Zheyuan Li

Zheyuan Li has asked 34 questions and find answers to 321 problems.

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Zheyuan Li questions

get x-value given y-value: general root finding for linear / non-linear interpolation function
Fast group-by simple linear regression
Remove code between #if 0 and #endif when exporting a C file to a new one
256-bit vectorization via OpenMP SIMD prevents compiler's optimization (say function inlining)?
C preprocessing fails to stop immediately after an #error
Write a trackable R function that mimics LAPACK's dgetrf for LU factorization
Without root access, run R with tuned BLAS when it is linked with reference BLAS
How to list all S3 methods defined in a specific package / namespace for a particular generic function
What is the algorithm behind R core's `split` function?
Finding stationary distribution of a markov process given a transition probability matrix

Zheyuan Li answers

R Warning 'length(x) = 2 > 1' in coercion to 'logical(1)'
generate N(0,1) using uniform(0,1) in R
Speed up setdiff(), intersect(), union() operations on vectors in R
GAM with "gp" smoother: how to retrieve the variogram parameters?
Build a sparse matrix with items coexistence frequency (to analyze cross-selling of products) [duplicate]
mgcv error: "x has insufficient unique values to support 3 knots: reduce k"
How to decrease machine precision .Machine$double.eps in R?
How to do Chi-square test correctly using chisq.test()?
Aligning Data frame with missing values
get x-value given y-value: general root finding for linear / non-linear interpolation function