投稿時間:2021-07-24 11:16:53 RSSフィード2021-07-24 11:00 分まとめ(22件)

カテゴリー等	サイト名等	記事タイトル・トレンドワード等	リンクURL	頻出ワード・要約等/検索ボリューム	登録日
TECH	Engadget Japanese	身軽さとお洒落を両立。エイジングも愉しめる「本革ショルダー」	https://japanese.engadget.com/leather-shoulder-bag-021427878.html		2021-07-24 01:15:27
ROBOT	ロボスタ	NVIDIAが対話型AIをスマートでインタラクティブにする「TensorRT 8」を発表　BERTで世界最速級のAI推論性能	https://robotstart.info/2021/07/24/nvidia-tensor-rt8.html	nvidia	2021-07-24 01:00:47
python	Pythonタグが付けられた新着投稿 - Qiita	「天気図っぽい」気象前線の自動描画を日本から世界に拡張してみる〜領域拡張と地図投影	https://qiita.com/m-taque/items/b4ea490667d88cd10a55	「天気図っぽい」気象前線の自動描画を日本から世界に拡張してみる領域拡張と地図投影天気図っぽい気象前線の自動描画を日本から世界に拡張してみる領域拡張と地図投影目次はじめに日本付近の気象データから「天気図っぽい」前線を自動描画する機械学習学習したネットワーク・パラメタを他の地域の気象データに適用する機械学習と地図ステレオ投影された前線画像から正投影地図への座標変換地図pcolormeshを用いての画像の貼り付け地図と可視化まとめはじめに以前に数値気象予報モデルのデータから、気象庁が解析した「気象前線」を、機械学習ニューラルネットワークを用いて自動的に描画する、というプログラムを作成したことがありました。	2021-07-24 10:51:38
python	Pythonタグが付けられた新着投稿 - Qiita	【Python】for文を用いた要素の取り出しとカウント　enumerate関数	https://qiita.com/naokinaoki230/items/1924dc674b2a92ff8e20	【Python】for文を用いた要素の取り出しとカウントenumerate関数リストからの要素の取り出しfor文を使うことで簡単にリストから要素を取り出すことができる。	2021-07-24 10:41:21
python	Pythonタグが付けられた新着投稿 - Qiita	SMTソルバー Z3Py	https://qiita.com/Ganesha/items/7a606ffc8a7c2504c143	SMTソルバーZPyちょっと前に「AnswerSetProgramming」というのが使えそうだと思ったのだが、記述表現がよくわからなく停滞していたが、同じようなことをが「ZPy」を使うとPythonで書けるということで、例題を通じて理解を深めようと思う。	2021-07-24 10:39:42
Program	[全てのタグ]の新着質問一覧｜teratail（テラテイル）	シェルのhistoryを切り替えたい	https://teratail.com/questions/350971?rss=all	history	2021-07-24 10:57:23
Program	[全てのタグ]の新着質問一覧｜teratail（テラテイル）	一行にまとめる方法について	https://teratail.com/questions/350970?rss=all	一行にまとめる方法についてdeffifthcharfilenamedatawithopenfilenamerasffortextinfreadlinesiflentextgtdatatextdatareplacenfclosereturndataファイル内にたくさんの文字列が入っているとき、すべての文字列の五番目の文字を一行にまとめて抜き出したいです。	2021-07-24 10:46:28
Program	[全てのタグ]の新着質問一覧｜teratail（テラテイル）	Macのターミナルでpwdで表示されるパスとコマンドを実行するときのパスが異なる	https://teratail.com/questions/350969?rss=all	dockercomposenbspbuild	2021-07-24 10:31:48
Program	[全てのタグ]の新着質問一覧｜teratail（テラテイル）	他ディレクトリからのincludeがうまくできない	https://teratail.com/questions/350968?rss=all		2021-07-24 10:30:46
Program	[全てのタグ]の新着質問一覧｜teratail（テラテイル）	ウェブサービスにおけるユーザー登録の実装方法	https://teratail.com/questions/350967?rss=all	ウェブサービスにおけるユーザー登録の実装方法ウェブサービスの作成にあたり、ユーザー登録の実装方法で質問があります。	2021-07-24 10:30:45
Program	[全てのタグ]の新着質問一覧｜teratail（テラテイル）	herokuでS3に画像を保存したい	https://teratail.com/questions/350966?rss=all	herokuでSに画像を保存したい前提・実現したいことlaravelで投稿アプリを作成しています。	2021-07-24 10:11:22
Program	[全てのタグ]の新着質問一覧｜teratail（テラテイル）	双方で必須の外部キーを持っているときのFactoryBotの書き方について	https://teratail.com/questions/350965?rss=all	双方で必須の外部キーを持っているときのFactoryBotの書き方についてUserモデルにaffiliationidが必須。	2021-07-24 10:02:39
Program	[全てのタグ]の新着質問一覧｜teratail（テラテイル）	PHP レンタルサーバーでGDのfontを変更する事は不可能ですか？	https://teratail.com/questions/350964?rss=all		2021-07-24 10:02:36
海外TECH	DEV Community	C++ is awesome, here's why...	https://dev.to/vinitjogani/c-is-awesome-here-s-why-1be0	C is awesome here x s why C is hands down one of the most misunderstood languages in software developer pop culture today People often compare it to C because it is a low level language Consequently it has received a reputation of being an esoteric language that only the performance paranoid care about This is far from true I have been programming in C as my primary language for a while now and the developer experience is actually really good much better than I had imagined it would be In this article I want to debunk some common myths about C that I heard before I started using it Then I want to talk about the actual superpowers that C provides you that most other languages do not Myth memory this memory thatWe all know that C is infamous for manual memory management e g with the malloc and free They are hard to work with lead to many error conditions that need to manually be checked for and is overall a nightmare When people hear that C also has great performance people assume that it is by dabbling into all the specifics of memory allocation much like in C so they conclude that it would also be a nightmare This is categorically false For a while now C has had smart pointers Using these you can get the same behavior as you get with objects in other languages like Java and Python In particular the std shared ptr works by wrapping a regular object in a copy able and movable object with a reference counting mechanism Thus when no code is referencing a shared ptr it is safely destructed and freed like in most languages The simplest way to construct a shared pointer is as follows std shared ptr cat new Pet cat orstd shared ptr cat std make shared lt Pet gt cat While this is the common pattern in most other languages C allows you to have further control on how an object is accessed e g using a unique ptr but more on that later Overall with smart pointers managing memory in C is no harder than any other languages It is however intentional in that you need to clarify that this is your expected behavior because you can still create and pass around regular pointers the good ugly old way Typically with good use of these you are also very unlikely to run into segmentation faults which were oh so common in C Myth it is old and outdatedC is very actively maintained with new features that continue to be rolled out at a regular basis I think one of the most common new features in many languages that people have grown to admire is lambdas Surely C doesn t have lambdas right Wrong A C lambda function can be defined as auto square int x return x x For context Java got lambdas in with the release of Java C has had lambdas since C Yep And there continue to be major updates e g C most recently that introduce even more features to make C easier to work with For example variable length arguments have been in C for a while with variadic templates Generics work great in C as well although differently from what you may be used to in Java These features continue to improve the way we develop software Myth it is easy to get wrongOn the contrary while learning some of its quirks may take a while C makes it very hard for your code to do undesired things For example many object oriented languages do not have support for pure functions i e functions that are guaranteed to be immutable In C you can actually mark methods of a class as const if they don t modify the class state These methods can then also be called on constant instances of the class Here s an example class Greeting public Greeting std string greeting greeting greeting std string get greeting const return greeting std string set greeting std string new greeting new private std string greeting Now you can initialize this class as a constant and still call the getter If you try to mutate the state of the class the compiler will complain const Greeting g hello g get greeting returns hello g set greeting hi does not compileTo be accurate these functions are not fully pure in that if you don t type some of your variables correctly it is possible to mutate the resources For example if you have a const pointer to a non const object you may not modify the pointer but can modify the object pointed to by the pointer However these problems can typically be avoided by typing the pointer correctly i e making it a const pointer to a const object It may seem like I am self contradicting here by mentioning such an edge case in a common use case However I don t think it really contradicts what my larger claim here is C makes it hard to go wrong assuming you know what you want by giving you the tools to express exactly that in code While programming languages like Python might abstract it all away from you they come at a much higher cost Imagine going into an ice cream shop and only having chocolate served to you because that s what most people generally want that s Python Depending on how you look at it sure in some sense it is harder to go wrong with chocolate in general it is not upto the shop but the user to know what they need Good const ness is a big plus but there s several other things that C allow you to do that prevent production bugs from occurring in larger projects It allows you to configure move copy delete semantics for the classes you design if you need It allows you to pass things by value and advanced features like multiple inheritance All these things make C less restrictive Myth it is verboseOkay this is not completely inaccurate Coming from Python where folks are so tired of typing numpy that they just collectively all decided to import it as np typing more than letters does feel verbose But modern C is a lot less verbose than it used to be For example type inference like Go is available in C with the introduction of the auto keyword auto x x worksx abc compilation errorYou can also use auto in return types auto func int x return x x You can also use it in for loops to loop over maps for example for auto amp key value hashmap auto does not mean that the types are dynamic they are still inferred at compile time and once assigned they cannot be changed This is probably for the best In practice for large codebases it arguably also helps readability to specifically type out the full type instead of using auto However the feature is there if you need it You can also specify type and or namespace aliases like in Python For example you can do something like using tf tensorflow Now you can use tf Example instead of tensorflow Example C templates similar to Java Generics but pretty different at the same time can also help significantly cut down duplicate code and may be an elegant solution for many use cases Overall C is definitely more verbose than many new programming languages like Kotlin and Python However it is not a lot more verbose than C or Java or even JavaScript to some extent and the verbosity of those languages has not affected their popularity too much Myth hard to do common thingsAgain this is not completely inaccurate Common operations like joining strings by a delimiter are more complicated than they need to be However this is a problem solved rather easily with open source libraries like Google s Abseil with thousands of utility functions that make it very easy to work with Apart from string utilities Abseil also contains special implementations of hashmaps concurrency helpers and debugging tools Other libraries like Boost make it easy to work with BLAS routines e g dot products matrix multiplications etc and are very performant Using libraries itself can be a challenging task in C with having to maintain CMake files although in many ways those are not much different from the gradle or package json files in other languages However again Google s open source build tool Bazel makes it extremely easy to work with even with cross language builds It takes some getting used to but provides really quick builds and in general has a very good developer experience SuperpowersSo after busting all those common myths about C here are some things in C that a lot of other languages don t allow you to do Customize semantics of your classesSuppose you have a class that contains some large data You would prefer it not be copied and instead be passed by reference always You can enforce this as a designer of the interface Moreover you can configure exactly how you would like it to be copied if at all it is required What about moving objects instead of copying all data from the previous block of memory to a new block and then deleting the old block of memory maybe you can optimize it by just switching the pointer locations What about destroying objects when a object goes out of scope maybe you automatically want to release some resources e g think mutexes that are automatically released at the end of the function This works much like the defer functionality in Go As a designer of an interface you can customize every small aspect of how users will use your class In most cases this is not necessary but when it is C allows you to fully express your requirements That is very powerful and can save your company hours of time on large projects Optimize memory accessI briefly mentioned smart pointers above Apart from shared ptr you can also have a unique ptr that ensures that only one object can own a resource Having one owner for data makes it easy to organize and reason about large projects In fact while shared ptr most closely mimics Java and other OOP languages you re generally better off using a unique ptr This also adds to the safety of the language You can also specify compile time constants to enable the compiler to do more work during the build so that the binary runs faster overall Strong typesIn general I have found that working with typed objects is SO much easier to debug than other languages For example after hours of debugging a JavaScript project I found that the error arose because I was passing in argument to a argument function JavaScript threw no errors and just produced undesired outputs I would much rather have something fail to compile than fail during runtime However there are many typed languages out there so it may seem overkill to use this as a super power But C does more First of all C lets you pass anything by reference by pointer or by value That means you can pass in a reference to an integer and have a function mutate it instead of using the return value might be handy in some cases It also means that you can perform memory level operations using a pointer on anything if need be Usually though you would like to pass things as a constant reference e g const A amp which does not lead to a copy and keeps your object safe from being mutated unintentionally Those are strong guarantees to have and that makes your code just so much easier to reason about In typescript for example you cannot reassign a const object but you can mutate it Why even just uggh CaveatsSo C is great and all but there are obvious limitations to what I would use it for You can write microservices e g in gRPC rather easily but I would likely not use C for the actual web server I would likely use TypeScript for that Despite its speed I would likely not use C for data analysis I would likely use pandas for that There are some things that C is great for and there are other things that it s just not suitable for Ultimately you still have to choose the right tool for whatever job you re trying to accomplish Having said that hopefully this article made C a bit more attractive in your eyes than you re used to seeing it as	2021-07-24 01:18:30
海外TECH	DEV Community	Separation of concerns: Templates, Component	https://dev.to/takuyakikuchi/separation-of-concerns-templates-component-5h3p	Separation of concerns Templates ComponentPete Hunt React Rethinking best practices JSConf EU YouTube What is Separation of concerns the idea that each module or layer in an application should only be responsible for one thingReduce coupling Increase cohesioncoupling each modules relies on each of the other modules cascading changescohesion elements of a module belong together TemplatesTemplates encourage a poor separation of concerns View model tightly couples templates to display logicdisplay logic and markup are inevitably tightly coupleddisplay logic and markup are highly cohesiveTemplates separate technologies not concerns React ComponentA highly cohesive building block for UIs loosely coupled with other componentscomposable Take awaysSeparation of concerns Separate technologies	2021-07-24 01:09:14
海外科学	NYT > Science	Olympics Covid Cases Raise Tricky Questions About Testing	https://www.nytimes.com/2021/07/21/health/coronavirus-olympics-testing.html	infections	2021-07-24 01:45:54
海外科学	NYT > Science	'No One is Safe': How the Heat Wave Has Battered the Wealthy World	https://www.nytimes.com/2021/07/17/climate/heatwave-weather-hot.html	x No One is Safe x How the Heat Wave Has Battered the Wealthy WorldFloods swept Germany fires ravaged the American West and another heat wave loomed driving home the reality that the world s richest nations remain unprepared for the intensifying consequences of climate change	2021-07-24 01:01:16
ニュース	BBC News - Home	Covid-19: More testing sites for key workers to avoid isolation in England	https://www.bbc.co.uk/news/uk-57950930	contact	2021-07-24 01:14:07
ニュース	BBC News - Home	Helen Glover and Polly Swann: Team GB pair third in Tokyo Olympics heat	https://www.bbc.co.uk/sport/av/olympics/57950901	Helen Glover and Polly Swann Team GB pair third in Tokyo Olympics heatOlympic champion Helen Glover and partner Polly Swann finish a disappointing third in their women s pair heat on day one of the Tokyo Olympics but reach the semi finals	2021-07-24 01:50:58
北海道	北海道新聞	五輪サッカー男子２５日に第２戦　メキシコ戦、２連勝で突破決定も	https://www.hokkaido-np.co.jp/article/570356/	連勝	2021-07-24 10:12:19
北海道	北海道新聞	中国・台山原発、仏なら一時停止　燃料棒破損、合弁の電力会社見解	https://www.hokkaido-np.co.jp/article/570376/	一時停止	2021-07-24 10:08:08
北海道	北海道新聞	混合ダブルス渡辺・東野組が初戦　バドミントン・２４日	https://www.hokkaido-np.co.jp/article/570507/	混合ダブルス	2021-07-24 10:01:00