Log transform with 'zero' values I am doing some explorative work on two large datasets. One from 2001 and one from 2018. The dataset consists of measured soil-parameters and it contains lots of zero's.   From the transformations done in 2002 on the 2001 dataset, I have some notes written on the sideline of a LOGtransform graph: 'dataset contains '0'-values, 2 is highest number in column, so LOG(data+0.1)'.  The result of this transformation:    My Question: Where does this 0.1 come from in relation to the 2 (highest number in column, dataset)? What is this transformation called and what is the idea behind this kind of log transform?  I have the same skewness in my 2018 dataset, but the LOG(data+0,1) does't work as well. Also, can I compare the two with Repeated Measures ANOVA when the two log transformations have different numbers added to the data?
How should I transform non-negative data including zeros? If I have highly skewed positive data I often take logs. But what should I do with highly skewed non-negative data that include zeros? I have seen two transformations used:   $\log(x+1)$ which has the neat feature that 0 maps to 0. $\log(x+c)$ where c is either estimated or set to be some very small positive value.   Are there any other approaches? Are there any good reasons to prefer one approach over the others?
Account not acting as an administrator correctly My account, david, is in the Administrators group on a Windows 7 machine.  I am still having problems with programs that I should be able to use, such as SQL Server. Specifically, my account seems to not have correct permissions when I am working.  I know with an Administrator account I should have full access. How can I force my account (david) to act like an admin account and have full access to everything? Replace unknown reference (?) with the tag from \ref or \cite says:     squinch (skwɪntʃ)      (US)      transitive verb         to squint (the eyes); squinched up her eyes in disgust.               2.         a. to pucker or screw up (the face, nose, brow, etc.); Jonathan squinched his face into a grimace.       b. to squeeze or compress; She squinched the paper up in an angry twist and stood to throw it into the stove ; Robert squinched the ketchup bottle, trying to get the last bit out.      intransitive verb         to squint, pucker, or contort   to crouch down or draw oneself together so as to seem smaller; ;  (Source: .)   to flinch         Word Origin: probably blend of squint and pinch      First Known Use: 1835      Example Sentences Including "squinch:"      Cooper saw her squinch up her eyes, trying to make out who was standing outside her kitchen window.      An unhappy smile is still a smile, insofar as the corners of the mouth are drawn back or upturned. However, the eyebrows may be furrowed, and the eyes may be squinched or teary. Also, the lips tend to be pressed together, rather than relaxed as in a happy smile.    My question is, how do native speakers of AmEng use the verb squinch in the senses supported above by CAED?  In addition, what's the difference between using either "squinch" or "squint/flinch" as in the following examples:     She squinched (up) her eyes, trying to make out who was standing outside.      She squinted her eyes, trying to make out who was standing outside.   -and-     The driver squinched as the sun hit his windshield.         -and-              -and-     He squinched as the cold water struck him.         -and- How to set up a wi-fi hotspot with an Ubuntu laptop (access point mode)? I've read , and carefully followed the instructions provided. I am sure the wireless card in my laptop supports going into wireless access point mode. But unfortunately, when I use the following command to start hostapd service it throws an error:   $ sudo service hostapd stop  Starting advanced IEEE 802.11 management hostapd                      [fail]    The instructions mentioned above said this could possibly be because my wireless card does not support the g mode, and provided the wiki of hostapd. But what is g mode? I tried to switch to a, or b mode, but it just didn't work.  Can anyone help with this or recommend a tool like connectify in windows ?  ps. I am using Ubuntu 12.04, 32 bit. I have an ADSL wired network, and I want to share it by setting my laptop into a WiFi hotspot with  my windows phone. What software works well for viewing massive TIFF images on Windows 7? How to read "service --status-all" results I need to identify the currently running services but I can't figure out the results of running service --status-all, I mean what does ?, - and + mean ?  $ service --status-all  [ + ]  acpid  [ + ]  anacron  [ + ]  apparmor  [ ? ]  apport  [ ? ]  atieventsd  [ + ]  avahi-daemon  [ ? ]  binfmt-support  [ + ]  bluetooth  [ - ]  brltty  [ + ]  console-font  [ + ]  console-setup  [ + ]  cron  [ + ]  cups  [ + ]  cups-browsed  [ - ]  dbus  [ ? ]  dns-clean  [ + ]  friendly-recovery  [ - ]  grub-common  [ ? ]  irqbalance  [ - ]  kerneloops  [ ? ]  killprocs  [ + ]  kmod  [ ? ]  lightdm  [ - ]  lm-sensors  [ ? ]  mysql  [ ? ]  networking  [ ? ]  ondemand  [ ? ]  pppd-dns  [ - ]  procps  [ - ]  pulseaudio  [ ? ]  rc.local  [ + ]  resolvconf  [ + ]  rfkill-restore  [ + ]  rfkill-store  [ - ]  rsync  [ + ]  rsyslog  [ + ]  saned  [ ? ]  sendsigs  [ + ]  setvtrgb  [ ? ]  speech-dispatcher  [ - ]  sudo  [ + ]  timidity  [ + ]  udev  [ ? ]  umountfs  [ ? ]  umountnfs.sh  [ ? ]  umountroot  [ - ]  unattended-upgrades  [ - ]  urandom  [ + ]  virtualbox  [ - ]  x11-common   And would running this command with sudo make any difference ? I tried it and in my case it didn't make any difference, but may it differ in other setups ? I had to write the proof to show that an Ideal $P$ of a commutative ring $R$ is prime Ideal if $R/P$ is an integral domain.       let $a,b\in R$ s.t. $ab\in P$ ,        $$ab+P=P\implies(a+P)(b+P)=P\implies\overline a \overline b=0$$  and as $R/P$ is an integral domain either $a=0$ or $b=0$ $\implies a+P=P$ or  $b+P=P$.        $\therefore$ either $a\in P$ or $b\in P$.   Hence, $P$ is a prime Ideal.    Am I correct in writing this or am I making some error... Why do soap operas have the soap opera effect? The soap opera effect occurs when frame interpolation is used. For example, if a movie is shot at 24 frames per second and then shown on a TV screen which is capable of displaying 60 frames per second then it is possible to use a computer to do motion interpolation. In other words the computer can average (interpolate) two frames and create a synthetic third frame and stick it between the two real frames.  This interpolation makes the picture look unnatural and plastic, somewhat like soap operas look on TV, hence the name.  My understanding of why soap operas have the soap opera effect has something to do with the fact that many of them are shot using camcorders instead of film, but I am not completely sure.  Why do soap operas have the soap opera effect? What visa does my wife need to travel to the UK with me, if I'm going there on a business visa? I am resident of India and just got UK Business visa ( 6 months, multiple entry) .. I am going for a week on business trip. I want to take my wife along with me and at the end of trip.. I want to extend my trip for 3 days and we want to spend some time on leisure.   What visa I should apply for my wife.. visitor visa? should she mention in the visa form that she is going along with me and staying with me while I am on work and later we are spending time on leisure.   While filling my business visa form, there was a field asking if anyone else is going with me.. I selected no.. as there were no plans.  Also is it ok to spend time on leisure on UK Business visa He who must not be named? (aka Anyone can ping everyone in chat) For some or other reason, typing @ᔕᖺᘎᕊ in a chat room pings everyone who's been in that chat room for the last 7 days...    Seems to work in all chat rooms (I only tested 2 as I don't want to upset too many people...)  How should we proceed? Reviewed suggested edit view for title-only edits takes body of last revision? Yesterday I was pointed at some rejected suggested edits. Some of the corrections were valid, so I edited the posts accordingly, while making several further edits. Looking at the suggested edits now however, it seems that for those posts where only changes to the title were originally suggested, the post mortem suggested edit view now incorporates the body of the latest revision. (Or at least it appears like that to me)  Take for example . If you take a look at  of that post, you will see my later edits. The edited body seems to have been incorporated in the suggested edit view. For edits where originally changes to the body were suggested, there is no such confusion.   Why does this matter? In the case of some post mortem discussions or explanations it might help to see the actual situation as it was when the edit was suggested. Especially in the case of edits that might be considered too minor.   So have I stumbled upon a bug here? Batch convert 4 PDF pages to one PDF page How do I set the grub timeout and the grub default boot entry? In Ubuntu 12.04 (or above), how do I set the GRUB time and the default OS (that I see at boot time) as I'm dual-booting Windows (7/8) and Ubuntu (12.04 or above)? A cashier wants to work five days a week, but he wants to have at least one of the Saturday and Sunday off.  In how many ways can he choose the days he will work?  So, in this case, what should I count first?  How do I start?  I know how to solve this if the cashier doesn't want a weekend off, but what do I do if the cashier do?  Thanks! How can I bake the cloth simulation into keyframed vertices or shape keyed vertices? I'm simulating a cloth. How can I bake the cloth simulation into keyframed vertices or shape keyed vertices? Proving that $d(f,g)=\|f-g\| = \sup \limits_{0\leq x \leq 1} |f(x)-g(x)|$ is a metric on $X=C[0,1]$ Let $X=C[0,1]$ be the set of all continuous functions on $[0,1]$. For any two functions $f,g\in X$, set $$d(f,g)=\|f-g\| = \sup \limits_{0\leq x \leq 1} |f(x)-g(x)|.$$  Prove $(X,d)$ is a metric space.    My attempt:  This question comes down to showing that $d$ is a metric, which means that:   $d(f,g)\geq 0$ $d(f,g)=0\iff f=g$ $d(f,g)=d(g,f)$ Triangular sadness.     1) Nonnegativity is guaranteed by taking the supremum of the absolute value of a sum, since the absolute value of a sum is non-negative, the supremum of non-negative numbers is non-negative.  $\square$    2) For the supremum of $|f(x)-g(x)|$ to be equal to $0$, the greatest number for $|f(x)-g(x)|$ from $0\leq x\leq 1$ must be $0$, hence $|f(x)-g(x)|=0$ for all values on this range, and thus $f(x)=g(x)$ is the constant zero map.  $\square$    3) $|f(x)-g(x)|=|g(x)-f(x)|$ implies that $\sup \limits_{0\leq x \leq 1} |f(x)-g(x)|=\sup \limits_{0\leq x \leq 1} |g(x)-f(x)|$ $\square$    4) Triangular sadness:  We need to prove that $d(f,g)\leq d(f,h) + d(g,h)$  I.e.  $\sup \limits_{0\leq x \leq 1} |f(x)-g(x)|\leq \sup \limits_{0\leq x \leq 1} |f(x)-h(x)|+\sup \limits_{0\leq x \leq 1} |g(x)-h(x)|$  Now I am not sure how I can 'behave' with the sup 'function'. Can I do the following?  $$\sup|f(x)-g(x)| = \sup|f(x)-g(x)+h(x)-h(x)|=\sup|f(x)-h(x)+(h(x)-g(x))|$$ Then use normal triangular inequality:  $$\sup|f(x)-h(x)+(h(x)-g(x))|\leq \sup(|f(x)-h(x)|+|h(x)-g(x)|)=\sup(|f(x)-h(x)|+|g(x)-h(x)|)$$   This is obviously less than $\sup \limits_{0\leq x \leq 1} |f(x)-h(x)|+\sup \limits_{0\leq x \leq 1} |g(x)-h(x)|$, but I don't know how to prove it. How do I finish that one off. $n &gt; 2$ and $n$ is a prime number then $n$ is odd.  Prove by contradiction assume $n$ is even then there is some $k\in\Bbb N, n = 2k$ then $n &gt;2, 2k &gt; 2 , k &gt; 1$  Is this  a sufficient proof? all the LaTeX-tutorials tell me how LaTeX is an extention simplifying the building of TeX documents. Understandably, no one uses plain TeX anymore, right?  But I seem to learn better when I grasp the link between TeX and LaTeX. Does someone have a link to example files in plain TeX? I'd like to know which commands, macros etc. are LaTeX-specific. How to delete a keyboard layout in Windows 10 I installed Windows 10 on a physically German keyboard, then installed a Window English software keyboard and bought some little stickers to make my keyboard look OK.  However, Windows shows 2 keyboards installed &amp; occasionally toggles back to German.  Note that I am not talking about removing a language (which is all that I can find when I Google).  How do I remove the German keyboard layout? How do "Dummy Variables" work? I do not understand how dummy variables work in math.   Suppose we have:  $$I_1 = \int_{0}^{\infty} e^{-x^2} dx$$  How is this equivalent to:  $$I_2 = \int_{0}^{\infty} e^{-y^2} dy$$  How does this dummy variable system work?   Since $y$ is the dependent variable for $I_1$ How can $y$ itself be and independent variable for $I_2$  ??  Thanks!