I saw a similar type of question in this forum but let me tell you my data point is far less than the data mentioned in that my data points are very less compared to other posts. I have only 20 data points. I need to do forecasting using that data in R. Can you please suggest some forecasting technique using such a small data? I tried to take 19 observation as training and 1 observation to validate &amp; fitted an auto.arima model but while I'm trying to predict it for 1 time period ahead I'm getting prediction as null.
I have a question related to modeling short time-series. It is not a question , but how. What method would you recommend for modeling (very) short time-series (say of length $T \leq 20$)? By "best" I mean here the most robust one, that is the least prone to errors due the fact of limited numbers of observations. With short series single observations could influence the forecast, so the method should provide a cautious estimate of errors and possible variability connected to the forecast. I am generally interested in univariate time-series but it would be also interesting to know about other methods.
Can I force WordPress to use  instead of ? Does anyone know of any good tools (I'm looking for IDEs) to write assembly on the Mac. Xcode is a little cumbersome to me.  Also, on the Intel Macs, can I use generic x86 asm?  Or is there a modified instruction set? Any information about post Intel.  Also: I know that on windows, asm can run in an emulated environment created by the OS to let the code think it's running on its own dedicated machine. Does OS X provide the same thing? Do lure modules and incense cause new pokemon to spawn near you, or existing pokemon to be drawn to you? When did Tom Riddle get his new face? Recently I asked about the  pertaining to Voldemorts new face. However I was corrected by ...     Well, I think the confusion comes with mixing movie canon with book canon. In Philosopher's Stone, here's what Harry sees when Quirrell unwraps his turban:           Harry would have screamed, but he couldn’t make a sound. Where there should have been a back to Quirrell’s head, there was a face, the most terrible face Harry had ever seen. It was chalk white with glaring red eyes and slits for nostrils, like a snake.          Philosopher's Stone - page 212 - UK - chapter 17, The Man With Two Faces      So it seems at some point between leaving school, and sticking his face to the back of Quirrel's head possessing Quirrel he got a new face some how.   How did he manage that? Is it some dark magic he applies? Is it from possessing snakes in Albania? What is the closed formula for finding      $$ \sum_{i=0}^{k} \binom{n}{2i}=?\quad ,k\leq \lfloor{n/2}\rfloor $$   I need summation only up to some intermediate  $k$ where $k\leq \lfloor{n/2}\rfloor$ .  SAY I need a closed formula to calculate $\binom{8}{0}+ \binom{8}{2}+\binom{8}{4} +\binom{8}{6}$  HERE $n=8$ and $k=6$ How can I know when my computer running Windows 7 was last restarted?   I prefer a solution that doesn't involve searching the event log, but something like wmic or maybe cmd commands. There is a $C > 0$ such that $\vert f(z)-f(w)\vert \leq C\vert z-w\vert$ for a holomorphic map into $B(0, R)$. Let $0&lt;\delta&lt;r$ and $R&gt;0$, and $a\in\mathbb C$. I want to show that there exists $C&gt;0$ such that for all holomorphic functions $f\colon B(a,r)\to B(0,R)$, we have $$ \vert f(z)-f(w)\vert\leq C\vert z-w\vert $$ for $z,w\in B(a,\delta)$.  I'm not sure how to approach this. I was wondering if I could use that $$ \left\vert\frac{f^{(n)}(a)}{n!}\right\vert\leq\frac{\Vert f\Vert_{C(a,\rho)}}{\rho^n} $$ for some $0&lt;\rho&lt;r$. I also have an expression from biholomorphic maps from $B(0,1)$ to itself, but I'm not sure if I could use that here. Any hints? When a player joins the server, this command block (containing gamemode 2 @a) puts them into gamemode 2/adventure mode. How can I change this so that only non-admin/not "opped" players' gamemode gets changed? I have been around on Twitter for awhile and I regularly find people using "Please to retweet this" or "Please to help me", etc. Is this proper English? I do not think prefixing the infinitive form with a 'to' is necessary here at all. Software was blocked from opening because it is not from an identified developer I went to run LibreOffice on my OS X 10.9 and it would not let me install it. It said it was from an unidentified developer. I'm aware of the security features of the Mac and went to System Preferences to allow the software to run.   When I opened this setting I saw a button that said, '"LibreOffice" was blocked from opening because it is not from an identified developer.' and there was a button next to it that said "Open Anyway". I clicked this button and nothing happened. I clicked it multiple times, like a hundred, out of frustration. Is there something else I need to do? Could someone verify this is not a bug?   UPDATE: I've included the photo below of what my System Preferences screen looked like and the button I pushed that didn't work.  UPDATE II: So I tried opening the application again and went into the system preferences and pressed the "Open Anyway" button again and nothing happened at first but a few minutes later while I was typing an email something flashed across my screen, possibly another dialog (or more likely a chewpacabra), but it quickly disappeared and the next thing I know LibreOffice launched! Speed of neutrinos Everyone knows it is close to $c$, but how close? What are the recent results? "I'm right, aren't I?" My dictionary reports that aren't is also an abbreviation for am not, when used in questions.  Is this use of aren't common? If it is common, are there any differences between the different English dialects?     Why aren't I being given a pay raise? Space ship manned by only AI returns home to a different earth, back in time So the complex number z is given as   $z=1-cos(2\theta)-isin(2\theta)$  And the question is to find the argument of z in terms of $\theta$.   So, I used the formula for calculating the argument of a complex number:  $arg(z)=arctan (\frac{sin(2\theta)}{1-cos(2\theta)})$  $=arctan (\frac{2sin\theta cos\theta}{1-(1-2sin^2\theta)})$  $=arctan (\frac{2sin\theta cos\theta}{2sin^2\theta})$  $=arctan (\frac{cos\theta}{sin\theta})$  $=arctan (cot\theta)$  $=arctan (tan(\frac{\pi}{2}-\theta))$  $=\frac{\pi}{2}-\theta$  But apparently the answer is $\theta-\frac{\pi}{2}$.  Where might have I gone wrong?  Edit: the domain given in the question for $\theta$ was $0≤\theta≤\pi$ How to parse hundred html source code files in shell? Duplicity Backup Browse I have made a duplicity backup with Ubuntu 14.04 in another laptop of my home directory.  I copied all duplicity back files to my current laptop to "/home/user/Ubuntu-backup"  How do i browse the content of that backup see if it is worth restoring? I want to restore how do i restore from those files. How to stop creating .DS_Store on Mac? Strategies to denest nested radicals $\sqrt{a+b\sqrt{c}}$ I have recently read some passage about nested radicals, I'm deeply impressed by them. Simple nested radicals $\sqrt{2+\sqrt{2}}$,$\sqrt{3-2\sqrt{2}}$ which the later can be denested into $1-\sqrt{2}$. This may be able to see through easily, but how can we denest such a complicated one $\sqrt{61-24\sqrt{5}}(=4-3\sqrt{5})$? And Is there any ways to judge if a radical in $\sqrt{a+b\sqrt{c}}$ form can be denested?  Mr. Srinivasa Ramanujan even suggested some CRAZY nested radicals such as: $$\sqrt[3]{\sqrt{2}-1},\sqrt{\sqrt[3]{28}-\sqrt[3]{27}},\sqrt{\sqrt[3]{5}-\sqrt[3]{4}}, \sqrt[3]{\cos{\frac{2\pi}{7}}}+\sqrt[3]{\cos{\frac{4\pi}{7}}}+\sqrt[3]{\cos{\frac{8\pi}{7}}},\sqrt[6]{7\sqrt[3]{20}-19},...$$ Amazing, these all can be denested. I believe there must be some strategies to denest them, but I don't know how.  I'm a just a beginner, can anyone give me some ideas? Thank you. How to draw arrows between parts of an equation to show the Math Distributive Property (Multiplication)? There is a part of my paper where I use the distributive property and it might not be clear to the reader to see the operation result (I'm using in proposional logic for a proof). The logic equation (part of) is: $$ (l_{1}) \vee \big( (p \vee q) \wedge (\neg p \vee q) \wedge (p \vee \neg q) \wedge (\neg p \vee \neg q)\big) $$ $$ (l_{1} \vee p \vee q) \wedge (l_{1} \vee \neg p \vee q) \wedge (l_{1} \vee p \vee \neg q) \wedge (l_{1} \vee \neg p \vee \neg q) $$  So I was wondering if there is a way to represent this operation like a 'shower' (see another example in pic ). Maybe there is some hidden magic mathmode command or pkg for this. At last we can also rely on tikz. U.K visitor visa with very old criminal conviction - do I disclose it? I have been travelling to the U.K for 25 years at least 8-10 times a year,  receiving 5 year visas, never breaking the stay period, with no problem. I've gone through immigration with no problem till my last time in London. I was stopped for eight hours and questioned about a run with the law while I was in college. This was in the US, I was around 20, it was for a credit card use. I received a conditional discharge / probation conviction which was discharged one year later. It was stupid, I was young and in college, more than 28 years ago.  After being questioned about the issue in the US, I was allowed in. They were very polite and professional.  I was also asked if I ever changed my name: I did not change it, but one letter was added in the middle of my first and last names around 20 years ago as our names are translated from Arabic to English and before the digital biometric passports, hand written passports some times varied. It was a common thing at the time.  Now I am applying for my new 5 year visas and I intend to answer truthfully  about previous conviction (previously I answered no because my conviction was spent and I expunged my record.) I want to answer yes and explain it. Is that the right thing to do?  Should I answer yes to the question about having a different name even though it was something as simple as spelling Bryan instead of Brian or Teresa and Theresa -- not really changing it and never thought of it as a change.  I have an impeccable credit rating in the Uk and the last 28 years have never received a moving violation or ever had a run in with the law.  I made one mistake when I was very young but I am  very worried about how to go ahead. I believe honesty is the best approach, is it?