I have a question with regex, I'm trying to scrape a stock price. The element surrounding it looks like this:  &lt;span class="Trsdu(0.3s) Fw(b) Fz(36px) Mb(-4px) D(ib)" data-reactid="52"&gt;17.89&lt;/span&gt;   As you see there are multiple parentheses in that element so when I try to narrow it down with the following code the parentheses cause my script not to display any results.  MatchCollection list = Regex.Matches(data, "&lt;span class=\"Trsdu(0.3s) Fw(b) Fz(36px) Mb(-4px) D(ib)\" (.+?)&lt;/span&gt;", RegexOptions.Singleline);   I Know you can ignore quotation marks using \ but is there away to ignore parentheses?
I am tired of always trying to guess, if I should escape special characters like '()[]{}|' etc. when using many implementations of regexps.  It is different with, for example, Python, sed, grep, awk, Perl, rename, Apache, find and so on. Is there any rule set which tells when I should, and when I should not, escape special characters? Does it depend on the regexp type, like PCRE, POSIX or extended regexps?
Replace Line Breaks in a String C# Call Servlet and invoke Java code from JavaScript along with parameters Steps for going from Polyakov action to low-energy effective action (SUGRA?) in String Theory A lot of string-theory questions have been asked here. This one is, hopefully, different in that this inquiry is specific and the expected answer would be more mathematical than philosophical in character.  To give some context, I'm familiar with LQG, QFT etc. I'm a beginner in CFT and string-theory. On reading papers on AdS/CFT and String Theory the following sentence often appears: "The low-energy effective action for $x$ dimensional ST of type $y$ reduces to that of supergravity (SUGRA) in $z$ dimensions with matter fields of types $a$, $b$ and $c$".  The $64,000 dollar question any noob, such as me, wants answered is what are the mathematical/technical steps or arguments which lead us from the fundamental action of string-theory (the Polyakov/Nambu-Goto action) to a low-energy effective description. Of course, I might be asking a question for which the only concise answer is: "go read GSW". Here's hoping otherwise ;) Is there a way to view your own progress towards certain badges? For example:   Tumbleweed - What value constitutes low views for a week? Fanatic  – Is there a way to view how many days in a row you currently have? Beta – Is it even possible to get this badge anymore? Can I use a EF lens with a EF-S camera? Can I put a rack on a carbon road bike? I got a carbon-framed  recently but I also want to use it for commuting to and from work and I want a place to put my lock and other stuff on the bike. Is it possible to have a rack on this kinda bike. Are these intended activities legal to do in the USA under the VWP? I'm a British citizen traveling to the USA next month with an ESTA to see my fiancee. I'm traveling there to plan our wedding, talk about a location to get married, and probably finalise a date and a booking with my fiancee (US citizen). This is the primary reason for my trip to the USA. Am I allowed to do this as a tourist? I would like to know for when the CBP officer asks me if this thing is allowed.  Am I allowed to enter the USA, on a separate trip (probably later this year), for the sole purpose of marrying my fiancee, provided I can persuade the CBP officer I intend to leave at the end of my trip? My fiancee and I are moving to the UK next year. If string is stretched just by weight, where does the gravitational potential energy goes if only half is converted to elastic potential energy? If a spring is stretched by a weight of mass m, (so the extension is $\Delta x$) then $ k = \frac W{\Delta x} = \frac {mg}{\Delta x}$. So $ k\Delta x= mg $.  When the Spring is stretched by distance $\Delta x$ (by the weight) then it looses gravitational potential enegry. ($ \Delta GPE= mg\Delta x$)  But, when we calculate the change in elastic potential energy, We get  $ U = \frac 12 k(\Delta x)^2 $. Since $ k\Delta x = mg$, $U=\frac 12 mg\Delta x$  At, equilibrium we have no kinetic energy $E_k = 0$  Doesn't that violate Energy Conservation?  Where does the rest of lost GPE goes?  Here's a illustration I need to know a word which means:     "negligence shown by a person in performing a duty, or a responsibility, or any given task."   or,      "A person who is negligent in performing their duties/responsibilities."   One possible choice is the use of word "delinquent". Is there any other word?  Please provide the usage of suggested word in a sentence also. I'm using Chrome 32 on an Android tablet (not phone) and just can't figure out how to close all open tabs in one go. Riemann integrabilty of an indicator function Consider the following function on $[0,1]$:   $$f(x)=\begin{cases}1&amp;x\in\{a_1,a_2,\dots,a_n\}\\0 &amp;\text{otherwise}\end{cases}$$   The $a_i$ are fixed and all in $[0,1]$. Determine whether $f$ is Riemintegrable or not.   By the Riemann&ndash;Lebesgue criterion $f$ is Riemann integrable. How to prove directly? Suppose I have a dataframe consisting of six time series. In this dataframe, some observations are missing, meaning at some timepoints all time series contain a NA-value. In R, one possible imputation package that can be used to impute time series data is Amelia. However, this package does not work for observations that are completely missing. Are there other ways to impute my data? For what it's worth, the amount of missing observations is less than 20% of all observations. "Effect" vs. "Affect" I've noticed that some people use effect and affect interchangeably. What are the differences between these two and when are the proper situations to use each of them? Will there be data loss if I upgrade? Select Input Texture file name as parameter/node no Wi-Fi on Ubuntu 14.04 LTS Asus notebook with MEDIATEK MT7630e I'm new to Ubuntu. I installed it today, but the first thing I encounter is that I can only connect to the Internet through wifi.  Can someone help me?   iwconfig result :  eth0      no wireless extensions.  lo        no wireless extensions.   lspci:  00:00.0 Host bridge: Intel Corporation 3rd Gen Core processor DRAM     Controller (rev 09) 00:01.0 PCI bridge: Intel Corporation Xeon E3-1200 v2/3rd Gen Core processor PCI Express Root Port (rev 09) 00:02.0 VGA compatible controller: Intel Corporation 3rd Gen Core processor Graphics Controller (rev 09) 00:14.0 USB controller: Intel Corporation 7 Series/C210 Series Chipset Family USB xHCI Host Controller (rev 04) 00:16.0 Communication controller: Intel Corporation 7 Series/C210 Series Chipset Family MEI Controller #1 (rev 04) 00:1a.0 USB controller: Intel Corporation 7 Series/C210 Series Chipset Family USB Enhanced Host Controller #2 (rev 04) 00:1b.0 Audio device: Intel Corporation 7 Series/C210 Series Chipset Family High Definition Audio Controller (rev 04) 00:1c.0 PCI bridge: Intel Corporation 7 Series/C210 Series Chipset Family PCI Express Root Port 1 (rev c4) 00:1c.1 PCI bridge: Intel Corporation 7 Series/C210 Series Chipset Family PCI Express Root Port 2 (rev c4) 00:1c.3 PCI bridge: Intel Corporation 7 Series/C210 Series Chipset Family PCI Express Root Port 4 (rev c4) 00:1d.0 USB controller: Intel Corporation 7 Series/C210 Series Chipset Family USB Enhanced Host Controller #1 (rev 04) 00:1f.0 ISA bridge: Intel Corporation HM76 Express Chipset LPC Controller (rev 04) 00:1f.2 SATA controller: Intel Corporation 7 Series Chipset Family 6-port SATA Controller [AHCI mode] (rev 04) 00:1f.3 SMBus: Intel Corporation 7 Series/C210 Series Chipset Family SMBus Controller (rev 04) 01:00.0 3D controller: NVIDIA Corporation GF117M [GeForce 610M/710M/820M / GT 620M/625M/630M/720M] (rev a1) 03:00.0 Network controller: MEDIATEK Corp. MT7630e 802.11bgn Wireless Network Adapter 04:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. Device 5289 (rev 01) 04:00.2 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 0a)   lspci -nnk | grep 0280 -A2:  03:00.0 Network controller [0280]: MEDIATEK Corp. MT7630e 802.11bgn Wireless Network Adapter [14c3:7630]     Subsystem: Foxconn International, Inc. Device [105b:e074] 04:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. Device [10ec:5289] (rev 01) In Windows 10 how can we change the name of this folder under C:\Users? I'm using Windows 10 on my personal computer (HP Pavilion Laptop) and you can see in the Screen Shot under C:\Users there are two folders.    The name of the first folder is C:\Users\SINGHA, however, the correct spelling of my last name is SINHA.  I need to change the name of this folder to C:\Users\SINHA so that it shows the correct name.     Under User Account, the spelling of my name is correct - it's only under C:\Users\ where the name is spelt incorrectly. Consequently, if I open/edit a Word or Excel document, the name of the owner being shown is the incorrect one (i.e it's shown as C:\Users\SINGHA instead of C:\Users\SINHA)   If I right-click on this folder, I won't get the Rename option; How can I change the name of this folder? Background I was ignorant as an undergraduate and didn't focus heavily in any specific area. I finally graduated with a single math/computer science degree that consisted of 5 math classes beyond multivariable calculus and a few relatively basic computer science classes (algorithm analysis, SQL database design, etc.). My only research experience is in economics. Now, I work at a research institution in economics where I primarily write Stata/MATLAB code. Question I'd like to get more mathematics under my belt over the next few years in order to either enroll in a PhD program in economics/finance or a M.S. program in finance. What are my options for getting more math experience that I can use in graduate school admissions? Options These are the options I thought of so far, but I would like to know more if possible.  Study enough courses through a system like Open CourseWare to gain enough experience to enroll in more advanced undergraduate classes part time, which my employer might pay for, and then ideally move into an M.S. program in applied math.  Return to my alma mater for a M.S. degree in math that would at least give me a basis to either move into another math graduate program with higher rankings or a lower-ranked graduate program in the fields of my choice.  Join the Air Force and hopefully take advantage of the GI bill to take more courses somewhere and gain entrance into an M.S. program in applied math.  (Sadly) Forgo advanced mathematics and find a consulting job, which although unpleasant in the field of economics (in my opinion), wouldn't be difficult to obtain given my research background in the field.   Do I have any other options? I also plan to take the GRE subject test in mathematics to prove that I have at least minimal knowledge, regardless of what course I pursue (since many graduate programs will require it). I'm trying to solve this problem from Hatcher 3.3.24.  Let $M$ be a closed connected 3-manifold, and write $H_1(M, \mathbb{Z})$ as $\mathbb{Z^r} \oplus T$ where $T$ is torsion. Show that $H_2(M, \mathbb{Z})$ is $\mathbb{Z^r}$ if $M$ is orientable or $\mathbb{Z^{r-1}} \oplus \mathbb{Z_2}$ if $M$ is not orientable. In particular $r \geq 1$ if $M$ is not orientable. Using exercise 6 construct examples showing there are no other restrictions on the homology groups of closed 3-manifolds. (In the nonorientable case consider the manifold $N$ obtained from $S^2 \times I$ by identifying $S^2 \times \{0\}$ with $S^2 \times \{1\}$ via a reflection of $S^2$.)  I think I've solved the first part, here's my proof:   First note the following theorem: If $M$ is a closed connected and orientable n-manifold then $H_n(M, \mathbb{Z}) = \mathbb{Z}$ and $Tors(H_{n-1}(M, \mathbb{Z})) = 0$. If nonorientable, then $H_n(M, \mathbb{Z}) = 0$, $Tors(H_{n-1}(M, \mathbb{Z})) = \mathbb{Z_2}$.  Now note by Poincare duality and UCT we have that $H_2(M) \cong H^1(M) \cong \mathbb{Z^r} \oplus T_0 \cong \mathbb{Z^r}$.   In the nonorientable case consider the exact sequence:  $0 \longrightarrow H_2(M) \longrightarrow H_1(M) \longrightarrow H_0(M) \longrightarrow 0$  But we know $H_1(M) = \mathbb{Z^r} \oplus Z_2$ from the earlier theorem and $H_0(M) = \mathbb{Z}$.   Therefore $H_2(M) \cong ker(\mathbb{Z^r} \oplus Z_2 \rightarrow \mathbb{Z}) \cong \mathbb{Z^{r-1}} \oplus \mathbb{Z_2}$.   For the rest of the question I'm quite lost. Graphics file extensions and their order of inclusion when not specified When using 's \includegraphics you can specify the file extension or not. For generic use and perhaps portability, extensions are commonly dropped. The types of "approved" inclusions and their order of precedence depends on the driver/compiler being used. What are these driver-defaults?  Related: