Ternary Operator syntax to choose implementation of Interface
Implicit conversion issue in a ternary condition
I already have the "Edit Questions And Answers" privilege. Yet, if I approve someone else's edit, I'm told that more votes will be required before the edit is accepted.  This seems a bit peculiar to me, since I could just copy the edited version and paste it myself. Which "mean" to use and when? So we have arithmetic mean (AM), geometric mean (GM) and harmonic mean (HM). Their mathematical formulation is also well known along with their associated stereotypical examples (e.g., Harmonic mean and it's application to 'speed' related problems).  However, a question that has always intrigued me is "how do I decide which mean is the most appropriate to use in a given context?" There must be at least some rule of thumb to help understand the applicability and yet the most common answer I've come across is: "It depends" (but on what?).  This may seem to be a rather trivial question but even high-school texts failed to explain this -- they only provide mathematical definitions!  I prefer an English explanation over a mathematical one -- simple test would be "would your mom/child understand it?" SSH remote user need to be logged in? $n\ge 8\,\Rightarrow\, n = 3j + 5k\ $ for $\,j,k,n\in \Bbb N$ I'm new to Math Induction, I don't know how it goes from $𝑘 + 1 = 3𝑥 + 5𝑦 + 1$ into $5𝑦 = 5𝑦 − 5 + 5.$  I'm trying to prove that:   Any whole number of at least 8 cents can be obtained using coins of 3 and 5 cents  Assume: There is a number $𝑘$ for which there are $𝑥$ and $𝑦$ such that $𝑘 = 3𝑥 + 5𝑦$  Here's my working:  $𝑘 = 3𝑥 + 5𝑦$  Therefore $𝑘 + 1 = 3𝑥 + 5𝑦 + 1$  $5𝑦 = 5𝑦 − 5 + 5$  $5𝑦 = 5 𝑦 − 1 + 5$  $𝑘 + 1 = 3𝑥 + 5𝑦 + 1$  $𝑘 + 1 = 3𝑥 + 5(𝑦 − 1) + 5 + 1$  $𝑘 + 1 = 3𝑥 + 5(𝑦 − 1) + 6$  $𝑘 + 1 = 3(𝑥 + 2) + 5(𝑦 − 1)$  $𝒌 + 𝟏 = 𝟑𝒙' + 𝟓𝒚'$ Custom text color in C# console application? Give a one-to-one and onto function from $\mathbb{N} \times \mathbb{N}$ to $\mathbb{N}$ Storing datetime values in Shapefiles using QGIS? I have a shapefile with date in a string field. I create a new field with date type and use the calculator to make the conversion. But the result only provide the date part, the time part is removed. Even when the preview show the correct conversion.  Here you can see the original string field time and the result date time2. And the use of the conversion function to_datetime() and the preview result at the end    If you go to the layer properties you can change the edit mode to date/time. Then if go to the data and try to edit time2 you get the current date/time. So is possible save date and time in the same field. But the update tool still doesn't work as expected      As J.R said. Even when you can change QGIS edit to allow Date/Time the save to shapefile will discard the time. Can all real polynomials be factored into quadratic and linear factors? As my question says,   $$\frac 1{1.2.3}+\frac 1{2.3.4}+\frac 1{3.4.5}+...$$  As far as $\frac 1{1.2}+\frac 1{2.3}+\frac 1{3.4}+...$ is concerned, we can write it as $\frac 1{n-1} - \frac 1{n}$ What can we do here? The ls -al command shows the following output;  -rwxrw-r--    10    root   root 2048    Jan 13 07:11 afile.exe   What are all the fields in the preceding display? Can I register a domain name that contains a company name or trademark? I wonder is it legal to register a domain name that contains a company name. For example cococola.cc (considering that this domain name is available). Can I buy and use any domain names that contain a name of a trademark? Any solutions to Veritasium's hydrodynamic levitation? So this Youtube video has been around for a while now  . Also this  may be related.  I just wanted to know if there is any standard hydrodynamic terms to explain it. Derek clearly states it is not about Bernoulli principle, as in this case the ball rotation is important.  Has any recent paper/videos discussed what happens if you do the same experiment with hydrophobic spheres? Can it be predicted with laminar flow theories or does it need turbulence?  Too many questions have been posed, but not so many responses on the internet yet.  Edit: I said Derek stated "it wasn't Coandă effect", yet what he says is that it is not "just Bernoulli's principle". Coandă effect is the typical hairdryer ping-pong ball levitation which is explained by Bernoulli's principle.   Edit2: rephrasing.  Additional comment: There seems to be two explanations "water adhere to the sphere and is ejected conserving horizontal momentum" and "Magnus effect" (ME). The later is not so obvious to me as the system is in equilibrium and there are two fluids, water and air, (does ME means air pushes the ball horizontally?).   Edit3: DESCRIPTION To avoid rot links and people that do not want to see the video, I'll try to explain the phenomena. You have a sphere and a water jet. The water jet is vertical (opposite to gravity), and touches the sphere almost tangentially. The ball not only rotates due to the water jet but also stays at constant height from the ground. The angular velocity can be defined in the direction of the cross product between the position of the contact point between the jet and the sphere (origin in the center of the sphere) and the direction of the jet. Some water drops fly away at the top of the sphere away from the jet.  Edit4: New question, would this phenomenon occur if there was no air? I have to travel to Germany and Switzerland for business purpose. I have already been here 2 years ago. I have applied for business visa to the German consulate twice and both times the application got rejected. They have put a green stamp on the last page twice. The reason is the purpose and information submitted regarding intended stay is not reliable. I have submitted the documents to Swiss consulate and they have accepted and granted me a visa. Now I have to first travel to Germany and then to Switzerland.  So my question is, with a Schengen business visa granted by Switzerland, may I enter in Germany? Does the rejection stamp has any impact for entering at German airport ? Does it mean I cannot travel to Germany but to other Schengen countries ? What does the following for loop syntax mean in C? Given that $a$~$\mathcal{N}(\mu, \Sigma)$ and $\mu$~$\mathcal{N}(0, \sigma^2 I)$, Is $p(a|\Sigma, \sigma)=\int p(a|\mu, \Sigma)p(\mu|\sigma)d\mu$ again a Normal distribution? And how to estimate the mean and variance respectively? Thanks a lot! I'm having issues unlocking my Nexus 7 2013 WiFi's bootloader, and it was suggested that I try fastboot oem unlock-go instead of fastboot oem unlock. Both seem to act the same on my device, however both also fail on my device so it is possible that the difference appears after the failure on my end comes. Regardless, I would like to know: What is the difference between these two commands? I'm not managing to find documentation. How to keep the spaces at the end and/or at the beginning of a String? Why is feed-forward mechanism used in hash functions? The compression function of SHA-1 when used in Davies-Meyer mode adds its input to the chaining values at the final step. For the first message block, the IV is used as the input and in the next step, the previous block's output (as specified by Merkle-Damgård) is used. These values are fed to the last round of the compression function.  Why would removing the feed-forward part (i.e.,the final step where the input value is added to the result to get the final output) make the hash function insecure? Apart from the fact that the compression function would not satisfy desired randomness properties (being a permutation for each fixed message). I am in the process of updating my CV. Since I often get labeled as "the bioinformatician" I get to play with many different languages and technologies, and similarly what people expect from a bioinformatician varies from person to person. So I figured it would be a good idea to indicate how much I feel I know in respective fields/languages.  Inspired by , I came to wonder whether or not its acceptable to have self-assessed ratings of your technical skills, such as: proficiency programming languages, familiarity with relevant software etc.   My own feeling is that such ratings are useful to indicate what you feel most confident or comfortable with. It would also be useful to show any potential future employer the level of competence you have in different fields. If you think about it a bit, it is common to have some type of rating for the languages one speaks, so I think an analogue to programming language proficiency should not be that alienating.  On the other hand there is the risk of rendering your CV like, as a friend of mine put it, a role-playing game character sheet.   Is it common to have such ratings on skills? Are there any potential problems with it?   Edit: What I was thinking is a small listing something like: Splitting vector layer in R