP, GROUP BY GROUPING SETS Grouping functions: GROUP, GROUPING_ID, GROUP_ID WITH clause, which allows repeated references to a named subquery block Aggregate expressions over DISTINCT expressions General expressions that return a character string in the source or a pattern within the LIKE predicate Ability to order nulls first or last in a sort result (NULLS FIRST or NULLS LAST in the ORDER BY clause) Note: Some functionality is only available with Oracle Exalytics, refer to the TimesTen product licensing document for details. Connecting to TimesTen is easy with ROracle. Simply install and load the ROracle package and load the driver. > install.packages("ROracle") > library(ROracle) Loading required package: DBI > drv <- dbDriver("Oracle") Once the ROracle package is installed, create a database connection object and connect to a TimesTen direct driver DSN as the OS user. > conn <- dbConnect(drv, username ="", password="", dbname = "localhost/SampleDb_1122:timesten_direct") You have the option to report the server type - Oracle or TimesTen? > print (paste ("Server type =", dbGetInfo (conn)$serverType)) [1] "Server type = TimesTen IMDB" To create tables in the database using R data frame objects, use the function dbWriteTable. In the following example we write the built-in iris data frame to TimesTen. The iris data set is a small example data set containing 150 rows and 5 columns. We include it here not to highlight performance, but so users can easily run this example in their R session. > dbWriteTable (conn, "IRIS", iris, overwrite=TRUE, ora.number=FALSE) [1] TRUE Verify that the newly created IRIS table is available in the database. To list the available tables and table columns in the database, use dbListTables and dbListFields, respectively. > dbListTables (conn) [1] "IRIS" > dbListFields (conn, "IRIS") [1] "SEPAL.LENGTH" "SEPAL.WIDTH" "PETAL.LENGTH" "PETAL.WIDTH" "SPECIES" To retrieve a summary of the data from the database we need to save the results to a local object. The following call saves the results of the query as a local R object, iris.summary. The ROracle function dbGetQuery is used to execute an arbitrary SQL statement against the database. When connected to TimesTen, the SQL statement is processed completely within main memory for the fastest response time. > iris.summary <- dbGetQuery(conn, 'SELECT SPECIES, AVG ("SEPAL.LENGTH") AS AVG_SLENGTH, AVG ("SEPAL.WIDTH") AS AVG_SWIDTH, AVG ("PETAL.LENGTH") AS AVG_PLENGTH, AVG ("PETAL.WIDTH") AS AVG_PWIDTH FROM IRIS GROUP BY ROLLUP (SPECIES)') > iris.summary SPECIES AVG_SLENGTH AVG_SWIDTH AVG_PLENGTH AVG_PWIDTH 1 setosa 5.006000 3.428000 1.462 0.246000 2 versicolor 5.936000 2.770000 4.260 1.326000 3 virginica 6.588000 2.974000 5.552 2.026000 4 <NA> 5.843333 3.057333 3.758 1.199333 Finally, disconnect from the TimesTen Database. > dbCommit (conn) [1] TRUE > dbDisconnect (conn) [1] TRUE We encourage you download Oracle software for evaluation from the Oracle Technology Network. See these links for our software: Times Ten In-Memory Database,  ROracle.  As always, we welcome comments and questions on the TimesTen and  Oracle R technical forums.

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• What data is available regarding cowboy coding?

  - by Christine

  I'm not a programmer; I'm a freelance writer and researcher. I have a client who is looking for stats on certain "threats" to the apps market in general (not any specific app store). One of them is cowboy coding: specifically, he wants to see numbers regarding how many apps have failed to function as intended/crashed/removed because of errors made by, in essence, sloppy coding. Note that I'm not here to debate the merits of cowboy coding, and whether or not it is sloppy. Is there any data about this type of development?

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• Can an object oriented program be seen as a Finite State Machine?

  - by Peretz

  This might be a philosophical/fundamental question, but I just want to clarify it. In my understanding a Finite State Machine is a way of modeling a system in which the system's output will not only depend on the current inputs, but also the current state of the system. Additionally, as the name suggests it, a finite state machine can be segmented in a finite N number of states with its respective state and behavior. If this is correct, shouldn't every single object with data and function members be a state in our object oriented model, making any object oriented design a finite state machine? If that is not the interpretation of a FSM in object design, what exactly people mean when they implement a FSM in software? am I missing something? Thanks

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• What can procs and lambdas do that functions can't in ruby

  - by SecurityGate

  I've been working in Ruby for the last couple weeks, and I've come to the subject of procs, lambdas and blocks. After reading a fair share of examples from a variety of sources, I don't how they're much different from small, specialized functions. It's entirely possible that the examples I've read aren't showing the power behind procs and lambdas. def zero_function(x) x = x.to_s if x.length == 1 return x = "0" + x else return x end end zero_lambda = lambda {|x| x = x.to_s if x.length == 1 return x = "0" + x else return x end } zero_proc = Proc.new {|x| x = x.to_s if x.length == 1 puts x = "0" + x else puts x end } puts zero_function(4) puts zero_lambda.call(3) zero_proc.call(2) This function, proc, and lambda do the exact same thing, just slightly different. Is there any reason to choose one over another?

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• Can't change brightness on Toshiba l755 laptop

  - by albert

  I have a Toshiba l755 laptop, and I installed 12.04 64bit on it. The default brightness of the laptop is set to maximum value, and I can't change it. If I go to Configuration ? Brightness, the brightness doesn't change and neither does pressing the function keys. I tried changing some parameters of grub file, setting GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi=Linux acpi_backlight=vendor". When changing the brightness from configuration, the value of /sys/class/backlight/toshiba/brightess changes, but screen remains the same. If I use the key functions, it changes the "actual_brightness" files. I don't know what else can I do, any suggestions?

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• Better than dynamic SQL - How to pass a list of comma separated IDs into a stored proc

  - by Rodney Vinyard

  Better than dynamic SQL - How to pass a list of comma separated IDs into a stored proc:     Derived form "Method 6" from a great article: ·         How to pass a list of values or array to SQL Server stored procedure ·          http://vyaskn.tripod.com/passing_arrays_to_stored_procedures.htm     Create PROCEDURE [dbo].[GetMyTable_ListByCommaSepReqIds] (@CommaSepReqIds varchar(500))   AS   BEGIN   select * from MyTable q               JOIN               dbo.SplitStringToNumberTable(@CommaSepReqIds) AS s               ON               q.MyTableId = s.ID End     ALTER FUNCTION [dbo].[SplitStringToNumberTable] (        @commaSeparatedList varchar(500) ) RETURNS @outTable table (        ID int ) AS BEGIN        DECLARE @parsedItem varchar(10), @Pos int          SET @commaSeparatedList = LTRIM(RTRIM(@commaSeparatedList))+ ','        SET @commaSeparatedList = REPLACE(@commaSeparatedList, ' ', '')        SET @Pos = CHARINDEX(',', @commaSeparatedList, 1)          IF REPLACE(@commaSeparatedList, ',', '') <> ''        BEGIN               WHILE @Pos > 0               BEGIN                      SET @parsedItem = LTRIM(RTRIM(LEFT(@commaSeparatedList, @Pos - 1)))                      IF @parsedItem <> ''                            BEGIN                                   INSERT INTO @outTable (ID)                                   VALUES (CAST(@parsedItem AS int)) --Use Appropriate conversion                            END                            SET @commaSeparatedList = RIGHT(@commaSeparatedList, LEN(@commaSeparatedList) - @Pos)                            SET @Pos = CHARINDEX(',', @commaSeparatedList, 1)               END        END           RETURN END

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• Get Real Multitasking on Android With These 8 Floating Apps

  - by Chris Hoffman

  Android has decent multitasking, but the missing piece of the puzzle is the ability to have multiple apps on-screen at the same time – particularly useful on a larger tablet. Floating apps fill this need. Floating apps function as always-on-top windows, allowing you to watch videos, browse the web, take notes, or do other things while using another app. They demonstrate how Android’s interface is more flexible than iOS and the Modern UI in Windows. Secure Yourself by Using Two-Step Verification on These 16 Web Services How to Fix a Stuck Pixel on an LCD Monitor How to Factory Reset Your Android Phone or Tablet When It Won’t Boot

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• Change hotkeys/shortcut keys for volume control

  - by Daniel le Rouge

  I need to change the hotkeys for volume control, since I suffer from a bug, which disallows me to use the standard function hotkeys of my notebook. Since I have updated I to Oneiric, I am not able to change the settings for the hotkeys. It is neither possible in system settings nor in gconf-editor. Current buggy configuration: Volume mute: Fn + F3 Volume down: Fn + F4 Volume up: Fn + F5 Desired configuration: Volume mute: Ctrl + F3 Volume down: Ctrl + F4 Volume up: Ctrl + F5 If you need further information, I will be happy to provide it. I tried to overwrite the standard settings by creating a new one in the “Custom shortcuts” category. Even this attempt is unsuccessful. Is there a possibility to access this menu as root?

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• How come verification does not include actual testing?

  - by user970696

  Having read a lot about this topic, I still did not get it. Verification should prove that you are building the product right, while validation you build the right product. But only static techniques are mentioned as being verification methods (code reviews, requirements checks...). But how can you say if its implemented correctly if you do not test it? It is said that verification checks e.g. code for its correctnes. Verification - ensure that the product meet specified requirements. Again, if the function is specified to work somehow, only by testing I can say that it does. Could anyone explain this to me please? EDIT: As Wiki says: Verification:Preparing of the test cases (based on the analysis of the requireemnts) Validation: Running of the test cases

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• In-depth Coverage for Oracle Workflow

  - by Steven Chan (Oracle Development)

  I'm lucky to work with many talented people in the Applications Technology Group, and many of them contribute articles to this blog.  Some team members have their own blogs.  If you work with Oracle Workflow, here's one that you should be following: Oracle E-Business Suite - Workflow This blog is updated every few months by our development team with in-depth technical articles about Oracle Workflow-related topics.  For example, articles posted there include: Implementing a post-notification function to perform custom validation E-Business Suite Proactive Support - Workflow Analyzer Asynchronous Business Event Subscriptions - Troubleshooting Tips Oracle E-Busienss Suite RCD - Applications Technology Releases 12.1 and 12.2 SMTP Authentication Feature in R12.1.3 Configurable User LOV in Worklist UI Oracle Business Event and Subsciptions Execution Flow Understanding AQs in Workflow SSL in Oracle Workflow Leveraging Oracle Workflow for Declarative PageFlow If you have suggestions about Workflow topics that you'd like to see covered there, drop them a line.

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• MVC helper functions business logic

  - by Menelaos Vergis

  I am creating some helper functions (mvc.net) for creating common controls that I need in almost every project such as alert boxes, dialogs etc. If these do not contain any business logic and it's just client side code (html, js) then it's ok. My problem arises when I need some business logic behind this helper. I want to create a 'rate my (web) application' control that will be visible every 3 days and the user may hide it for now, navigate to rate link or hide it for ever. To do this I need some sort of database access and a code that acts as business logic. Normally I would use a controller for this, with my DI and everything, but I don't know where to put this code now. This should be placed in the helper function or in a controller that responds objects instead of ActionResults?

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