mean

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I've been hunting for a convenient way to sample from a multivariate normal distribution. Does anyone know of a readily available code snippet to do that? For matrices/vectors, I'd prefer to use Boost or Eigen or another phenomenal library I'm not familiar with, but I could use GSL in a pinch. I'd also like it if the method accepted nonnegative -definite covariance matrices rather than requiring positive-definite (e.g., as with the Cholesky decomposition). This exists in MATLAB, NumPy, and others, but I've had a hard time finding a ready

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I'm getting an IMPORT ERROR with the following error message in Django debug mode /usr/local/lib/python2.6/dist-packages/lxml-2.3-py2.6-win32.egg/lxml/objectify.pyd: invalid ELF header What does this mean and how do I fix it? Google is revealing not very much at the moment. This error is coming from this package I am using in my Django app Update I'm using ubuntu and Python2.6 回答1: The error means the objectify.pyd is not a valid shared library. You seem to have lxml compiled for different version of python from what you are running.

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: How is Accuracy defined when the loss function is mean square error? Is it mean absolute percentage error - en.wikipedia.org/wiki/Mean_absolute_percentage_error ? The model I use has output activatoin linear and is compiled with loss= mean_squared_error model.add(Dense(1)) model.add(Activation('linear')) # number model.compile(loss='mean_squared_error', optimizer='adam', metrics=['accuracy']) and the output looks like this: Epoch 99/100 1000/1000 [==============================] - 687s 687ms/step - loss: 0.0463 - acc: 0.9689 - val_loss: 3

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I have seen the use of %>% (percent greater than percent) function in some packages like dplyr and rvest . What does it mean? Is it a way to write closure blocks in R? 回答1: %...% operators . %>% has no builtin meaning but the user (or a package) is free to define operators of the form %whatever% in any way they like. For example, this function will return a string consisting of its left argument followed by a comma and space and then it's right argument. "%,%" The base of R provides %*% (matrix mulitiplication), %/% (integer division), %in%

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: In Python, I have a pandas DataFrame similar to the following: Item | shop1 | shop2 | shop3 | Category ------------------------------------ Shoes| 45 | 50 | 53 | Clothes TV | 200 | 300 | 250 | Technology Book | 20 | 17 | 21 | Books phone| 300 | 350 | 400 | Technology Where shop1, shop2 and shop3 are the costs of every item in different shops. Now, I need to return a DataFrame, after some data cleaning, like this one: Category (index)| size| sum| mean | std ---------------------------------------- where size is the number of items in each

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: So I tried to import aurioTouch into my app and I keep getting this error saying "unknown type name 'class' did you mean "Class"? My bridging header file: #import "AudioController.h" #import "BufferManager.h" #import "FFTHelper.h" #import "DCRejectionFilter.h" I tried changing this to .mm for all these files but it doesn't solve my issue. Anyone have any ideas why this is happening? 回答1: To mix C++ and Objective-C you need to use the .mm extension . If, however, your class is only C++ (and only includes C/C++ headers) then you can use the

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I have tried several things to make ggplot plot barcharts with means derived from factors in a dataframe, but i wasnt successful. If you consider: df <- as.data.frame(matrix(rnorm(60*2, mean=3,sd=1), 60, 2)) df$factor <- c(rep(factor(1:3), each=20)) I want to achieve a stacked, relative barchart like this: This chart was created with manually calculating group means in a separate dataframe, melting it and using geom_bar(stat="identity", position = "fill) and scale_y_continuous(labels = percent_format()) . I havent found a way to use stat

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 由 翻译 强力驱动 问题: While browsing some typescript code of @ng-bootstrap I have found pipe( | ) operator. export declare const NGB_PRECOMPILE : ( typeof NgbAlert | typeof NgbTooltipWindow )[]; What is the use of pipe( | ) operator in typescript? 回答1: This is called union type in typescript. A union type describes a value that can be one of several types. Have a look at this example: class Test1 { public a : string } class Test2 { public b : string } class Test3 { } let x : ( typeof Test1 | typeof Test2 )[]; x = [ Test1 ]; //ok x = [ Test1 , Test2 ]; /

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: What does the statement string::npos mean here found=str.find(str2); if (found!=string::npos) cout 回答1: It means not found. It is usually defined like so: static const size_t npos = -1; It is better to compare to npos instead of -1 because the code is more legible. 回答2: string::npos is a constant (probably -1 ) representing a non-position. It's returned by method find when the pattern was not found. 回答3: The document for string::npos says: npos is a static member constant value with the greatest possible value for an element of type size_t.

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I'm new to Typescript and I'm reading over someone else's code and having trouble with this declaration: private somevar: { [s: string]: string }; What type is this? Square brackets indicate an array, but I'm confused about exactly what shape this would be in. 回答1: It's an indexable type. Looking at this variable definition's type expression: let myIndexVar: { [key: string]: number; }; : { ... } means it's an object. [key: string]: number; is the index signature of the object. Within the index signature: [key: string] defines the name of the