# Questions tagged [r]

R is a language and environment for statistical computing and graphics that provides a wide variety of statistical (linear and nonlinear modelling, classical statistical tests, time-series analysis, classification, clustering, ...) and graphical techniques and is highly extensible. (Questions about problems and bugs encountered when using R belong on the R-help mailing list (https://stat.ethz.ch/mailman/listinfo/r-help).)

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### How to initialize Eigen C++ parameters within for-loop? [closed]

I am new to Eigen C++ programming. I am trying to create an Rcpp function to call from R. The function takes a list of matrices (Xlst), and two lists of vectors (ylst and smwlst). In each for-loop ...
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### Getting gradient from voxel, is it possible and how?

The R package rmarchingcubes implements a marching cubes algorithm. Given a voxel contructed from a function defining an isosurface, it returns a 3d mesh with some vertex normals. When I plot this ...
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### Finding matrix of a linear transformation using R programing

The full question is: Let {u1, u2,···, un} and {x1, x2,···, xm} be bases for Rn and Rm respectively. Let T:Rn→Rm be the linear transformation whose associated matrix with respect to the above bases is ...
1 vote
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### Efficient multidimensional numerical integration in R and C++

I'm trying to perform a 4-dimensional numerical integration in R using a function I wrote in C++ code which is then sourced in <...
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### How are scientific computing workflows faring on Apple's M1 hardware

The initial wave of reviews for Apple's M1 hardware are out, and there's lots of generic benchmarks and data on workflows on professional programs for creative users, but I haven't seen anyone talking ...
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### Problem of half-planes intersection

Consider the half-planes $\{x \leqslant 2\}$ and $\{x+y \leqslant 3\}$. These two half-planes are coded with the R package 'rcdd' as follows: ...
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### (Lack of) Availability of Finite-Difference library for simple 2D PDEs

I would like to solve two types of simple 2D problems, namely the stationary heat equation on an L shaped geometry like this: And also compute the magnetostactic field in an air gap of the following ...
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### How to solve for underlying function from discrete data set containing integral of that function

New to Computational Science, I hope I'm on the right exchange network for this question. I have a time series data set that contains the sum of a source data set representing an exponential decay ...
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### Storing a large, sparse array for R and Python

I've been working in R but sometimes switching to python. I'd like a more inter-language portable way of storing a large array than a csv file. (The particular csv file I'm dealing with is about 10^6 ...
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