Sample mean is always an optimal estimator of the mean?
Why is expected value of random variable equal to mean
Fortunately, I can still login with this email address that I have lost access to.  I have been searching around here for a way to update it to the current one I use.  I have found many answers.  But they all give instructions to click on something not displayed or in one case, a page that prompts me to login via another email I no longer have the password for. I need current up to date instructions on how to change my email address or add another email-based login for this same user name that I am posting this with. I am trying to prove the following: Let $R=\mathbb{Z}[i]$, $a, b \in \mathbb{Z}, ab \neq 0$. Show that $a+bi$ is an irreducible element in $R$ if and only if $a^2 + b^2 ∈ \mathbb{Z}$ is prime. Since $R$ is a Euclidean domain, irreducible elements are prime. I think this is relevant, but am stuck on where to go from here. Returning a const reference to an object instead of a copy I used osm2pgsql to import data into my PostgreSQL database and it put gave me the following 4 tables, planet_osm_point, planet_osm_line, planet_osm_polygon and planet_osm_roads.   I have looked at the schema for osm2pgsql and inside the planet_osm_point table there is a column 'way' of type point. I tried to query it as an array like it says in the documentation here ():     It is possible to access the two component numbers of a point as   though the point were an array with indexes 0 and 1. For example, if   t.p is a point column then SELECT p[0] FROM t retrieves the X   coordinate and UPDATE t SET p[1] = ... changes the Y coordinate. In   the same way, a value of type box or lseg can be treated as an array   of two point values.   Anyone know the correct query the planet_osm tables from osm2pgsql based on long/lat? For example if I wanted to retrieve the information for Big Ben (London) I would query along the lines of:      SELECT * FROM planet_osm_point      WHERE ST_Y(ST_Transform(way, 4326)) = '-0.12'        AND ST_X(ST_Transform(way, 4326)) = '51.5';   There is no error message, it comes out with the table names, but no data is output either. (Its an empty table). What am I doing wrong here?  Perhaps it is too precise, i.e. there are no coordinates that match it exactly? Perhaps I need to try being more general, say 51 &lt; long &lt; 52 and -0.5 &lt; lat &lt; 0. Although this would throw back multiple results so would not be quite as accurate. Well, you can see it for yourself. The badge multiplier is a bit misaligned. Can you fix this please? (I know it's kinda a minor issue but it's bugging me and it's somehow off)    If it helps, I'm using Chrome version 44.0.2403.125 m. (Also repro'ed on FireFox 39.0 and )    For no good reason, that's a screenie from 's profile page. Regarding the advanced edition of FTL:  If all of your crew dies but you have a cloning bay on your vessel, is it immediately game over, or does the cloning bay prevent that?  Is the game smart enough to know that a damaged cloning bay and a fully dead crew means you cannot recover, but a functional one (even if temporarily without power) could revive your crew?  Also, does this answer differ between hostile ships and your own ship?  (That is, do you get to capture and loot enemy vessels that have all dead crew but have a functional cloning bay?) Solving "The ObjectContext instance has been disposed and can no longer be used for operations that require a connection" InvalidOperationException I am new to pythontex. I could run simple python code. However, I get error with slightly complex things.  The error I get is following:  This is PythonTeX 0.16  ----  Messages for py:default:default  ---- * PythonTeX stderr - error on line 211:     File "&lt;outputdir&gt;\py_default_default.py", line 62       MW= 18e-3 u.kilogram/ u.mole                 ^   SyntaxError: invalid syntax  -------------------------------------------------- PythonTeX:  notes - 1 error(s), 0 warning(s)  C:\texlive\2018\bin\win32\runscript.tlu:803: command failed with exit code 1: python.exe c:\texlive\2018\texmf-dist\scripts\pythontex\pythontex.py notes.tex   Part of the code that has error is :  \begin{pycode} import math from pint import UnitRegistry u = UnitRegistry() alpha = 0.04 sigmaW = 72.86e-3 * u.newton / u.meter mu    = 8.9e-4 * u.pascal * u.second densityW = 1000 * u.kilogram / (u.meter ** 3) densityIPA = 1000 * u.kilogram / (u.meter ** 3) densityEtoh = 1000 * u.kilogram / (u.meter ** 3) H = 1e-6 * u.meter W = 28e-6 * u.meter L= 32e-6 * u.meter MW= 18e-3 u.kilogram/ u.mole MIPA= 60.1e-3 u.kilogram/ u.mole MEtoh= 46.07e-3 u.kilogram/ u.mole R0=8.31446 u.joule / (u.mole * u.kelvin) T0= 298 u.kelvin N= 10 D0=2.4e-5 (u.meter ** 2)/(u.second) C0=17.08e-3 u.kilogram/(u.meter ** 3) tauevW=(densityW * N * R0 * T0 * (W **3))/(6* math.pi * D0 * C0 * sigmaW * MW) \end{pycode}   Does anyone know how to solve this issue? Grep in couple thousands files I have directory with cca 26 000 files and I need to grep in all these files. Problem is, that I need it as fast as possible, so it's not ideal to make script where grep will take name of one file from find command and write matches to file. Before "arguments list too long" issue it took cca 2 minutes to grep in all this files. Any ideas how to do it? edit: there is a script that is making new files all the time, so it's not possible to put all files to different dirs. Objective-C - When to use 'self' I am trying to install ia32-libs on Ubuntu 12.04 LTS (x86).  I enabled all the repository sources but I'm receiving the error message below:  ~$ sudo apt-get install ia32-libs   Reading package lists... Done   Building dependency tree          Reading state information... Done   Package ia32-libs is not available, but is referred to by another package.   This may mean that the package is missing, has been obsoleted, or   is only available from another source    E: Package 'ia32-libs' has no installation candidate   output of sudo apt-cache policy ia32-libs    ia32-libs:     Installed: (none)     Candidate: (none)     Version table:     output of cat /etc/apt/sources.list  (removed similar hyperlinks)    deb http://archive.ubuntu.com/ubuntu/ precise restricted main multiverse universe   deb-src archive.ubuntu.com/ubuntu/ precise restricted main multiverse universe #Added by software-properties   deb security.ubuntu.com/ubuntu/ precise-security main restricted universe multiverse   deb-src security.ubuntu.com/ubuntu/ precise-security main restricted universe multiverse #Added by software-properties   deb archive.ubuntu.com/ubuntu/ precise-updates main restricted universe multiverse   deb-src archive.ubuntu.com/ubuntu/ precise-updates main restricted universe multiverse #Added by software-properties How can I assign a Func conditionally between lambdas using the conditional ternary operator? I have created an FME workspace which inputs a pipeline as well as other linear features which cross it (waterways, roads, railways, fences, other pipelines, etc).  The output is a point file which contains the crossing type.  What I would like to do is calculate the distance along the pipe from the start of the pipeline for each intersection.  So, as you travel along the pipeline, the distance attribute will increase.   I'm thinking that I'll need to use some of the linear referencing tools like MeasureGenerator, MeasureExtractor, or something like that, but I'm not sure how to do so.  Does anyone have an idea of how to do this? What does this red icon on my panel mean? This red icon.... It showed up after I upgraded to Ubuntu 12.04LTS; I can't figure out how to ditch it. It seems to be a notification thing.  I am at a loss.  The icon is this one:      I clicked it and read this:     An error occurred, please run Package Manager from the right-click menu or apt-get in a terminal to see what is wrong. The error message was:  'Error: BrokenCount&gt;0'.        This usually means that your installed packages have unmet dependencies. block all but a few ips with firewalld On a linux  networked machine,  i would like to restrict the set of addresses on the "public" zone  (firewalld concept), that are allowed to reach it. So the end result would be no other machine can access  any port or protocol, except those explicitly allowed, sort of a mix of     --add-rich-rule='rule family="ipv4" source not  address="192.168.56.120" drop'    --add-rich-rule='rule family="ipv4" source not  address="192.168.56.105" drop'   The problem above is that  this is not a real list, it will block everything since if its one address its blocked by not being the same as the other, generating an accidental "drop all" effect,  how would i  "unblock" a specific non contiguous set? does source accept a list of addresses? i have not see anything in my look at the docs or google result so far.     EDIT: I  just  created this:  # firewall-cmd  --zone=encrypt --list-all encrypt (active)   interfaces: eth1   sources: 192.168.56.120   services: ssh   ports: 6000/tcp   masquerade: no   forward-ports:    icmp-blocks:    rich rules:    But i can still reach port 6000 from  .123   my intention was that   if a source is not listed, it should not be able to reach any service or port Search across Stack Exchange sites in Android app Importing 3D DXF file into QGIS with z information as attribute value? I have a dxf file of 3d contours. after import it does have only  layer,x,y attribute and doesn't have Z attribute.  How can I provide Z attribute to create a TIN file? 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. Problems with Curve Modifier What control type should I use - Image, MediaElement, etc.?