Is there a way to make PDFs assume different colours when viewed on screen as opposed to when printed on paper?  As an example, I am using the titlesec package to make section labels a fancy dark blue. However, when I go on to print it, the labels look practically black. I'd like to fix this problem without having to produce a second version of my document by automatically replacing dark colors with brighter ones during printing.  Update regarding Ulrike's comment: I need this to work not just with Adobe Acrobat but other viewers as well. The suggested solution therefore does not work for me.
I am interested in displaying some things (e.g.: title page) in full color on screen, while having the same object/page display in a black and white friendly form when printed.  According to , there is built-in functionality in the PDF specification for Screen-Only objects and Screen-And-Print objects.  There may also be a way to add a layer on top of the B&amp;W page that only displays the full color page on screen via the PDF 1.5 Optional Content Groups feature.  Similarly,  demonstrates the selective printing of text via ocg-p.  But it is not clear how I can use this package in the way that I need to.  My scenario is compounded by the fact that my color page text is white on a dark background.  MWE:  This code presents the way I am currently switching back and forth between color and b&amp;w.  I change the printincolor bool variable to make the change.  \documentclass[11pt]{article}  \usepackage[demo]{graphicx} \usepackage{etoolbox}  \providebool{printincolor} % Will set color title page and section headings \setbool{printincolor}{false}  % Setup color if needed \ifbool{printincolor}{% \usepackage[pagecolor=none]{pagecolor}% \definecolor{MyBlue}{HTML}{1b3667}% \usepackage{afterpage}}{}  \begin{document}  % Begin Title Page {  \thispagestyle{empty}   \ifbool{printincolor}{%   \pagecolor{MyBlue}%   \afterpage{\nopagecolor}}{}   \begin{center}   {\ifbool{printincolor}{\color{white}\sffamily}{\sffamily}%  Set text color white or leave [default] black   \ifbool{printincolor}{\includegraphics[width=1.5in]{logo-gold}}{\includegraphics{logo-blue}}% put logo gold or blue   \\ \vskip 1in   \begin{huge}         \textbf{Title}         \vskip 0.1ex\rule{0.5\textwidth}{0.8pt}\vskip 1ex         Subtitle         \\         \end{huge}   \vfill\vfill   \begin{large}    Authors:\\   John Doe and Jane Doe\\   \end{large}   }   \end{center} }  \end{document}   How can I layer (or otherwise display) two versions of the title page in a way that color displays on screen, but black and white is printed?
Reading an Excel file in PHP I'm trying to read an Excel file (Office 2003). There is an Excel file that needs to be uploaded and its contents parsed.  Via Google, I can only find answers to these related (and insufficient topics): generating Excel files, reading Excel XML files, reading Excel CSV files, or incomplete abandoned projects. I own Office 2003 so if I need any files from there, they are available. It's installed on my box but isn't and can't be installed on my shared host.  Edit: so far all answers point to  and/or  about how to use it. If $A=\left( \begin{array}{ccc} 0 &amp; 1 &amp; 0 \\ 0 &amp; 0 &amp; 1 \\ 1 &amp; 0 &amp; 0 \end{array} \right)$, find the rank of $A+A^2+A^3$  We have $\rho(A+A^2+A^3)\leq\rho(A)+\rho(A^2)+\rho(A^3) $ where $\rho(A)$ means rank of A.  Here $\rho(A)=3.$ Also $\rho(A^2)=3$ and $\rho(A^3)=3$  as $\det A\neq 0$ and $\det(A^2)=\det(A)\det(A)\neq 0$ and so on.   But how to get the desired result. File issues after importing Drupal site I recently tried to move my Drupal site to a new server using this page: . But now the style doesn't seem be loaded and more importantly I get this error on every page in the site (even on the frontpage):  Warning: file_put_contents(temporary://filef76T9k): failed to open stream: &quot;DrupalTemporaryStreamWrapper::stream_open&quot; call failed in file_unmanaged_save_data() (line 1900 of /Library/Server/Web/Data/Sites/Default/drupal/includes/file.inc). The file could not be created.  Any ideas what this could be about? How does RewriteBase work in .htaccess What does 'per unit frequency' refer to? We were discussing Kirchoff's theorem on blackbody radiation in class today and the equation was: $$e_{f}= J(f,T)$$  $e_f$ was defined as power per unit area per unit frequency. What does per unit frequency refer to here? I know what per unit time means but don't understand 'per unit frequency'. How do I create a PDO parameterized query with a LIKE statement? Old Sci-Fi book with skin crystalizing disease and characters with psi powers File1:  .tid.setnr := 1123  .tid.setnr := 3345  .tid.setnr := 5431 .tid.setnr := 89323   File2:  .tid.info := 12 .tid.info := 3 .tid.info := 44 .tid.info := 60   Output file:  .tid.info := 12 .tid.setnr := 1123 .tid.info := 3 .tid.setnr := 3345 .tid.info := 44 .tid.setnr := 5431 .tid.info := 60 .tid.setnr := 89323 Property of Entire Functions I want to update ubuntu 11.04 throught apt-get. So I added the following lines in apt.conf  export http_proxy=http://username:password@proxyserver.net:port/ export ftp_proxy=http://username:password@proxyserver.netport/  export http_proxy=http://deepak:Deepak@123@12.1.1.1:3128   My question is: how do I insert special characters to a username or password?  For instance: my password for proxy is Deepak@123 and it is getting an error. Let $G(r, n)$ be the Grassmannian of the set of all $r$-planes in a $n$-dim vector space. How to show that the cohomology of a Grassmannian has a basis consisting of the equivalent classes represented by Schubert cycles? I am confused since I don't know how to compute the cohomology of a variety (how to construct the co-chain complex). I am really appreciate if you can compute the cohomology of, for example, $G(2,4)$ and show that it has a basis consisting of the equivalent classes represented by Schubert cycles. What is Chromatic Aberration? Is it a physical part of the lens, or just an optical illusion? "find: missing argument to `-exec'" when using "-exec rm -f {}\" Prove $-(-a)=a$ using only ordered field axioms I need to prove for all real numbers $a$, $-(-a) = a$ using only the following properties:     I tried by starting with P12 written using symbolic logic:  $\begin{align} \forall a,b \in P \to &amp; a \cdot b \in P \Leftrightarrow True \\ \forall a \in P \land \forall b \in P \to &amp; a \cdot b \in P \Leftrightarrow True \\ \lnot \left[ \left( \forall a \in P \right) \land \left( \forall b \in P \right) \right] \lor &amp; a \cdot b \in P \Leftrightarrow True \\ \exists a \notin P \lor \exists b \notin P \lor &amp; a \cdot b \in P \Leftrightarrow True \\ \end{align} \\ $  and played with evaluating it with $b = -1$, $-a$ and so on. But, felt this wasn't really a solution because the last symbolic logic statement above is ambiguous.  Not to mention--other than P12--I haven't used any of the axioms listed above whatsoever. ( And I've not bothered to prove any of the theorems of symbolic logic I have used. )  Can anyone give me a start on this problem?  Many thanks in advance.  Edit  Thank you, everyone! .  Best regards! Reset lightning:input textbox Field Value to Null I am trying to create a button which will update a field value to null (RESET it). However, it's not working and not even giving any error. So when I click on the button, nothing happens.  lc.cmp:  &lt;aura:attribute name="myObj" type="Account" default="{'SObject':'Account'}"/&gt; &lt;lightning:input type="text" name="accountPhn" label="Enter Account Phone" value="{!v.myObj.Name}"/&gt; &lt;lightning:button label="Reset" onclick="{!c.resetMe}"/&gt;   lc.js:  resetMe : function(component, event, helper) {         //alert("Called");         component.set("v.accountPhn","");     }   Appreciate help around this. Java inner class and static nested class What is the main difference between an inner class and a static nested class in Java? Does design / implementation play a role in choosing one of these? When looking at my objects in 3d view I'm seeing a gray cone that seems to be hiding other objects.   Can anyone help me turn this off and explain what it is please.  Screenshots attached. Do not hide VLQ flag option from users who already flagged and may wish to retract System hides an option to flag Very Low Quality in few cases, namely when post is:        Because of that users who already flagged it when none of above conditions applied miss an option to .  Suggest1 to show this flag option to such users so that they could retract a flag.    1 Frankly I won't mind if this gets  because I doubt that it is important. This is posted mainly to document how system behaves and to provide reference for those who may wonder why they can't retract flag in some cases. I have been using the default Ubuntu 11.10 with Unity for some time now and decided to start customizing it.  I have already been able to make some changes with the gnome-tweak-tool. However, there are many themes that I get from gnome-look.org that don't appear in the gnome-tweak-tool even after putting them in the /usr/share/themes folder.  Any idea why this is happening? Thanks. Position of the adverb "substantially"