Sean slwu89
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| fn_list <- function(y){ | |
| y$a <- y$a + 1 | |
| return(y) | |
| } | |
| fn_env <- function(y){ | |
| y$a <- y$a + 1 | |
| } | |
| x <- list(a=matrix(1:9,3,3),b=matrix(1:36,6,6)) |
slwu89
/ float_matching.R
Last active
September 30, 2021 17:50
operator to check if floats are in sets of other floats, for R
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| # for more info on comparing floats, this blog post is very informative: https://bitbashing.io/comparing-floats.html | |
| # for more info on how floating point mathematics compares to "real" mathematics, see https://www.tandfonline.com/doi/full/10.1080/10724117.2019.1611061 | |
| # helper function for approximate equality between floats | |
| approx_equal <- function(a, b, tol = sqrt(.Machine$double.eps)) { | |
| abs(a - b) <= tol | |
| } | |
| # use instead of the %in% operator to check if floats are in sets of other floats | |
| `%in_approx%` <- function(x, table) { |
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| rm(list=ls());gc();dev.off() | |
| library(sna) | |
| set.seed(4395834L) | |
| n <- 100 | |
| w1<-rgraph(n) #Draw the AR matrix | |
| w2<-w1 #Draw the MA matrix | |
| x<-matrix(rnorm(n*5),n,5) #Draw some covariates | |
| r1<-0.2 #Set the model parameters |
slwu89
/ std_function_RcppXPtr.cpp
Last active
March 19, 2020 01:38
for when you want to return a std::function to R wrapped in a struct to be evaluated later
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| #include <functional> | |
| #include <Rcpp.h> | |
| // [[Rcpp::plugins(cpp14)]] | |
| using my_lambda = std::function<double(const double)>; | |
| typedef struct lambda_st { | |
| my_lambda func; |
slwu89
/ xorshift.cpp
Last active
March 17, 2020 23:36
the PRNG is from code here: http://prng.di.unimi.it ; information on how to code URNG template class for STL's random header is here https://stackoverflow.com/questions/25129500/using-stdshuffle-with-custom-rng and https://www.boost.org/doc/libs/1_72_0/doc/html/boost_random/reference.html ; useful discussion is found on the dev's boards https://…
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| #include <random> | |
| #include <array> | |
| #include <iostream> | |
| #include <limits> | |
| #include <random> | |
| #include <Rcpp.h> | |
| // [[Rcpp::plugins(cpp14)]] |
slwu89
/ unique_array.cpp
Created
March 12, 2020 19:43
how to get unique elements and how many times they appear in an array of ints (for C, but compiled with C++)
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| // Example program | |
| #include <iostream> | |
| #include <string> | |
| int main(void) { | |
| int arr[13] = {1, 2, 2, 123121, 123121, 3, 5, 6 , 7, 7, 14, 2, 16}; | |
| int len = 13; | |
| int unique[len]; |
slwu89
/ shared_pointer_test.cpp
Created
December 4, 2019 20:32
checking that shared pointers are working right when mtple objects are sharing one resource, even when the first goes out of scope
slwu89
/ bridge1.cpp
Created
August 20, 2019 01:01
bridge-ish pattern with c++ when you want to have the different implementations store variable data using void*
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| #include <iostream> | |
| #include <iomanip> | |
| #include <string> | |
| #include <string> | |
| #include <memory> | |
| class impl_base { | |
| public: | |
| /* ctor & dtor */ |
slwu89
/ melancholia_i.R
Created
August 8, 2019 02:04
Melancholia I has a matrix on the wall. This finds its stationary distribution. (https://en.wikipedia.org/wiki/Melencolia_I)
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| xx <- matrix(c(16,3,2,13,5,10,11,8,9,6,7,12,4,15,14,1),nrow = 4,ncol = 4,byrow = T) | |
| xxx <- xx/rowSums(xx) | |
| xeig <- eigen(xxx) | |
| xvecs <- xeig$vectors | |
| lvecs <- MASS::ginv(xvecs) | |
| pi_eq <- lvecs[1,]/sum(lvecs[1,]) | |
| pi_eq |
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| // destination: array to fill the drawn "balls" | |
| // source: number of "balls" in each "urn" | |
| // n: number of draws to take | |
| // k: number of "urns" | |
| void rmhyper(int* destination, int const* source, int n, int k){ | |
| int sum, x, y; | |
| size_t i; | |
| if(n < 0 || k < 0){Rcpp::stop("Invalid parameters of distribution");} | |
| // total number of "balls" |