Zheyuan Li

Zheyuan Li has asked 34 questions and find answers to 316 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

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
Custom Link function works for GLM but not mgcv GAM
"non-finite value supplied by optim" error when using betareg
Factor levels default to 1 and 2 in R | Dummy variable
Is it possible to control the degrees of freedom for the smooth functions in a GAM fit in R, and if so, how?
Idiomatic matrix type conversion, say convert Integer (0/1) matrix to boolean matrix