I have some spare keys that I want to trade for an unusual hat.   What are the prices of all the unusual hats? And is there an unusual within the price range of 5-10 keys?
As someone who doesn't play Team Fortress 2, I occasionally get people asking me to trade, but I have no idea what's a "fair" price for these items. I don't really get this whole trading thing (I've seen people ask for "63 buds", I have zero idea what that means), but I don't want to get ripped off.   Some recent  examples would be:        How can I figure out how much an item is worth? What "lingo" do I need to know in order to trade?
Evaluating indefinite integrals of the form $\int \frac{x^2 \,dx}{a x^5 + b}$ Evaluate the indefinite integral   $$\int \frac{x^2 \,dx}{a x^5 + b},$$   for real parameters $a, b \neq 0$.   No apparent substitutions simplify the expression (if the exponent of $x$ were an integral multiple of $3$, this would suggest the substitution $u = x^3$, $du = 3 x^2 \,dx$, but the exponent is not). Applying integration by parts with $u = a x^5 + b$, $dv = x^2 dx$ is straightforward, but it produces an integrand with a much larger degree in the denominator and so appears only to make the situation worse. Applying integration by parts instead with $dw = \frac{x^k dx}{a x^5 + b}$ results in integrating $\frac{x^k dx}{a x^5 + b}$, which except when $k \equiv 4 \pmod 5$ (which doesn't appear immediately fruitful), doesn't appear much easier than the given integral. Iterating over Java collections in Scala I'm writing some Scala code which uses the  API. I would like to iterate over the rows contained in the java.util.Iterator that I get from the Sheet class. I would like to use the iterator in a for each style loop, so I have been trying to convert it to a native Scala collection but will no luck.  I have looked at the Scala wrapper classes/traits, but I can not see how to use them correctly. How do I iterate over a Java collection in Scala without using the verbose while(hasNext()) getNext() style of loop?  Here's the code I wrote based on the correct answer:  class IteratorWrapper[A](iter:java.util.Iterator[A]) {     def foreach(f: A =&gt; Unit): Unit = {         while(iter.hasNext){           f(iter.next)         }     } }  object SpreadsheetParser extends Application {     implicit def iteratorToWrapper[T](iter:java.util.Iterator[T]):IteratorWrapper[T] = new IteratorWrapper[T](iter)      override def main(args:Array[String]):Unit =     {         val ios = new FileInputStream("assets/data.xls")         val workbook = new HSSFWorkbook(ios)         var sheet = workbook.getSheetAt(0)         var rows = sheet.rowIterator()          for (val row &lt;- rows){             println(row)         }     } } In bash, calling foo would display any output from that command on the stdout.  Calling foo &gt; output would redirect any output from that command to the file specified (in this case 'output').  Is there a way to redirect output to a file and have it display on stdout? I can't figure out how to turn on the Bluetooth on my Nikon D5600. I have updated the firmware to the latest 1.01 and still the same problem.   Bluetooth is dimmed out on the camera and will not turn on. I get an error message saying, "This option is not available at current settings or in the camera's current state".  I have tried everything I can think of and no go. I can't find help for this problem anywhere on the internet and still no reply from Nikon.  How do I turn on my camera's Bluetooth? Uncountable $\sigma$-algebra I'm stuck on the following problem (Source: Real Analysis for Graduate Students; Exercise 2.6; ):     Suppose $\mathcal A$ is a $\sigma$-algebra with the property that whenever $A \in \mathcal A$, there exists $B, C \in \mathcal A$ with $B \cap C = \emptyset$, $B \cup C = A$, and neither $B$ nor $C$ is empty. Prove that $\mathcal A$ is uncountable.   I think there is the added assumption that this is only true for $A \in \mathcal A$ having at least two elements, so it doesn't hold for singletons and the emptyset?  I tried to show this by way of contradiction and say that $\mathcal A = \{A_k\}$ is countable, but I didn't see how this could get me to a contradiction.  The other approach I tried was to look at $X = B_1 \cup C_1$ where $B_1 \cap C_1 = \emptyset$, then look at $B_1 = B_2 \cup C_2$ where $B_2 \cap C_2 = \emptyset$ and so on. If I look at the $C_k$'s they are pairwise disjoint and I either have a finite number of them or an infinite number of them in which case I've created a countable sequence of pairwise disjoint nonempty elements of $\mathcal A$. This path looked promising, but I couldn't see what to do next. Any ideas?  As a secondary question: I think this result is supposed to be used to show that if $\mathcal A$ is a $\sigma$-algebra with infinitely many elements, then it's uncountable, but I wasn't able to show that the property mentioned above (the one I'm trying to show) was satisfied in this case. Geoserver ecw plugin problem I am trying to publish some ecw files with geoserver 2.7.2 on ubuntu 15.04 x64. I downloaded gdal plugin, gdal_data and native libraries for image-io 1.1.11 and set environment variables; GDAL_DATA, LD_LIBRARY_PATH.  I can see new store types when adding new one (ECW, EHdr, JP2ECW etc.). But when I try to save an ECW store with a valid ecw file which I tested with ArcMap, geoserver crashes with this error:    terminate called after throwing an instance of 'std::length_error'   what():  basic_string::_S_create Aborted (core dumped)  Do you have any idea about this problem? Let $A= a(i,j)$ and $B= b(i,j)$ be ($n\times n$) matrices that are positive definite such that $a(i,j) &lt; b(i,j)$ .Let $C= c(i,j)= a(i,j) - b(i,j)$, then $C$ is also positive definite. Why or why not?  what i know is $x^T(C)x= x^T (A-B) x = x^T(A)x - x^T(B)x$. Now both terms on right-hand side are greater than $0$ as $A$ and $B$ are positive definite. Also  $a(i,j) &lt; b(i,j)$. But in such case the sign of $x^T(C)x$ being positive or negative will also depend on the value of elements of vector $x$. So, we can't assure that $x^T(C)x &lt; 0$ always or that $C$ is not positive definite.  Am i right about this? How to redirect output of a running program to /dev/null I know that in order to suppress the output of a program I can redirect it to /dev/null, for example to hide all error and warning messages from chromium I can start the program like this  chromium-browser 2&gt; /dev/null &amp;   However, if I happen to forget about the error messages and type  chromium-browser &amp;   (which is quite annoying when they appear in the middle of a command) I don't know what to do except for stopping the application and starting it again properly.  Can I somehow redirect error output without restarting the application? If an polynomial has a complex root, is it necessary that the conjugate of that root is also a root of the polynomial? I am not sure about this. Please comment on this. I have a common scenario in app design, where I need to store an ordered list, and make the ordering easily accessible and adjustable via an application UI.    The ordering operations are simple and operate on only one item at a time - move to top, move to bottom, move up one position, or down one position.  These positioning operations may be interspersed in with typical add / edit / delete list operations.  For discussion, this is a single-user app and db store.  Because the objects can be highly complex, I'd like to avoid caching the entire list client-side, and tracking newly created objects in memory until a big save operation occurs.    I am using MS-SQL almost exclusively on these projects, and I'm wondering if there are db features, SQL features, or design patterns I should be using to better support the management of ordered lists.    My current approach is to use a DECIMAL column to store the list positions, which become fractional during the item move process.  Then I sort the list and re-generate integer positions to normalize list.  Following this operation, it's ready for another item move.   In an example implementation, I create a column named Seq for position tracking.  Once decimal place is enough for the .5 storage.   [Seq] [decimal](10, 1) NOT NULL   When an item is re-positioned in the app UI,    I UPDATE that record with new Seq value I retrieve the full table, sorted ascending by Seq and regenerate all Seq values in the table from a 1-based integer series   The new Seq value is easily calculated-    Move to top = 0 Move to bottom = MAX(Seq) + 1 Move up = subtract 1.5 from the current Seq value Move down = add 1.5 to the current Seq value   As lists get longer, updates get slower, since I'm doing N UPDATE statements, where N is the number of rows in the table, so it seems only suitable for small tables.    Is there some kind of in-built capability for managing an ordered list in SQL or MS-SQL? Is there a means to update multiple rows in one call?    A far more performant approach would be to allow more decimal places, and then position at the median of the two adjacent items, with no re-sequencing on the list.     Move to top = Min(Seq) - 1 Move to bottom = MAX(Seq) + 1 Move up = median of the 2 previous item Seq values Move down = median of the 2 following item Seq values   This approach only requires one SELECT (containing 2 rows max) and one UPDATE.    However with enough re-positions I imagine the field would run out of decimal places. For example, if I start with items at positions 10 and 11, and keep moving items down the list from position 9, they'd be given sequences of 10.5, then 10.25, then 10.125.  After 10 moves, the positions get lengthy... 10.0009765625.    UPDATE #1 - IMPROVED RE-SEQUENCING OF THE LIST  Regarding re-sequencing, I'm more caught up on row_number(), OVER, and WITH capabilities in MS-SQL.  It's nice to find that there's a much smoother way to re-sequence the list in a single UPDATE operation;  with OrderedItems as  (     select         ItemID,         Seq,         row_number() over (order by Seq asc) NewSeq     from          Items ) update OrderedItems set Seq = NewSeq ERROR 000212: Cannot create XY event source Failed to execute (MakeXYEventLayer)? I have a csv file that is 133mb in size and has over 1.3 million lines of data.  Each line of data has its own lat/long and I was wondering what would be the best way to display those points based off the lat/longs in ArcGIS Desktop 10 and ultimately turn it into a point shapefile?  So far I have tried the "Make XY Event Layer" tool but that keeps failing...  ERROR 000212: Cannot create XY event source Failed to execute (MakeXYEventLayer).  The csv file is properly formatted and the lat/long fields are numeric so I have no idea why it keeps crashing.  Here is what the first 2 lines of my CSV look like, the first line is what should be the header:  "LAT","LONG","CUSTOMER_MASTER_ID","STORE_NBR","TRANSACTION_DT","SKU_DIVISION_ID","SKU_DEPARTMENT_ID","SKU_CLASS_ID","SKU_CATEGORY_ID","SKU_NBR","SALES_AMT" "32.363544","-110.969778","2000000792627","2940","8/11/2010","2060","3920","5120","84021","5127866","13.99"   Any ideas? How do I clear Bash's cache of paths to executables? How to apply custom headers/footers on pages with new chapters? I'm writing my final report in LaTeX for my bachelor's degree. I'm aiming at having a document similar to the .doc template used normally.   I want to have my customs headers and footers applied on pages when I'm starting a new chapter.  I'm using documentclass report with fancyhdr and lastpage packages.  My headers are defined like this:  \lhead{\myTitle} \rhead{\today} \cfoot{\thepage\ of \pageref{LastPage}}   My chapters are created using standard \chapter{title} macro.  On pages with new chapters, the only headers/footers I see is the standard page number at the bottom.  What should I do?  EDIT: I've finally gone with Peter Breitfeld's solution. I'Ve gone a step further and created my own chapter command:  \newcommand{\myChapter}[1]{     \chapter{#1}     \thispagestyle{fancy} }   Thanks for the help! I have a sprite that moves from waypoint to waypoint. It turns to face its velocity vector, but not instantly (there's a rotation speed).  The problem I'm having is, from one direction to another, the sprite will often turn in wild, unnecessary ways instead of appearing like you might expect a car to appear (turn such that the minimum delta in angle occurs).  Right now I'm using the following formula to calculate the rotation float for the current velocity:  MathHelper.PiOver2 + -Math.Atan2(anotherVector.Y - vector.Y, -(anotherVector.X - vector.X));   And then I lerp the current rotation by the new rotation by the rotation speed (10f):  rotation = MathHelper.Lerp(rotation, targetRotation, 10f * (float)gameTime.ElapsedGameTime.TotalSeconds);   But unfortunately, it's causing the sprite to spin in wild directions before reaching the correct angle. Any suggestions? How do I install a Fortran 77 compiler? I have just installed 12.04 LTS on my laptop and I'm kinda new in this. I am required to write some program in Fortran 77 and I need a Fortran 77 compiler. I have tried installing g77 as described in the Ubuntu website but was unable to do so. I have typed in the following in terminal:  sudo apt-get install g77   and get the following:  Reading package lists... Done Building dependency tree        Reading state information... Done Package g77 is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source  E: Package 'g77' has no installation candidate   May I know what is the problem? I have tried searching g77 in the software center but apparently it is not there. Does this mean it is not available for 12.04?  I'm currently using an Asus K43S laptop with Intel Core i5-2450M processor and my Ubuntu is installed alongside Windows. How to extract the last inserted row in SQL Server? When an insert statement is executed one or more rows is inserted into the table, is there any way to extract the last inserted row in SQL Server? For the Pell's equation where $d=2$: $$x^2-2y^2=1$$ What are all the integer solutions to the equation. Apparantly there are infinitely many solutions, but how would I represent them in an expression? Kill the [bugs] tag? 7 segment binary to hex What is the difference between: Rooting, Jailbreak, ROM, Mod, etc.? What is the difference between:   Unlocking the bootloader (prerequisite for doing many, though not all, other things below) Rooting Jailbreaking ROM NAND and Nandroid Operating System Mod (e.g. CyanogenMod) Recovery (ClockworkMod, Amon Ra) Custom Kernel (e.g. LeshaK's kernel) Firmware Driver Over The Air (OTA) update Fastboot SIM unlocking Flashing SPL (Second Program Loader)   (any other often-confused terms that I've missed?)