JS how to check empty String and Space
How can I check for an empty/undefined/null string in JavaScript?
Variable importance from GLMNET If matrix $A$ is unitary and $B^2=A$, is $B$ necessarily unitary? Stack Exchange- Area 51 Android App I am trying to use Stack Exchange Andoid App to use my accounts in Stack Overflow &amp; Area 51.   For the Area 51, there is only Area 51 Discussion. Even Area 51 Discussion isn't working in the App!   VERSION 1.0.51  When adding this site, it's showing the correct full name as in this screen-shot:     However, when I pin this site to my fav sites in Stack Exchange, it is showing: Unknown Site. When clicking it, it shows black screen then just quit the App!  Here is the screen-shot:       Is the site not yet capable with Android? or is it a bug in the App itself?  PS: this question isn't duplicate:   In the previous versions of the App, the site was opening but with Unknown Site name. However, in this version, it quits the app when pressing the area site! It isn't opening at all! This question is also to track this bug in the App. As it's about the site name issue &amp; the content as well. Filter dict to contain only certain keys? Help me understand adjusted odds ratio in logistic regression I've been having a hard time trying to understand the use of logistic regression in a paper. The paper available  uses logistic regression to predict probability of complications during cataract surgery.   What is confusing me is that the paper presents a model that assigns odds ratio of 1 to baseline described as follows:     A patient whose risk profile was in the reference group for all risk indicators (ie adjusted OR=1.00 for all in Table 1) may be regarded as having a ‘baseline risk profile’, and the logistic regression model indicates a ‘baseline predicted probability’ for PCR or VL or both=0.736%.   So the probability of 0.00736 is presented with odds ratio of 1. Based on the transformation from probabilities to odds ratios: $o=\frac{p}{1-p}$, this can't be equal to 1:  $0.00741=\frac{0.00736}{1-0.00736}$.  It gets even more confusing. The composite odds ratios that represents multiple covariates having values different than the baseline is used to calculate predicted risk.      ...the composite OR from Table 1 would be 1.28 X 1.58 X 2.99 X 2.46 X   1.45 X 1.60 = 34.5, and from the graph in Figure 1, we see that this OR corresponds with a predicted probability of PCR or VL or both of around 20%   The only way to arrive at the values the paper is giving as examples is to multiply the baseline probability with composite odds like this: $0.2025=\frac{(34.50\ \times\ 0.00736)}{1\ +\ (34.50\ \times\ 0.00736)}$.  So what is going on here? What is the logic for assigning odds ratio 1 to a baseline probability that is not 0.5? The update formula I've came up with above comes up with the right probabilities for examples in the paper but this is not the direct multiplication of odds ratio I'd expect. What is it then? I'd like to understand  and its contents as to what it implies in a bit simpler terms. I am familiar with mathematics unto Calculus 1,2,3 and some linear algebra and group theory. I am familiar with that for each symmetry there is a conservation law.    Now is there a one-one correspondence between these two always? What about laws like conservation of charge?  And conservation of energy?  And conservation of mass?  Considering our view of nature was changed as Special Relativity was introduced and thus, what earlier the theorem would have asserted as mass and energy to be originating from different symmetries then how did we reconcile these two as just one symmetry? Embedded quotes in arcpy.CalculateField_management expression I'm using arcpy.CalculateField_management to populate a field.  The expression:  "'https://anystate.gov/someportal/DisplayQueryResults.aspx?Prompts=Spill%20Number="!ID!"&amp;Database=OfficeDocs&amp;Query=DEP_Spill_Projects&amp;QuerySet=Portal_Queries&amp;User=Portal.DEP&amp;Password=DEPPortal1'"   will work when entered into the Calculate Field Tool.  The url is completed by pulling in values from the ID field.  However, the Python code snippet pasted into my script results in a syntax error. It's worth noting the expression is bounded by """"'....'"""" (4 double quotes outside a single quote.  I tried Midavalo's suggestion a couple of different ways. First attempt set  expression = 'https://anystate.gov/someserver/…{0}&amp;Database=OfficeDocs&amp;Query=DEP_Sp‌​ill_Projects&amp;QuerySe‌​t=Portal_Queries&amp;Use‌​r=Portal.DEP&amp;Passwor‌​d=DEPPortal1'.format‌​(!ID!)   Resulting in invalid syntax  Based on the Python link, the second try included single quotes:   'https://....'.format('!ID!')    But the result was a syntax error I am trying to import an Excel table with around 10,000 XY points into ArcMap 10.2. I am using State Plane NAD 1983 Alabama West (US Feet) as the Coordinate System in my map data frame. I then add the excel table to my Table of Contents in the map then select Display XY Data. Next, I choose the same coordinate system as my data frame then select OK. Once it creates the Events layer for my points they are not in the correct location.   Should I switch everything in my map to WGS84 or is there a solution for my points to be added onto my current map with the state plane coordinate system? I have noticed after deleting an original page in WordPress with lets say a permalink of your_domain.com/contact/ and then trying to recreate the same page with the same name/slug, my WP is generating a "-2" at the end of the link, like: your_domain.com/contact-2/.  I don't understand why, since the original page was deleted. Why is WordPress treating new pages as if the original still exists? How to I clean WP caches, if such a thing even exists?Thank you ahead of time for clearing this up for me. MacBook Pro - FaceTime HD Camera - Hardware "Failure'? System Report>Camera>No video capture devices were found     USB>Device Tree> No FaceTime HD Camera (inbuilt)listed    What can be the cause for "camera hardware failure"? Could faulty iSight cam wifi antenna cable linkage between logic board and camera board (in display)result in Camera hardware not "found"? Dynamic Table partitioning on a daily basis I have a SQL Server database which contains two tables -- Acks and Logs.  These two tables are related in logic but not in a relational database way. Basically, every message that comes in gets saved in the Log table and, if our server acknowledges it, then that ack gets stored in the Ack table.  We are storing around 5 million Acks and 3 million Logs a day. I am trying to partition these two tables on a daily boundary so that we can easily remove older partitions from the table, and also improve query performance.  I haven't done table partitioning before, so I have been reading some on-line tutorials, however I am stuck on one thing. All the tutorials I have followed seem to manually add filegroups and manually add boundaries.  I want SQL Server somehow to do this daily, and this is what my question is about. I need it to create the new filegroups for the next day, every day at, say, 22:00. Then at 24:00 the inserts should start filling up the new day's partition.  Can anyone point me in the right direction on how to achieve this? Either a comprehensive tutorial or some good old advice will do as well.  My second question: can I somehow apply the same partition function to the two different tables?  They both have a datetime(2) column on which I want to partition, and the same rules  will apply.  How does that then fit in with my filegroups? Do I need a single filegroup for the day? Will each table have a file in that filegroup, or will both tables save to the same file in the filegroup?  Do I have to make a .mdf and .ldf for each filegroup? Or is there still one log file for the entire database? Identifying a short story about advertising com.google.android.trichromelibrary causes many Android apps to crash Recently, apps that are fine an hour ago now crash when I open them. The crash report message seems to be caused by a null pointer exception (NPE) in com.google.android.trichromelibrary. Apps affected for me:  Gmail Dashlane  Is it just me, or is there actually something wrong with the library? How can I fix these affected apps? Crash report: *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** Build fingerprint: 'Xiaomi/polaris/polaris:10/QKQ1.190828.002/20.9.4:user/release-keys' Revision: '0' ABI: 'arm64' Timestamp: ... pid: ..., tid: ..., name: com.dashlane &gt;&gt;&gt; com.dashlane &lt;&lt;&lt; uid: ... signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr 0x0 Cause: null pointer dereference          ...  backtrace:     #00 pc 00000000038621f0 /data/app/ com.google.android.trichromelibrary 438909034-YaxP9ttrIDcQBfleP5vm7Q==/base.apk! libmonochrome_64.so (offset 0x646000) (BuildId: ... )  (click  for the screenshot of the bug report) When in a group chat, if many messages are exchanged between other people in the group, when I check my Whatsapp, the messages are grouped according to sender and not chronologically. I know that my phone isn't the problem as I have recently changed my phone, however, I'm still experiencing the same problem.  I have tried uninstalling and re-installing WhatsApp on my phone, and the same problem still occurs. Editing old questions can't read from SQlite database Using equations to draw out complex objects How do people come up with equations of curves to draw out complex objects?  Some popular examples would include:  &amp;  .  This  explains the rationale for the batman curve nicely.  But other than trial and error, I can't see a reasonable way of drawing the much more complicated PSY curve. Differences in meaning when the verb tense changes (headlines) What is the difference between the examples below?  Generally, in a newspaper, news is based on past tense (things which have already happened).   Then why are headlines written in ways that says: He Kills (shouldn't it be: He Killed)?  For example:  Parliament passes bill vs. Parliament passed bill  Also  He kills his friend vs. He killed his friend  Please help. Quantum Hall effect for dummies In the past few days I've become increasingly intrigued by the QHE, mainly thanks to very interesting questions and answers that have appeared here. Unfortunately, I am as of yet very confused by all the (seemingly disparate) stuff I learned.  First, here are some random points that I've been able to gather   I(nteger)QHE occurs due to the presence of Landau levels IQHE is an embodiment of topological order and the states are characterized by the Chern number that tells us about topologically inequivalent Hamiltonians defined on the Brillouin zone IQHE requires negligible electron-electron interations and so is dependent on the presence of impurities that shield from Coulomb force F(ractional)QHE occurs because of formation of anyons. In this case Coulomb interaction can't be neglected but it turns out an effective non-interacting description emerges with particles obeying parastatistics and having fractional charge FQHE has again something to do with topology, TQFT, Chern-Simons theory, braiding groups and lots of other stuff FQHE has something to do with hierarchy states   So, here are the questions        Most importantly, do these points make sense? Please correct any mistakes I made and/or fill in other important observations   How do explanations 1. and 2. of IQHE come together? Landau quantization only talks about electron states while topological picture doesn't mention them at all (they should be replaced by global topological states that are stable w.r.t. perturbations)   How do explanations 4., 5. and 6. relate together   Is there any accessible introductory literature into these matters?   Do IQHE and FQHE have anything (besides last three letters) in common so that e.g. IQHE can be treated as a special case? My understanding (based on 3.) is that this is not the case but several points hint into opposite direction. That's also why I ask about both QHE in a single question How much marmelade can I bring into the US? I want to bring homemade berry marmelade in little glass jars with me to the US from Europe as gifts for friends. I have found the following site on importing foods into the US  and would assume that marmelade falls under the condiments category, which should be admissible. However, I am wondering however if there is any limit to how much one is allowed to bring. Will there be any issues if, say, I bring 3 kilograms (6 lbs 10 oz)?   Also on related note, would they be suspiscious when they see many glass jars in my bag? Do I risk getting my bag searched or getting asked what the jars are? Is there anything I can do to avoid any such trouble?