named

How to use `assign()` or `get()` on specific named column of a dataframe?

由 荒凉一梦 提交于 2019-12-18 03:44:44
问题 Is there a way to assign a value to a specific column within a data frame? e.g., dat2 = data.frame(c1 = 101:149, VAR1 = 151:200) j = "dat2[,"VAR1"]" ## or, j = "dat2[,2]" assign(j,1:50) The approach above doesn't work. Neither does this: j = "dat2" assign(get(j)[,"VAR1"],1:50) 回答1: lets assume that we have a valid data.frame with 50 rows in each dat2 <- data.frame(c1 = 1:50, VAR1 = 51:100) 1 . Don't use assign and get if you can avoid it. "dat2[,"VAR1"]" is not valid in R . You can also note

Microsoft Z3 naming assertions

由 泪湿孤枕 提交于 2019-12-13 12:37:53
问题 I need to name some assertions im my z3 model so that it is able to generate unsat cores. I can do this manually like this: (assert (! (assertion) :named x)) I just need to do it using the .NET API directly. any help? 回答1: Z3 does not support this directly through the .NET API. Instead, a Boolean constant should be created (the name, e.g., x ), which can then be used to assert conditional constraints, e.g., solver.AssertAndTrack(constraint, x); The constraint is then named x and this constant

关于 python ImportError: No module named 的问题

由 一个人想着一个人 提交于 2019-12-12 20:26:48
【推荐】2019 Java 开发者跳槽指南.pdf(吐血整理) >>> 今天在 centos 下安装 python setup.py install 时报错：ImportError: No module named sysconfig， 当时急着用，就顺手直接源码编译了一把，make install 后就 ok 了。 然后又在 cygwin 下安装时同样的问题，这下 cygwin 源码编译也不行了，因为会调用很多 linux 特有的类库。 虽然最后解决了 import 的问题，但是又报了其它错。比如 ldconfig 啥的，可能是我cygwin环境没装全。 只有换方法：从cygwin开源镜像上下载好 cygwin binary 版本的 python 2.7.3， 然后覆盖到相应的目录即可。 事后我查了下 python 的import机制，以备忘： python中，每个py文件被称之为模块，每个具有__init__.py文件的目录被称为包。只要模块或者包所在的目录在sys.path中，就可以使用import 模块或import 包来使用。 如果想使用非当前模块中的代码，需要使用Import，这个大家都知道。 如果你要使用的模块（py文件）和当前模块在 同一目录 ，只要import相应的文件名就好，比如在a.py中使用b.py： import b 但是如果要import一个

Passing named arguments to a Javascript function [duplicate]

由 丶灬走出姿态 提交于 2019-12-12 15:15:24
问题 This question already has answers here : Is there a way to provide named parameters in a function call in JavaScript? (10 answers) Closed 4 years ago . Calling a Javascript function with something like someFunction(1, true, 'foo'); is not very clear without familiarity with the function. I have seen and used the style where comments are inserted to name the arguments: someFunction(/*itemsToAdd*/1, /*displayLabel*/ true, /*labelText*/ 'foo'); But when it gets beyond 3 or more parameters, it

python re can't find this grouped name

由 ⅰ亾dé卋堺 提交于 2019-12-11 05:25:40
问题 I try to give advice on the format of paper reference. For example, for academic dissertation, the format is: author. dissertation name[D]. place where store it: organization who hold the copy, year in which the dissertation published. obviously, there may be some punctuation in every items except for year. for example Smith. The paper name. The subtitle of paper[D]. United States: MIT, 2011 often, place where store it and year are missed, for example Smith. The paper name. The subtitle of

How to fix a dig command with status: REFUSED?

由 一曲冷凌霜 提交于 2019-12-10 21:18:09
问题 I need help fixing a status refused. I had a look at the named.conf and everything looks ok. I even changed allow-query to any , it used to be localhost . dig xxx.com @ns1.xxx.com ; <<>> DiG 9.8.3-P1 <<>> xxx.com @ns1.xxx.com ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: REFUSED, id: 41866 ;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0 ;; WARNING: recursion requested but not available ;; QUESTION SECTION: ;xxx.com. IN A ;; Query time: 29 msec

How to pass column name as parameter to function in dplyr?

由 ▼魔方 西西 提交于 2019-12-09 15:16:04
问题 I want to do the same as here but with dplyr and one more column. I want to selecting a column via a string variable, but on top I also want to select a second column normally. I need this because I have a function which selects a couple of columns by a given parameters. I have the following code as an example: library(dplyr) data(cars) x <- "speed" cars %>% select_(x, dist) 回答1: You can use quote() for the dist column x <- "speed" cars %>% select_(x, quote(dist)) %>% head # speed dist # 1 4

How to create named reference-type tuples?

由 …衆ロ難τιáo~ 提交于 2019-12-07 06:14:16
问题 The following line creates a named ValueTuple : var tuple = (a:1, b:2, c:3, d:4, e:5, f:6); Value types can not be passed around efficiently. Does C#7 offer a way to create named tuples of the Tuple type? 回答1: If you mean if there's a way to attach other names to the properties of System.Tuple<...> instances, no there isn't. Depending on why you want it, you might get around it by converting System.Tuple<...> instances to System.ValueTuple<...> instances using the ToValueTuple overloads in

Perl: Named parameters validation best practice

由 怎甘沉沦 提交于 2019-12-05 21:27:22
I am using named parameters in class method calls and was wondering if there is a best practice to make sure no unknown parameters are passed. Here's what I am doing sub classmethod { my $self = shift; my %args = ( "param1" => "default1", "param2" => "default2", @_ ) if (my @invalid = grep { !/^(param1|param2)$/ } keys %args) { croak "received unknown arg(s) ".join(",", @invalid)." from ".caller(); } } Is that a proper way to go forward, or could this cause a performance problem? Best, Marcus You could use Params::Validate . Another option is Params::Check If params are fixed, then its best to

How to create named reference-type tuples?

由 ε祈祈猫儿з 提交于 2019-12-05 08:33:59
The following line creates a named ValueTuple : var tuple = (a:1, b:2, c:3, d:4, e:5, f:6); Value types can not be passed around efficiently. Does C#7 offer a way to create named tuples of the Tuple type? If you mean if there's a way to attach other names to the properties of System.Tuple<...> instances, no there isn't. Depending on why you want it, you might get around it by converting System.Tuple<...> instances to System.ValueTuple<...> instances using the ToValueTuple overloads in TupleExtensions and back using the ToTuple overloads. If you don't really need the tuples, you can deconstruct
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