Java postfix calculator push/pop method with a String[] array
What is a NumberFormatException and how can I fix it?
I have two separate Armatures that I want to join together. I have no problem combining the meshes, but the problem is the bones/rigs. When you do the Object mode > join, I lose all of my weight paint on one of my armatures. Is there any way I can join two separate armatures and keep all the weight paint. I turn my models into XPS and use XNA Lara to view them, but XNAlara cannot use both armatures at once. finding examples for a non negative and continuous function for which the infinite integral is finite but the limit at infinity doesn't exist Question:  a. Find an example for a non-negative and continuous function s.t. $\int _0^\infty f(x)dx$ is finite but the following limit doesn't exist: $\lim_{x\to \infty} f(x)$.  b. Is it possible that $\int _0^\infty f(x)dx$ is bounded but $f(x)$ is not bounded?  What we did with A: We suggested the function $|sin(x^2)|$ which has periods that get smaller and smaller until they no longer imply on the sum. But since it's a trig function it doesn't have a determinate limit. Wolfram didn't have the integral value for that func, and we were wondering if it really converges and if it is really a good example.  What we did with B: We thought about the function: $f(x)=  { x\in \Bbb N },{e^{-x} \notin \Bbb N }$ and we had a disagreement whether f(x) is integrable. I said no because similarly to Dirichlet function, one sum's limit will be 0 while the other one's will be infinite. My partner said that if I find a $\delta&lt;1$ then the definition of Riemann's integral does hold and so this integral is equal to that of $f(x)=e^{-x}$ She was trying to say this functions integral will be 0, but still it won't be bounded. I disagreed. Who's right? Sponsor Gallery, Page, or Something Like That? nhj asked the other day,  In , I wrote:     We were thinking of putting together a "sponsor gallery" of sorts that listed out all of the sponsors with a brief description. Kinda in the vein of what we have on the every-now-and-then  at TDWTF.   So, consider this the discussion for that topic.   What would you like to see in a sponsor gallery? Should it be one big, long list? How does the order get determined? Should we organize the sponsors based on tags (and if so, what about sponsors who target like java and .net)? What about former sponsors... do they get removed from the list, or go on like the "past sponsors" section/page?  Keep in mind that this is not something we intend to charge extra for... this is more a service to the you, the members, than anything else. I've gotten postive feedback from the TDWTF "gallery", as a lot of readers come through RSS, have adblock running, etc. Will $\sum^{\infty}_{n=1}|a_n|^p$ converge? Prove that the additive groups $\mathbb{R}$ and $\mathbb{Q}$ are not isomorphic. Is there a better (or other) way(s) to prove the following statement? Also, the same argument works for multiplicative groups $\mathbb{R}-\{0\}$ and $\mathbb{Q}-\{0\}$, right?       Problem Prove that the additive groups $\mathbb{R}$ and $\mathbb{Q}$ are not isomorphic.   Solution By cantor's diagonal argument, there is no possible bijection between $\mathbb{Q}$ and $\mathbb{R}$. Since an isomorphism needs to be a bijection, there is no possible isomorphism between the additive groups $\mathbb{R}$ and $\mathbb{Q}$.    Thanks Evaluating limit $\lim_{k\to \infty}\prod_{r=1}^k\cos{\left(\frac {x}{2^r}\right)}$ PHP mail function doesn't complete sending of e-mail How to insert an item at the beginning of an array in PHP? Closed-form expression for $\sum_{k=0}^n\binom{n}kk^p$ for integers $n,\,p$ Is there a closed-form expression for the sum $\sum_{k=0}^n\binom{n}kk^p$ given positive integers $n,\,p$? Earlier I thought of this series but failed to figure out a closed-form expression in $n,\,p$ (other than the trivial case $p=0$).  $$p=0\colon\,\sum_{k=0}^n\binom{n}kk^0=2^n$$  I know that $\sum_{k=0}^n\binom{n}k=2^n$ and $\sum_{k=0}^nk^n=\frac{k^{n+1}-1}{k-1}$ but I am unsure of whether these would be of much use now.    Additionally, what about the similar series $\sum_{k=0}^n\binom{n}kk^n$ where $p=n$? A generalization for Serret's integral $\int_0^a \frac{\ln(1+ax)}{1+x^2}dx$ Internal keyboard and trackpad stop working after plugging in USB device I got a new MacBook Pro with OS X Mavericks. When connecting my phone via USB, the internal keyboard and the trackpad immediately stop working -- not always but in most cases. The bluetooth mouse and an external USB keyboard are not affected. Everything else works also fine. The power button of the internal keyboard still works. Reboot helps. Any ideas? Several companies are commercializing tests for telomere length such as this one . I understand the basic mechanism for why telomeres shorten during DNA replication, but how good is the evidence that telomere length is a reliable indicator of healthspan/lifespan? How prove this nice limit $\lim\limits_{n\to\infty}\frac{a_{n}}{n}=\frac{12}{\log{432}}$ Nice problem:  Let $a_{0}=1$ and $$a_{n}=a_{\left\lfloor n/2\right\rfloor}+a_{\left\lfloor n/3 \right\rfloor}+a_{\left\lfloor n/6\right\rfloor}.$$  Show that  $$\lim_{n\to\infty}\dfrac{a_{n}}{n}=\dfrac{12}{\log{432}},$$  where $\lfloor x \rfloor$ is the largest integer not greater than $x$.  It is said this problem was created by Paul Erdős, and I can't find this problem's solution, does anyone have any nice methods? Thank you. How to prove this is a metric? I have 2 distance functions $d(x,y)=|x^2-y^2|$ and $d(x,y)=|x^3-y^3|$ and I am trying to prove that they are metrics on $\mathbb R$, or give a counterexample that they are not metrics on $\mathbb R$.  I managed to prove the first 3 properties for the 2nd function namely:   $d(x,y)\ge0$ $d(x,y)=0$ iff $x=y$ $d(x,y)=d(y,x)$   and I now have shown that the 1st function is not a metric.  But for the triangle inequality property, $d(x,y)\le d(x,z) + d(z,y)$, Im stuck on it. How would go about proving it for $d(x,y)=|x^3-y^3|$? Thanks. Prove that if $n \in \mathbb{N}$, then $$\sum_{d|n}{(d(n))^3}=(\sum_{d|n}{d(n)})^2$$ where $d(n)$ is the divisor function. I have know only information is $d(n)=\sum_{d|n}{1}$. Simple examples of uncorrelated but not independent $X$ and $Y$ Any hard-working student is a counterexample to "all students are lazy".  What are some simple counterexamples to "if random variables $X$ and $Y$ are uncorrelated then they are independent"? What is the logic behind the timer of the Sojourner Badge? I came across the following question:    This can be easily flagged for too broad or opinion based, but I wonder on which stack-exchange site can one ask answers for such a question? What is port forwarding and what is it used for? There are a lot of questions on , but there doesn't seem to be one that clearly states what it is and what it's used for. So:   What is port forwarding? What is it used for, and why would I need it? I can't seem to find a story related to mine so here it is.  I am 25 and a German citizen. In 1998 when I was 7 years old my family moved to the states and we stayed until early 2002 and left voluntarily. Basically we overstayed. I am aware that my parents had the ten year ban and since I was a minor at the time of our overstay I did not receive such ban.  Ever since 2002 I have not attempted to go back to the USA for any reason. However now that I am older I would like to go back for vacation and stay for a short period of time (one month) during my christmas break.  I've lived in Germany since leaving, have a great job, enough money in the bank account. My whole life is here and I have no intention on moving anywhere else.  After reading a bunch of stories online I have decided to apply for a B2 visa to be on the safe side but I was curious about the ESTA approval. For the last question. 8) Have you ever stayed in the United States longer than the admission period granted to you by the U.S. government?   I should put yes but is it a no if I stayed when I was a minor? And what are my chances on getting the B2 Visa?