reverse clip (erase) for spatial point data frame (R)
In ArcGIS there is a Erase Point tool how can this be done in R
How can I randomize order of elements in a list? Configure HAProxy to include host headers for different backends I am exploring the use of HAProxy as a balancer in front of a set of web apis that run on IIS.   node1.myapp.mycompany.com node2.myapp.mycomapny.com   We are currently using Host Headers to correctly resolve the right web application on IIS.  For example, we may have otherapp.mycompany.com running on the same server/port, but using Host Headers IIS knows which one to serve up.  My initial attempt at HAProxy left me with 404 errors, because I was not including the host headers in my request, and so IIS was serving back the default site bound to the given IP, and not resolving by host name.    The fix left me with something like this:  frontend localnodes     bind *:80     mode http     default_backend nodes  backend nodes     mode http     balance roundrobin     option forwardfor     reqirep ^Host: Host:\ node1.myapp.mycompany.com     server web01 node1.myapp.mycompany.com:80   This works great for a single backend, but I am left scracthing my head on how to include the correct host headers depending on which backend is serving up the request:  backend nodes     mode http     balance roundrobin     option forwardfor     reqirep ^Host: Host:\ node1.myapp.mycompany.com     server web01 node1.myapp.mycompany.com:80     server web02 node2.myapp.mycompany.com:80   The above does not work whenever node2 is used because it doesn't resolve correctly in IIS (node2 in this case is on a different server, and therefore different IP.  In fact, if they were running on the same server/ip I suspect the request work "work", but they would all be served by node1 per the host header).     Is it possible to set the host based on the url of the backend used to serve up the request? If so, this implies my checks also need to provide the correct host header based on backend, how would that be done?   Edit: Am using HA-Proxy version 1.7.9 2017/08/18  Let me give this just a little more background.  We used to have just myapp.mycompany.com serving up api requests.  We need to expand it.  Our clients will still call myapp.mycompany.com, but that will just point to the HAProxy, which will balance it out to node1.myapp.mycompany.com and node2.myapp.mycompany.com.  Our current server configurations have us binding a single IP address on each server, so we use host headers to resolve. Truncated 200GB table but disk space not released I have only 2GB left, so I need to remove this history table. This table now is empty but the database disk space not released. And the database file is 320GB. Let $X$ be a set and consider the collection $\mathcal{A}(X)$ of countable or cocountable subsets of $X$, that is, $E \in \mathcal{A}(X)$ if $E$ is countable or $X-E$ is countable. If $X$ is countable, then $\mathcal{A}(X)$ coincides with the power set $\mathcal{P}(X)$ of $X$. Now suppose that $X$ is uncountable. Assuming the axiom of choice, we can conclude that $\mathcal{A}(X) \ne \mathcal{P}(X)$, since $|X| = |X| + |X|$. So the question is:     Can we prove in ZF that $\mathcal{A}(X) \ne \mathcal{P}(X)$ for every uncountable set $X$?   I'm assuming that a set $X$ is uncountable if there is no injective function $f : X \rightarrow \mathbb{N}$. Whenever I try to do a fluid simulation, the fluid domain remains visible.  I have tried:ctrl+a-scale, turn on/off visibility for render/viewport  Here's a video demonstrating my problem:   Here's the blend file in case I have messed up some settings:   Thank you for any help! I remember reading this book in the late 80's or early 90's. It was a - sort of - semi SciFi contemporary fairy tale.  It was set in Manhattan in contemporary times, near future and (I think) late 1800's. There was a mist wall round New York that ships could disappear into and arrive out at different times.  There was a man with a white horse, the horse could fly but had forgotten how. The man is brought forward from the past but (like the horse) forgets who he is.  An engineer arrives from the future in a gigantic ocean liner and builds a bridge of light to heaven (possibly at the last millennium turn over).   It was a very involved book with a huge cast of characters that all had some part to play in the story.  In the 1800's story there was a girl suffering from consumption, she slept in a glass room on the roof of her house, open to the freezing winter air, it was what kept her alive. She was rich (the family had made money in whaling) but somehow she and The Man (the guy with the white horse, who was pretty much a nobody) met and fell in love (I think).  Some of the story was set around a lake in upstate NY, and one character started off in San Francisco (contemporary times) and traveled to the lake.  Anyone any idea what I'm talking about? Can it hurt to put my GRE score on my resume? is $y = \sqrt{x^2 + 1}− x$ a injective (one-to-one) function? I have a function  $y = \sqrt{x^2 + 1}− x$ and I need to prove if it's a Injective function (one-to-one).  The function f is injective if and only if for all a and b in A, if f(a) = f(b), then a = b  $\sqrt{a^2 + 1} − a = \sqrt{b^2 + 1} − b$  $\sqrt{a^2 + 1} + b = \sqrt{b^2 + 1} + a$  $(\sqrt{a^2 + 1} + b)^2 = (\sqrt{b^2 + 1} + a)^2$  $a^2 + 1 + b^2 + 2b\sqrt{a^2 + 1} = b^2 + 1 + a^2 + 2a\sqrt{b^2 + 1}$  $2b\sqrt{a^2 + 1} = 2a\sqrt{b^2 + 1}$  $b\sqrt{a^2 + 1} = a\sqrt{b^2 + 1}$  $(b\sqrt{a^2 + 1})^2 = (a\sqrt{b^2 + 1})^2$  $b^2(a^2 + 1) = a^2(b^2 + 1)$  $b^2a^2 + b^2 = a^2b^2 + a^2$  $b^2 = a^2$  $\sqrt{b^2} = \sqrt{a^2}$  $b = \pm a$  then the function is not injective because $b$ in not equal to $a$, but using online  the function is injective. Coupon Collector Problem with Batched Selections Is it correct? It's the message I see right before the metro/subway train shows up.  Shouldn't it be "train is approaching" or "train approaches"? Let $f$ and $g$ be entire functions such that $f^n+g^n=1$, where $n\geq 3$ is an integer. Prove that $f$ and $g$ are constant.  I suppose I should somehow prove that either $f$ or $g$ is bounded so that I can apply Liouville's Theorem, but I don't see how. I tried setting the derivative of the left hand side equal to zero and work with that but that did not seem to work. How many of Trelawney's prophecies have come true? onChange event doesn't trigger Is it possible to recover original content from an edited image file? OK possibly a random question here, but one that is relevant to the site and regarding a hot topic nowadays: privacy.  If I load an image file (in my case a PNG photocopy of a document which contains some personal details) into Gimp, and I 'fill' with black (i.e. as if to redact) the areas of the image that contain sensitive information, and I then overwrite the original file, is there any way that the original untouched image can be recovered or gleamed? Such as low level bit analysis or...?  If so what tools and techniques are behind that, and how can I mitigate this? Is it a simple case of not overwriting the original but simply creating a new file with the changes? Minimum of $\sqrt{\frac{a}{b+c}}+\sqrt{\frac{b}{c+a}}+\sqrt{\frac{c}{a+b}}$ What is the minimum of $$f(a,b,c):=\sqrt{\dfrac{a}{b+c}}+\sqrt{\dfrac{b}{c+a}}+\sqrt{\dfrac{c}{a+b}}$$ where $a,b,c$ are positive real numbers?  When $a=b=c$, we have $f(a,b,c)=\dfrac{3}{\sqrt{2}}\approx 2.12$  When $a=1,b=c\rightarrow\infty$, we have $f(a,b,c)\rightarrow 2$. So the minimum is at most $2$. What are the current travel restrictions on individuals entering the United States from regions affected by Covid-19? This community wiki explains the current restrictions by the United States of America on the entry of individuals who may pose a risk of transmission of the SARS-Cov2, the virus which causes the Covid-19 disease. I've been studying the Huddleston and Pullum book for four months now. So far only one thing confuses me: the identity of gerund. Is it a noun or a verb?        His constant smoking upset me.  smoking seems  noun because of adjective constant.   Him/His constantly smoking upset me. smoking seems to be verb because of adverb constantly.   Him/His smoking cigars upset me. smoking seems to be a verb because of object cigars.      "His smoking upset me." So is this smoking gerund a noun or verb? Because there is no differentiation, is it both verb and noun? Maybe it's new word category?  Also his seems to be both  sometimes a subject and at other times a possessive determiner. Is that correct? ffmpeg synchonization of libfdk_aac (or libfacc) and libx264 How to synchronize libfdk_aac and libx264 streams?  ffmpeg -i pipe_libfdk_aac.fifo -i pipe_libx264.fifo -c copy -f flv flv_stream_pipe_or_rtmp.output   I'm always receiving the same asych in all cases: saving file on file system, rtmp-using or raw pipe out. Is it possible to syncronize them?   ffmpeg version N-66924-gaba61b2 Copyright (c) 2000-2014 the FFmpeg developers built on Jan 15 2015 12:50:29 with gcc 4.6 (GCC) 20120106 (prerelease) configuration: --arch=arm --cpu=cortex-a8 --target-os=linux --enable-runtime-cpudetect --prefix=/data/data/info.guardianproject.ffmpeg/app_opt --enable-pic --disable-shared --enable-static --cross-prefix=/home/qwerty/work/android-ndk-r10b86/android-ndk-r10b/toolchains/arm-linux-androideabi-4.6/prebuilt/linux-x86/bin/arm-linux-androideabi- --sysroot=/home/qwerty/work/android-ndk-r10b86/android-ndk-r10b/platforms/android-3/arch-arm --extra-cflags='-I/home/qwerty/x264 -I/home/qwerty/ffmpeg_build/mp3/build/include -I/home/qwerty/faac/output/include -I/home/qwerty/ffmpeg_sources/fdk-aac/build/include -I/usr/local/include/ -mfloat-abi=softfp -mfpu=neon' --extra-ldflags='-L/home/qwerty/x264 -L/home/qwerty/ffmpeg_build/mp3/build/lib -L/home/qwerty/ffmpeg_sources/fdk-aac/build/lib -L/home/qwerty/faac/output/lib -L/usr/local/lib/ -lrtmp -lpolarssl' --enable-version3 --enable-gpl --enable-nonfree --disable-doc --enable-yasm --enable-decoders --enable-encoders --enable-muxers --enable-demuxers --enable-parsers --enable-protocols --enable-filters --enable-avresample --enable-librtmp --enable-libfaac --enable-libfdk_aac --enable-libmp3lame --disable-indevs --enable-indev=lavfi --disable-outdevs --enable-hwaccels --enable-ffmpeg --disable-ffplay --disable-ffprobe --disable-ffserver --disable-network --enable-libx264 --enable-zlib --enable-muxer=md5 libavutil      54. 10.100 / 54. 10.100 libavcodec     56.  8.100 / 56.  8.100 libavformat    56.  9.100 / 56.  9.100 libavdevice    56.  1.100 / 56.  1.100 libavfilter     5.  1.106 /  5.  1.106 libavresample   2.  1.  0 /  2.  1.  0 libswscale      3.  1.101 /  3.  1.101 libswresample   1.  1.100 /  1.  1.100 libpostproc    53.  3.100 / 53.  3.100 Proving that $\frac{1}{1\cdot 2} + \frac{1}{2\cdot 3} + \frac{1}{3 \cdot 4} +\ldots + \frac{1}{n(n+1)} = \frac{n}{n+1}$ How would we go about proving that $$\frac{1}{1\cdot 2} + \frac{1}{2\cdot 3} + \frac{1}{3 \cdot 4} +\ldots +\frac{1}{n(n+1)} = \frac{n}{n+1}$$ Select translation: where?