13.04 wont start, "cant identify screen, graphics card etc..." error
My computer boots to a black screen, what options do I have to fix it?
Display date/time in user's locale format and time offset I want the server to always serve dates in UTC in the HTML, and have JavaScript on the client site convert it to the user's local timezone.  Bonus if I can output in the user's locale date format. If $2^n - 1$ is prime from some integer $n$, prove that n must also be prime. Capturing emoticons using regular expression in python Unbounded continuous function on non-compact metric space Suppose $(S,d)$ is a non-compact metric space. Is it possible to construct an unbounded continuous function from $S$ to $\mathbb{R}$? If it is possible, please show the construction method :)  Here's my attempt to solve this problem: Because $S$ is not compact, we can find a neighborhood assignment function $N(x)$ so that a finite cover is not possible. Then each time we can find an uncovered point from the union of neighborhoods before, and change the function by $f(x):=max\{f(x),\text{a function which equals to the indice of this point at that point and gradually vanishes at further points from the selected point}\}$. However I'm concerned that while this function is unbounded, there may be some invalid points for this function (goes to infinity)...  EDIT: As I found out there is a duplicate question, however the elementary solution is not presented in that question, so I still wish to know about this problem. :) Look and you shall find (a correlation) I would like someone to explain me how the sense of a sentence changes with using "for me" or "to me":  Some examples:     1a.  She is a good friend to me.   1b.  She is a good friend for me.        2a.  How special you are to me.   2b.  How special you are for me.        3a.  It's an interesting topic to me.   3b.  It's an interesting topic for me. I am looking for shapefiles or a list of suburb names for Melbourne and Canberra. I have ABS shapefiles, but I need to filter that to end up with only metropolitan suburbs.  My shapefile has codes in it for  - I just need to know which suburbs belong to the metros. Can I create a shortcut to open a specific application on OS X? I want to create a keyboard shortcut to i.e. open Firefox while I am working in another application. I know I can use ⌘ CMD+T when I am in Firefox to open a new tab.   I haven't found a way to create that kind of shortcuts in System Preferences.  Any ideas? AMPscript Error with XML I have a Partner sending some data to a Triggered Email/Data Extension which includes a column for XML data.   The trigger is erroring and not allowing the data to get to the Data Extension.   Below is what they are sending over. Is the formatting of the XML incorrect?  XML data that I've used in the past in Data Extensions starts with....   &lt;?xml version="1.0" encoding="UTF-8" standalone="yes"?&gt;   This version of XML starts with... {"XML":  Could that be it?  {"To": {"SubscriberKey": "test@acme.com", "ContactAttributes": {"SubscriberAttributes": **{"XML":** "&lt;root&gt;&lt;ITEM&gt;&lt;ITEM_PRODUCT_NAME&gt;dark chocolate nuts &amp; sea salt&lt;/ITEM_PRODUCT_NAME&gt;&lt;ITEM_PRODUCT_SKU&gt;15127&lt;/ITEM_PRODUCT_SKU&gt;&lt;ITEM_PRODUCT_URL&gt;https://www.test.com/15127.html&lt;/ITEM_PRODUCT_URL&gt;&lt;ITEM_PRODUCT_IMG_URL&gt;https://www.test.com/images/nuts.png&lt;/ITEM_PRODUCT_IMG_URL&gt;&lt;ITEM_QTY&gt;1&lt;/ITEM_QTY&gt;&lt;ITEM_SUBSCRIPTION_PRICE&gt;12.59&lt;/ITEM_SUBSCRIPTION_PRICE&gt;&lt;ITEM_TOTAL&gt;12.59&lt;/ITEM_TOTAL&gt;&lt;/ITEM&gt;&lt;ITEM&gt;&lt;ITEM_PRODUCT_NAME&gt;crunchy peanut butter&lt;/ITEM_PRODUCT_NAME&gt;&lt;ITEM_PRODUCT_SKU&gt;41800&lt;/ITEM_PRODUCT_SKU&gt;&lt;ITEM_PRODUCT_URL&gt;https://www.test.com/images/butter.png&lt;/ITEM_PRODUCT_IMG_URL&gt;&lt;ITEM_QTY&gt;1&lt;/ITEM_QTY&gt;&lt;ITEM_SUBSCRIPTION_PRICE&gt;11.37&lt;/ITEM_SUBSCRIPTION_PRICE&gt;&lt;ITEM_TOTAL&gt;9.55&lt;/ITEM_TOTAL&gt;&lt;/ITEM&gt;&lt;ITEM&gt;&lt;ITEM_PRODUCT_NAME&gt;pear cinnamon &amp; pecan&lt;/ITEM_PRODUCT_NAME&gt;&lt;ITEM_PRODUCT_SKU&gt;17227&lt;/ITEM_PRODUCT_SKU&gt;&lt;ITEM_PRODUCT_URL&gt;https://www.test.com&lt;/ITEM_PRODUCT_URL&gt;&lt;ITEM_PRODUCT_IMG_URL&gt;https://www.test.com/images/apples.png&lt;/ITEM_PRODUCT_IMG_URL&gt;&lt;ITEM_QTY&gt;1&lt;/ITEM_QTY&gt;&lt;ITEM_SUBSCRIPTION_PRICE&gt;12.59&lt;/ITEM_SUBSCRIPTION_PRICE&gt;&lt;ITEM_TOTAL&gt;12.59&lt;/ITEM_TOTAL&gt;&lt;/ITEM&gt;&lt;/root&gt;", "SHIPPING_LNAME": "Tester", "FIRST_NAME": "Test", "LAST_NAME": "Tester", "ORDER_TOTAL_SAVINGS": -5.97, "MERCHANT_ORDER_ID": "1810002352", "SHIPPING_ADDRESS_STATE": "NY", "ORDER_PLACE_DATE_LONG": "Fri 11 January 2019", "SHIPPING_ADDRESS_ZIP": "10004", "ORDER_SHIPPING": 0.00, "CARD_TYPE": "Visa", "ORDER_SUBTOTAL": 47.32, "ORDER_PLACE_DATE_SHORT": "01/11/2019", "SHIPPING_FNAME": "Test", "SHIPPING_ADDRESS_TOWN": "new york", "ORDER_TOTAL": 47.32, "CARD_EXPIRE": "12/2027", "CARD_HOLDER": "Test Tester", "SHIPPING_ADDRESS_1": "75 broad st", "SHIPPING_ADDRESS_2": "fl 23"}}, "Address": "acme@test.com"}}   AMPSCRIPT IN EMAIL Calling the XML....  %%[   var @LOOPINGAPPENDIX  set @LOOPINGAPPENDIX = AttributeValue("LOOPINGAPPENDIX")  set @productRows = BuildRowSetFromXML(@LOOPINGAPPENDIX, "/root/ITEM", 0)  ]%%   %%[   for @j = 1 to RowCount(@productRows) do       set @productXML = Concat("", Field(Row(@productRows, @j), "XML"), "")      set @ITEMPRODUCTNAME = Trim(Field(Row(BuildRowSetFromXML(@LOOPINGAPPENDIX, "/root/ITEM/ITEM_PRODUCT_NAME", 0), 1), "Value"))      set @ITEMPRODUCTSKU = Trim(Field(Row(BuildRowSetFromXML(@LOOPINGAPPENDIX, "/root/ITEM/ITEM_PRODUCT_SKU", 0), 1), "Value"))      set @ITEMPRODUCTURL = Trim(Field(Row(BuildRowSetFromXML(@LOOPINGAPPENDIX, "/root/ITEM/ITEM_PRODUCT_URL", 0), 1), "Value"))      set @ITEMPRODUCTIMGURL = Trim(Field(Row(BuildRowSetFromXML(@LOOPINGAPPENDIX, "/root/ITEM/ITEM_PRODUCT_IMG_URL", 0), 1), "Value"))      set @ITEMQTY = Trim(Field(Row(BuildRowSetFromXML(@LOOPINGAPPENDIX, "/root/ITEM/ITEM_QTY", 0), 1), "Value"))      set @ITEMSUBSCRIPTIONPRICE = Trim(Field(Row(BuildRowSetFromXML(@LOOPINGAPPENDIX, "/root/ITEM/ITEM_SUBSCRIPTION_PRICE", 0), 1), "Value"))      set @ITEMTOTAL = Trim(Field(Row(BuildRowSetFromXML(@LOOPINGAPPENDIX, "/root/ITEM/ITEM_TOTAL", 0), 1), "Value"))      set @rowColor = Iif(Mod(@j,2) == 0, "#efefef", "#ffffff")   ]%%   %%[endif]%%   %%[next @j]%% "It's cold today" -- what term do linguists use to call "it" when it's used as the subject of a sentence, but has no real antecedent? Show that $a^2 \bmod b = (a \bmod b)^2 \bmod b$ Show that  $$a^2 \mathrm{\ mod \ } b = (a \mathrm{\ mod \ } b)^2 \mathrm{\ mod\ } b$$ for $ a, b \in \mathbb{Z}^+ $.  this was derived from an Informatics olympiad question. Can there be true conclusions without assumptions? I was thinking of the sentence  "I think therefore I am",  which I had for a long time considered indisputable because it's self-evident.   Then I considered the hypothetical situation where my thoughts are illogical – and of course I can't be aware that they are – and so to a logical outsider I am not saying something that is actually indisputable and self-evident, but in fact may be total nonsense. Perhaps there is a hypothetical evil demon altering my ability to reason. However convincing it seems to me that I MUST exist since, in whatever since "I" or "exist" is, there is the ability to question whether I do, the conclusion can't actually be trusted without doubt since I cannot know if I am in fact reasoning logically.  Even what I consider to be trivial tautologies require this assumption of sanity, and therefore there is no true conclusion without assumption – an assumption about the nature of my own reasoning. The only absolute truth I have is unspeakable subjective experience, and any articulation (and I realize the apparent circular reasoning I've cornered myself into here...) is necessarily uncertain.  I realize that perhaps this doesn't even make sense, but was just curious if anyone had entertained this line of thought and come to some satisfying resolution. This question is pretty simple: I'd like to have the possibility to get the exact size of a picture in LaTeX with, for example, the macro \the.  In fact, I've founded the way \settoheight{} and so on, but it didn't work at all. What I've got doesn't match with what I can see in the image properties (I suppose that's the name in English). The result: 8pt versus 1300 pixels. It's may be a mis-use...  Edit: In the end, my aim was to find a way to fit the picture in LaTeX. If width and height were both less than the dimensions of the body, then it should just be centred. It look like this :     Require:   \usepackage{graphicx} \usepackage{xifthen} \usepackage{calc}   Code (pretty ugly, I agree):   % Centrering+fitting for image, with captation and label (not auto) \newlength\imageheight \newlength\imagewidth \newcommand{\pic}[3]{% \settoheight\imageheight{\includegraphics{pictures/#1.png}}% \settowidth\imagewidth{\includegraphics{pictures/#1.png}}% \ifthenelse{\lengthtest{\imagewidth &gt; \textwidth}}{\ifthenelse{\lengthtest{\imageheight &gt; \imagewidth}}{\par\vspace{0.95em}% \begin{figure}     \centering\includegraphics[height=0.85\textheight]{pictures/#1.png}     \caption{#2}     \label{#3} \end{figure}% \par\vspace{0.95em}}{\par\vspace{0.95em}% \begin{figure}     \centering\includegraphics[width=0.95\textwidth]{pictures/#1.png}     \caption{#2}     \label{#3} \end{figure}% \par\vspace{0.95em}}}{\ifthenelse{\lengthtest{\imageheight &gt; \textheight}}{\par\vspace{0.95em}% \begin{figure}     \centering\includegraphics[height=0.85\textheight]{pictures/#1.png}     \caption{#2}     \label{#3} \end{figure}% \par\vspace{0.95em}}{\par\vspace{0.95em}% \begin{figure}     \centering\includegraphics{pictures/#1.png}     \caption{#2}     \label{#3} \end{figure}% \par\vspace{0.95em}}}} %   To use it : put your png files in a "pictures" directory, then, just simply call the picture like this : \pic{name_whitout_extension}{Captation_if_needed}{Label_if_needed}.    Edit 2 :   Thanks to Martin Scharrer's easyfig package, I've got a more or less 1,6 times faster solution to put my pictures, centred, with the perfect size.  CTAN:   VC:   Version v1.2 – 2012/05/15    This could be useful for some others, I hope. How do electromagnetic waves wave? Electromagnetic waves have a physical crest and trough as observed in microwaves and radio waves. I understand that is electromagnetic field vectors that wave, not the photon. But how do they wave? What does causes them to change direction? Meta duplicates don't require an answer. Don't suggest there is one when that's not true This request was sparked . The vote to close as a duplicate on meta, in contrast to the main site, does not require for the duplicate to have an answer. Yet, the closure message still says:     This question has been asked before and already has an answer.    ...even when this is not the case. Perhaps we should either only show this particular sentence if there is indeed an answer, or remove this altogether for meta.   Note: I fear this might be a duplicate request, but I was unable to find one. (Not even one without an answer :) ) Trace of a commutator is zero - but what about the commutator of $x$ and $p$? Operators can be cyclically interchanged inside a trace: $${\rm Tr} (AB)~=~{\rm Tr} (BA).$$ This means the trace of a commutator of any two operators is zero: $${\rm Tr} ([A,B])~=~0.$$ But what about the commutator of the position and momentum operators for a quantum particle? On the one hand: $${\rm Tr}([x,p])~=~0,$$ while on the other hand: $$[x,p]~=~i\hbar.$$ How does this work out? node.js conflicts: /sbin/node vs /usr/bin/node I have two Ubuntu 12.10 machines: machine A is a VMWare VM and machine B is and old Acer laptop. On both machines, I installed node using apt-get. However machine A installs the main binary as /usr/bin/node and machine B as /usr/bin/nodejs. Here are some behaviors I observed:   Both machine returns /usr/bin/node in response to the which node command. However, there is no such file on machine B. Issuing the command node works for machine A, not B. On B, I have to use nodejs instead. On B, there is a binary called /sbin/node, A does not have it.   These behaviors causes inconsistency problem when developing on both machines. For now, I worked around by renaming the binaries on B as such:  sudo mv /sbin/node /sbin/node-sbin sudo ln -s /usr/bin/nodejs /usr/bin/node   Is there a way to really fix this, so that node will be installed as /usr/bin/node instead of /usr/bin/nodejs? Do I need to upgrade RAM from 4GB to 8GB for Android development? I'm an android developer and have laptop with 4GB RAM. When I compile my project the RAM is used at 100%.    If I add more RAM will it solve the problem? I needed some simple string encryption, so I wrote the following code (with a great deal of "inspiration" from ):      // create and initialize a crypto algorithm     private static SymmetricAlgorithm getAlgorithm(string password) {         SymmetricAlgorithm algorithm = Rijndael.Create();         Rfc2898DeriveBytes rdb = new Rfc2898DeriveBytes(             password, new byte[] {             0x53,0x6f,0x64,0x69,0x75,0x6d,0x20,             // salty goodness             0x43,0x68,0x6c,0x6f,0x72,0x69,0x64,0x65         }         );         algorithm.Padding = PaddingMode.ISO10126;         algorithm.Key = rdb.GetBytes(32);         algorithm.IV = rdb.GetBytes(16);         return algorithm;     }      /*       * encryptString      * provides simple encryption of a string, with a given password      */     public static string encryptString(string clearText, string password) {         SymmetricAlgorithm algorithm = getAlgorithm(password);         byte[] clearBytes = System.Text.Encoding.Unicode.GetBytes(clearText);         MemoryStream ms = new MemoryStream();         CryptoStream cs = new CryptoStream(ms, algorithm.CreateEncryptor(), CryptoStreamMode.Write);         cs.Write(clearBytes, 0, clearBytes.Length);         cs.Close();         return Convert.ToBase64String(ms.ToArray());     }      /*      * decryptString      * provides simple decryption of a string, with a given password      */     public static string decryptString(string cipherText, string password) {         SymmetricAlgorithm algorithm = getAlgorithm(password);         byte[] cipherBytes = Convert.FromBase64String(cipherText);         MemoryStream ms = new MemoryStream();         CryptoStream cs = new CryptoStream(ms, algorithm.CreateDecryptor(), CryptoStreamMode.Write);         cs.Write(cipherBytes, 0, cipherBytes.Length);         cs.Close();                     return System.Text.Encoding.Unicode.GetString(ms.ToArray());     }   The code appears to work fine, except that when decrypting data with an incorrect key, I get a CryptographicException - "Padding is invalid and cannot be removed" - on the cs.Close() line in decryptString.   example code:      string password1 = "password";     string password2 = "letmein";     string startClearText = "The quick brown fox jumps over the lazy dog";     string cipherText = encryptString(startClearText, password1);     string endClearText = decryptString(cipherText, password2);     // exception thrown   My question is, is this to be expected? I would have thought that decrypting with the wrong password would just result in nonsense output, rather than an exception. Command line option to check which filesystem I am using? Is there a command that will show which file system (ext3, ext4, FAT32, ...) the various partitions and disks are using?   Similar to how sudo fdisk -l lists information about disks and partitions?