I bought tickets to and from the US. And I wonder if they would cancel my tickets for the flight back if I miss my first flight.  PS It's just I accidentally bought tickets with a stopover in Toronto and it turns out (didn't see that coming) that I need a transit visa to Canada. And to me it looks like it would be cheaper to buy another ticket to the US (with no stopovers this time)  PPS My connection time in Toronto is 1 hr 40 min and I am required to have a transit visa. And I can get one sending my passport to London (nearest Canadian embassy where they have glue and paper to make visas). This is just ridiculous.
I was browsing flight price at Singapore Airlines website, and a one-way flight from SIN to SFO cost this much:    That's quite expensive. I tried browsing around and found that a return flight from SFO to SIN and back to SFO cost much cheaper:    It's really weird because the second ticket includes the exact same flight that cost 1900+, but it's almost half the price. The reason for this counter-intuitive situation is explained in the answers this question   If I am located in Singapore and my intention is to fly one-way to SFO, is it safe to book the flight in the second picture and only board SFO-SIN leg? Will they deny me because I miss the SIN-SFO flight?
What causes atoms to have their specific colors? git-upload-pack: command not found, when cloning remote Git repo I have been using git to keep two copies of my project in sync, one is my local box, the other the test server. This is an issue which occurs when I log onto our remote development server using ssh;  git clone me@me.mydevbox.com:/home/chris/myproject Initialized empty Git repository in /tmp/myproject/.git/ Password: bash: git-upload-pack: command not found fatal: The remote end hung up unexpectedly fetch-pack from 'me@me.mydevbox.com:/home/chris/myproject' failed.   (the file-names have been changed to protect the guilty... !)   Both boxes run Solaris 10 AMD. I have done some digging,  if I add --upload-pack=$(which git-upload-pack) the command works, (and proves that $PATH contains the path to 'git-upload-pack' as per the RTFM solution)  but this is really annoying, plus 'git push' doesn't work, because I don't think there is a --unpack= option.    Incidentally, all the git commands work fine from my local box, it is the same version of the software (1.5.4.2), installed on the same NFS mount at /usr/local/bin.    Can anybody help? How to bind RadioButtons to an enum? I've got an enum like this:  public enum MyLovelyEnum {     FirstSelection,     TheOtherSelection,     YetAnotherOne };   I got a property in my DataContext:  public MyLovelyEnum VeryLovelyEnum { get; set; }   And I got three RadioButtons in my WPF client.  &lt;RadioButton Margin="3"&gt;First Selection&lt;/RadioButton&gt; &lt;RadioButton Margin="3"&gt;The Other Selection&lt;/RadioButton&gt; &lt;RadioButton Margin="3"&gt;Yet Another one&lt;/RadioButton&gt;   Now how do I bind the RadioButtons to the property for a proper two-way binding? I have received an .rar which I wish to unpack as it contains something rather important to me that I need to really have now. However even though I can view the contents of the .rar archive in the Archive Manager, I am unable to extract it due to this error:    The archive should contain two folders within it, each though contain at least 10 audio files as well as a PDF file each (I don't know what the contents exactly should be except for there should be audio files in there, and the content I have described is what I can see from the Archive Manager's view). So the only thing I am left with except the error is one of the folders and one of the audio files, but it says it has 0 bytes in it.  So how exactly do I fix this problem? I am running Ubuntu GNOME 16.04.1 with GNOME 3.20.  Information Update:  In reply to a comment requesting the output from the dpkg -l unrar unrar-free command:  Desired=Unknown/Install/Remove/Purge/Hold | Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend |/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad) ||/ Name           Version      Architecture Description +++-==============-============-============-================================= un  unrar          &lt;none&gt;       &lt;none&gt;       (no description available) dpkg-query: no packages found matching unrar-free When a user is suspended, their account is reduced to 1 rep and all of his privileges are stripped. However, they can still join chat rooms.   This leads to various forms of possible abuse (all of which I've seen by suspended users):   Join/leave spams Expletives in profile messages Hold one sided conversations with users of the room via    Suspended users cannot be kicked, and even moderators can do very little (aside from completely removing the account, which is often overkill).  My proposal is to extend  for suspended users to one of two levels:   Prevent them from being shown in the user list at all. Strip their profile profile picture and description from the profile view visible from chat rooms (not from profile pages). What causes javac to issue the "uses unchecked or unsafe operations" warning Proving Cauchy condensation test Why does the series $\sum_{n=1}^\infty\frac1n$ not converge? Can someone give a simple explanation as to why the       $$\sum_{n=1}^\infty\frac1n=\frac 1 1 + \frac 12 + \frac 13 + \cdots $$   doesn't converge, on the other hand it grows very slowly?   I'd prefer an easily comprehensible explanation rather than a rigorous proof regularly found in undergraduate textbooks. As Scott Myers wrote, you can take advantage of a relaxation in C++'s type-system to declare clone() to return a pointer to the actual type being declared:  class Base {     virtual Base* clone() const = 0; };  class Derived : public Base {     virtual Derived* clone() const };   The compiler detects that clone() returns an pointer to the type of the object, and allows Derived to override it to return a pointer to derived.  It would desirable to have clone() return a smart pointer that implies transfer of ownership semantics, like the following:  class Base {    virtual std::auto_ptr&lt;Base&gt; clone() const = 0; };  class Derived : public Base {     virtual std::auto_ptr&lt;Derived&gt; clone() const; };   Unfortunately, the relaxation of the conventions does not apply to templated smart pointers, and the compiler will not allow the override.  So, it seems I am left with two options:   Have clone() return a "dumb" pointer, and document that clients are responsible for disposing of it. Have clone() return a smart base pointer, and have clients use dynamic_cast to save them to a Derived pointer if they need it.   Is one of these approaches preferred?  Or is there a way for me to eat my transfer of ownership semantics and have my strong type safety too? line of mathematicians guess their own hat color out of c colors There is a common problem in which a long line of N mathematicians are each given a hat that is either red or blue.  They cannot see their own hat but can see all in front of time and can hear any response. They must state their own hat color from the back of the line forwards and no information may be passed besides their guess.  They may have a planning session in advance.  What is the maximum number of correct guesses can they guarantee?  The answer is (look away if you don't know) $N-1$.  If, instead of 2 colored hats, we use $c$ different colored hats, how many can we guarantee?  Assuming $N&gt;&gt;c$  I believe the answer to be $N-c+1$ and have confirmed this for $c=2, 3$, and $4$.  I believe this should be simple to prove by using the concept of "$x$ formulas allow you to solve for $x$ variables" but I am not well versed enough in pure mathematics to answer this. I am working on binary classification problem, I try to evaluate the performance of some classification algorithms (LR,Decission Tree , Random forest ...). I am using  a cross validation technique (to avoid over-fitting) with AUC ROC as scoring function to compare the performance of the algorithms, but I am getting a weird results with Random forest and AdbBoost, I have a perfect AUC_ROC score (i.e. =1) despite the fact that the recall(TPR) and FPR of this algorithms are different from 1 and 0 respectively .  def FPR(y_true, y_pred):     tn, fp, fn, tp = confusion_matrix(y_true, y_pred).ravel()     result = fp / (fp+tn)     return result def FNR(y_true, y_pred):     tn, fp, fn, tp = confusion_matrix(y_true, y_pred).ravel()     result = fn / (tp+fn)     return result FPR_scorer = make_scorer(FPR) FNR_scorer = make_scorer(FNR)     def get_CrossValResults2(model,cv_rst,bestIndx):     best=pd.DataFrame.from_dict(cv_rst).iloc[bestIndx]     roc=&quot;{:.12f}&quot;.format(best['mean_test_roc_auc'])     acc =&quot;{:.0%}&quot;.format(best['mean_test_accuracy'])     prec =&quot;{:.0%}&quot;.format(best['mean_test_precision'])     rec =&quot;{:.0%}&quot;.format( best['mean_test_recall'])     f1 =&quot;{:.0%}&quot;.format(best['mean_test_f1'])     r2=&quot;{:.2f}&quot;.format(best['mean_test_r2'])     g_mean=&quot;{:.2f}&quot;.format(best['mean_test_gmean'])     pr_auc=&quot;{:.8f}&quot;.format(best['mean_test_pr'])     fnr=&quot;{:.0%}&quot;.format(best['mean_test_fnr'])     fpr=&quot;{:.0%}&quot;.format(best['mean_test_fpr'])     rst = pd.DataFrame([[ model, acc,prec,rec,fpr,fnr,f1,roc,pr_auc,g_mean,r2]],columns = ['Model', 'Accuracy', 'Precision', 'Recall','FPR','FNR', 'F1-Score','ROC_auc','PR_auc','gmean','r2'])     return rst        cross_val_rst = pd.DataFrame(columns = ['Model', 'Accuracy', 'Precision', 'Recall','FPR','FNR', 'F1-Score','ROC_auc','PR_auc','gmean','r2'])              scoring = {'accuracy':'accuracy','recall':'recall','precision':'precision','fpr':FPR_scorer,'fnr':FNR_scorer,'f1':'f1' ,'roc_auc':'roc_auc','pr':'average_precision','gmean':Gmean_scorer,'r2':'r2'}     param_grid = {'n_estimators': [200],               'max_depth': [80,90],               'min_samples_leaf': [2,3, 4],             'min_samples_split': [2,5,12],             'criterion': [ 'gini'],              'class_weight' : [class_weights], 'n_jobs' : [-1]}  clf = GridSearchCV(RandomForestClassifier(class_weight=class_weights), param_grid, cv=kfold,scoring=scoring,refit=refit)#Fit the model bestmodel = clf.fit(X,Y)       cross_val_rst = cross_val_rst.append(get_CrossValResults2(model='Random Forrest',bestIndx=bestmodel.best_index_,cv_rst=bestmodel.cv_results_),ignore_index=True) Primary Decomposition of $\mathbb{R^n}$ under T I have a question related to the Primary Decomposition Theorem for a vector space under a linear transformation.  The following question is a direct corollary of this theorem.  However, I wish to prove it without calling upon theorem.  I am currently studying for a comprehensive exam and ran across this question.  I never really felt comfortable with the proof I saw of the Primary Decomposition Theorem so I hoping with your help with this problem I will understand this particular problem and better understand that proof as I believe their proofs will be essentially the same techniques.   Question:  Suppose we have a linear transformation $T: \mathbb{R^n}\to \mathbb{R^n}$ with minimal polynomial $m(x)=f(x)g(x)$ and $f(x),g(x)$ are relatively prime.  Show that we can write $\mathbb{R^n}=M\oplus N$ where $M$ and $N$ are $T$-invariant subspaces s.t $f(x)$ is the minimal polynomial for $T|_M$ and $g(x)$ is the minimal polynomial for $T|_N$.   So I know that I want to use $M=ker(f(T))$ and $N=ker(g(T))$ but after that I really don't have much.  Since this isn't a homework problem for a class I am essentially looking for someone to present me a proof of this simpler question and walk me through their logic so that I can hopefully understand the general theorem and its proof.  Thanks in advance for the help! Show that both mixed partial derivatives exist at the origin but are not equal $$f(x,y) = \begin{cases} \displaystyle \frac{xy(x^2-y^2)}{x^2+y^2} &amp; \text{if } (x,y) \neq (0,0), \\ 0 &amp; \text{if } (x,y) = (0,0). \end{cases}$$ I tried finding both mixed partial derivatives but they ended up being the same for that function. I must be failing to take into account something dealing with the fact that it is piece-wise. I still need to show the mixed partial derivatives exist. How can I do all of this? How can I learn the basics of SharePoint 2013 in a few days? I have very little knowledge of SharePoint, and want to learn about SharePoint 2013.  Most of the resources that I've found are either about what's new in 2013, or they have a bunch of links to SharePoint 2010.  I also don't have the time to read a thousand page book.  A hundred or so would be fine.  Can anyone recommend a resource (site / book / video / tutorial) for a beginner to learn the basics of SharePoint 2013 in a few days?  I've downloaded a Kindle book, "Getting Started With SharePoint 2013."  It's perfect for absolute beginners, who just want to know how to upload &amp; download documents, but I'm looking for more than that. Convert XML/HTML Entities into Unicode String in Python How to interpret the coefficients from a beta regression? I have some data that is bounded between 0 and 1. I have used the betareg package in R to fit a regression model with the bounded data as the dependent variable. My question is: how do I interpret the coefficients from the regression? Double Negation in C++ Object not visible in render I have a model which you can see here (camera perspective).    In the second image, you can see how the render turned out.    I'm at my wit's end trying to figure our why it's not showing up in the render. If anyone needs more information, just ask and I'll get it to you. I've already checked the normals and they're not the cause. How to write a LaTeX package that bundles not only .sty and .cls files but also some logos in .pdf or .eps formats? I would like to make a LaTeX package with the following subdirs:   tex/latex/common (a common .tex file shared among beamer and letter) tex/latex/resources (lots of pdf and eps files with graphical resources) tex/latex/mybeamer (a custom beamer theme with 5 .sty files) tex/latex/myletter (a .cls file for a letter template)   I would like to package these files into a single LaTeX package that users could install in an easy way. I read about the .ins and .dtx files and I can see how to pack the .sty and .cls files but what about the extra graphics - the resources folder which contains several PDF and .eps files? How do I go about porting Ubuntu Touch to different devices?