System.debug is giving me null result
Why is this trigger finding a null value despite the field being populated?
From Wikipedia :     Suppose you're on a game show, and   you're given the choice of three   doors: Behind one door is a car;   behind the others, goats. You pick a   door, say No. 1, and the host, who   knows what's behind the doors, opens   another door, say No. 3, which has a   goat. He then says to you, "Do you   want to pick door No. 2?" Is it to   your advantage to switch your choice?   The answer is, of course, yes - but it's incredibly un-inituitive. What misunderstanding do most people have about probability that leads to us scratching our heads -- or better put; what general rule can we take away from this puzzle to better train our intuition in the future? General rule for partial fraction decomposition Sometimes after I fry something, I wash it immediately in water because it's a bit easier to wash (before the remains stick to the pan).  Does this damage the pan in any way? Interpretation of ROC curve I have a ROC curve like the figure below:   What can be inferred given this kind of curve in general?  What are the differences of states 1, 2 and 3 in the figure?  What causes the diagram to jump straight from state 1 to state 3? Most of the ROC curves on the internet look like the figure below: Calculate business days I need a method for adding "business days" in PHP. For example, Friday 12/5 + 3 business days = Wednesday 12/10.  At a minimum I need the code to understand weekends, but ideally it should account for US federal holidays as well. I'm sure I could come up with a solution by brute force if necessary, but I'm hoping there's a more elegant approach out there. Anyone?  Thanks. Finding places to play Magic the Gathering games A friend of mine recently got MTG for the XBox and is talking us into getting real cards.  I'm all up for starting but I dread the idea of playing the same two people over and over with no change epically since one of them is over competitive and exploits every loophole he can to win.  Does anyone know of any a reliable (not just google it) way to find places where people play MTG? Get date for monday and friday for the current week (PHP) Consequences of a master thesis with errors I finished my master thesis 6 years ago, since then I gained a lot of experience on my field and also in academia. I can say that in that time I was a "child" , very inexperienced. I think that also my advisor did not help a lot, and I tried to do  a lot of things by my own, without someone to really review my things. Despite that, I still received a good mention by the master committee on final results.   Some days ago, I just decided to read part of master thesis, and I just realized a big nightmare coming. I identified a lot of typos, some references errors, and some improvements that I should do, but I did not. The worst thing is that I wrote a paper to a conference with my master thesis results (and some errors are there). The conference is not a high impact conference, but still the paper has my name and is available for everyone...   As I am finishing my PhD studies for now, I am concerning a lot that situation. My dream and goal is to pursue a Professor career. So, my questions are: What are (or could be) the consequences of a master thesis and paper with errors (some minor and some major) in academia? Revoke degree after years by errors in master is possible ( I am concerning a lot this situation that I thought on it)? How can I minimize it (I thought that I can put a fixed version of my thesis and paper in the future, for instance on my personal website)? How those errors can impact me in a Professor recruitment process?  Sorry for the long text, I am blaming myself all the time, and really afraid about the possibilities since I know that Academia career is really competitive. Why use Chef/Puppet over shell scripts? New to Puppet and Chef tools. Seems like the job that they are doing can be done with shell scripting. Maybe it was done in shell scripts until these came along.  I would agree they are more readable. But, are there any other advantages over shell scripts besides just being readable? Difference between generalized linear models & generalized linear mixed models Are split infinitives grammatically incorrect, or are they valid constructs? Mark's generosity in this crisis seems to more than make up for his earlier stinginess.   Should those sentences always be avoided, or are there cases where they are valid? Let's assume that one has some HP printer and/or scanner and checked its support status on the corresponding page of HPLIP site - .  So one have the following information: the device Model name, Min. HPLIP Version and Driver Plug-in need.   What should one install to make Ubuntu fully support the HP printer and/or scanner? A friend recently got her ID stolen while she was in the Netherlands. She will soon need to fly to her home country Italy, but she doesn't know what to do.  What can one do in such a situation? As far as I know, since it's Schengen, you don't need an ID card to go through borders. On the other hand, this is air travel, so they always require it for security reasons.   Can she show another document that proves her nationality? A copy of the ID card? Anything? During self-study, I ran across the question of how many ways six numbers can be chosen from the numbers 1 - 49 without replacement, stipulating that no two of the numbers be consecutive.  I can obtain a simple lower bound by saying that, in the worst-case scenario, when you choose a particular number, there are now three numbers that cannot be chosen next.  For example, if I first pick 17, then I can't choose 16, 17, or 18 for the remaining choices.  This gives me the lower bound  $$\frac{49*46*43*40*37*34}{6!} = 6,773,770 \frac{8}{9}$$  This is about 48% of ${}_{49}C_6 =  13,983,816$.  The real answer must be bigger (and an integer).  I haven't found a way to calculate it, though.  The original problem asked to show that the probability of having non-consecutive integers when you choose six is greater than 50%, so if the problem is complicated to count exactly, better approximations that show the answer is above 50% would also be appreciated.   Of course, I can use a computer to do the counting, but I'm interested in learning what methods I'm missing. How to add text to end of line when pattern is matched? inputs:  line1 with the PATTERN that contains ( )  line2 with the PATTERN that contains ( )  lineN with the PATTERN that contains ( )    outputs:  line1 with the PATTERN that contains ( ) ; line2 with the PATTERN that contains ( ) ; ... lineN with the PATTERN that contains ( ) ;   I tried this:  find . -name "test.txt" -print | xargs sed -i "/PATTERN/ s/$)/); /g"   but it didn't work. Can I put a metal safe weighing 2000 lbs in a 12x12 room? I have a 12'x12' upstairs bedroom. Can a 2000 lbs safe be placed in that room? The dimensions would be the same size as a queen size bed (60"x80").  Can you supply the math in your answer.  Thank you in advance  Danny How does one prove that the Klein bottle cannot be embedded in $R^3$? I'm talking about smooth embeddings. I'm still a newbie with Linux but I'm trying to learn. I have two USBs, one is 4GB and has the ISO install of Ubuntu (I think it's called live, the one with maximum of 4GB of permanent storage) and got a 64gb usb to make a permanent full install on it. I installed it following  tutorial and everything looks fine (I had to create the EFI partition with the Terminal though) but it just won't boot, the live install boots without problems.   I'm using the school's computers which have the UEFI menu password protected so I can't access that and I won't have a laptop for like 3 weeks (main reason why I'm doing this). I tested it with a friend's laptop disabling the Secure boot but it still wouldn't boot. I also saw that some tutorials don't add the EFI partition so I tried without that one and still won't work. And I know it's not the 64GB usb not booting because I had a live install on it too before and it booted fine.  Please, I have been trying to make it work for two days now, any ideas? I can barely understand this stuff so if you could explain step by step that would be awesome. Removing minimize/maximize buttons in Tkinter Show that the sequence $a_0 = 1$, $a_{n+1 }= \sqrt{2+a_n}$ is monotonically increasing Given the sequence $a_0 = 1$, $a_{n+1}= \sqrt{2+a_n}$, how can I show that it is monotonically increasing?  I need it to show, that the sequence converges. I already proved boundedness but I can't figure out this last part.