I'm new to this site and I'm searching for the help. I'm trying to plot an adsorption isotherm described with specific equation. I used pgfplots package with following commands:  \documentclass{article} \usepackage{pgfplots} \begin{document} \begin{tikzpicture}[baseline] \begin{axis}[ ymin=0, ymax=100, xmin=0, xmax=105, ]% \addplot[violet,domain=0:100,samples=999]{((38.25708798*23.0303696*(x/41.77116184))/(1-(x/41.77116184)))*((1-(2.76389715+1)*((x/41.77116184)^2.76389715)+2.76389715*((x/41.77116184)^(2.76389715+1)))/(1+((23.0303696-1)*(x/41.77116184))-23.0303696*((x/41.77116184)^(2.76389715+1))))}; \end{axis} \end{tikzpicture} \end{document}   which leads to the:    The plotted isotherm has an error shape, because the plotted isotherm should be:    Am I missing something, or is it a bug of the PGFPlots package?
I am trying to plot the function 1/x^2 but the result is obviously wrong, here is how it looks like    here is the code  \begin{center}      \begin{tikzpicture}      \begin{axis}[      %xlabel=$x$,     %ylabel={$f(x) = x^2 - x +4$}   ]      \addplot[blue] {1/(x^2)};     \end{axis}     \end{tikzpicture} \end{center}   Any suggestions on how to fix this?
What's the easiest way to play a sound file (.wav) in Python? By easiest I mean both most platform independent and requiring the least dependencies. pygame is certainly an option, but it seems overkill for just sound. Why does my server show              total      used      free   shared buffers    cached     Mem: 12286456  11715372    571084        0   81912   6545228 -/+ buffers/cache:  5088232   7198224    Swap: 24571408     54528  24516880   I have no idea on calculating the memory in linux. I think it says that 5088232 is used where as 7198224 is free, meaning it is actually consuming 5GB of RAM? Solving minimization problem $L_2$ IRLS (Iteration derivation) In the article ''' Chartrand, Rick, and Wotao Yin. "Iteratively reweighted algorithms for compressive sensing." Acoustics, speech and signal processing, 2008. ICASSP 2008. IEEE international conference on. IEEE, 2008. '''  It is given that one iteration of  iterative reweighed least squares problem can be written as $\min \sum_{i=1}^N w_i u_i^2 $ subject to $\Phi u = b  $ which has a closed form solution given as   $u^{(n)} = Q_n \Phi^T (\Phi Q_n \Phi^T)^{-1} b$. where $Q_n$ is the diagonal matrix containing entries $1/(|u_i^{(n-1)}|^2 + \epsilon )^{1/2} $ And the closed form equation can be derived from the Euler Lagrange equation. Can someone please help me to get the derivation of the iteration?\ I understood till $$\min_u u^TWu+λ|| \Phi u−b||_2^2 $$  which can be written as $(\bigtriangledown=0)$ which gives $$ W u + \lambda (\Phi^T \Phi u - \Phi^T b) =0$$ How can I center a too wide table? How to run grep and show x number of lines before and after the match grep returns just the line where it matched the regex and often what I want to really see is a few (say 2) lines above and below the matched one. Is there a simple way to achieve it?  EDIT: OS: Ubuntu based Bodhi Linux.  As mentioned in comments, -C does not work in vanilla but its GNU grep in my case. Choosing whether to include PDF or PNG in PDFLaTeX Can I tell graphicx somehow which graphic format to choose when I omit the file extension in includegraphics and both a PDF and a PNG version of the same image exist? The reason is that I have some very large PDF vector graphics (in terms of file size/drawing primitives) that take a pretty long time to load each time I view the document. I would like to convert them to PNGs while working on the document and only use the PDF versions in the final document. Therefore, a global option that I can switch in the end would be great.  An additional plus would be to do the conversion to PNG on the fly during the LaTeX run if there is a PDF that has not been converted to PNG yet, if a tool for that exists. (I know how to use convert, but not how to include it automatically in LaTeX.) How many combinations of groups are there where no member of a group has been with another member before? I found this hard to word in the title, so let me give an example. I have 16 students, and I want to split them up into 4 groups of 4. However, I want to make sure that every time I have a new combination of groups, that a student has never been with any of their new groupmates before. I found info on how to separate objects into groups, but not in only unique ways as I've described above. I think I figured this out the rote way, by assigning each student a number and then finding the unique combinations, and got 3. But I'd like to know the math behind it, and how it could be applied to other configurations (20 students w/ 4 groups of 5?). Thanks for any help you can give! My keyboard has no "media" keys; can I control media without them? XeLaTeX update [20201004] and item ball in Beamer Beamer item balls go missing while compiling in XeLateX since yesterday's TeXlive update, however, the same code works with pdfLaTeX. Any solution, please. Here is my MWE: \documentclass{beamer}  \setbeamertemplate{itemize item}[ball] \setbeamertemplate{enumerate item}[ball]  \begin{document}  \begin{frame} \frametitle{A tested title} text \begin{enumerate}     \item this is an item \end{enumerate} text3 \begin{itemize}     \item this is an item \end{itemize} \end{frame} \end{document} Add the Same Modifier to Multiple Objects at Once? What is the Coandă effect? How is it defined, and what causes it? Can anybody explain to me the  well? I am finding that many definitions and explanations conflict.  I am particularly confused about the following points regarding the Coandă effect:   whether the Coandă effect is the same as normal boundary layer attachment to a surface whether the Coandă effect is only defined for convex surfaces over which a jet (of the same state as the surrounding fluid) is tangentially blown what causes the Coandă effect: the jet entraining the ambient fluid or a balance of pressure and centrifugal forces, or something else? Is this defined by the language? Is there a defined maximum? Is it different in different browsers? SQL Server compatibility with New TLS Standards On Windows 7 can one make UAC on an admin account prompt for the password, just like a limited account? I am one of the very few who likes the security of UAC and so I have the UAC set to "Always Notify" on my Admin account. But I would be even happier if the system would prompt me for a password, when notifying me.  I can get what I want by adding a second non-admin user and using that account.  But somehow it seems wasteful to have two accounts set up when I will always use the non-admin account day-to-day.  So I am wondering if there is any setting that would cause an Admin account to behave password-prompting-wise as a standard account? UIToolbar tint on iOS 4 Why does the set of all singleton sets not exist? How to generate all permutations of a list? What's the difference between the server version and the desktop version? What's the difference between the server version of Ubuntu and the desktop version? I look today on a few fresh question, and the view count was 0. Even after I refreshed the page a few time. This is definitely a bug, since the question isn't mine.  Also I don't think the all page was cached, since that the DateTime mark was change every reload.  But maybe the SQL result is cached. Microsoft.ACE.OLEDB.12.0 provider is not registered I have a Visual Studio 2008 solution with two projects (a Word-Template project and a VB.Net console application for testing).  Both projects reference a database project which opens a connection to an MS-Access 2007 database file and have references to System.Data.OleDb.  In the database project I have a function which retrieves a data table as follows   private class AdminDatabase    ' stores the connection string which is set in the New() method    dim strAdminConnection as string     public sub New()    ...    adminName = dlgopen.FileName    conAdminDB = New OleDbConnection    conAdminDB.ConnectionString = "Data Source='" + adminName + "';" + _        "Provider=Microsoft.ACE.OLEDB.12.0"     ' store the connection string in strAdminConnection    strAdminConnection = conAdminDB.ConnectionString.ToString()    My.Settings.SetUserOverride("AdminConnectionString", strAdminConnection)    ...    End Sub     ' retrieves data from the database    Public Function getDataTable(ByVal sqlStatement As String) As DataTable         Dim ds As New DataSet         Dim dt As New DataTable         Dim da As New OleDbDataAdapter         Dim localCon As New OleDbConnection           localCon.ConnectionString = strAdminConnection          Using localCon             Dim command As OleDbCommand = localCon.CreateCommand()             command.CommandText = sqlStatement             localCon.Open()             da.SelectCommand = command             da.Fill(dt)             getDataTable = dt         End Using      End Function End Class   When I call this function from my Word 2007 Template project everything works fine; no errors. But when I run it from the console application it throws the following exception     ex = {"The 'Microsoft.ACE.OLEDB.12.0'   provider is not registered on the   local machine."}   Both projects have the same reference and the console application did work when I first wrote it (a while ago) but now it has stopped work.  I must be missing something but I don't know what.  Any ideas?