/en/ Recent content in Posts on Shu Hugo -- gohugo.io zh-cn Sat, 01 Feb 2020 00:00:00 +0000 /en/20200201_nature/ Sat, 01 Feb 2020 00:00:00 +0000 /en/20200201_nature/ Stop using the offensive virus names Inappropriate naming of the new human disease inevitably causes prejudice and discrimination upon particular people and undue fear of the diseases on global social media, although unintentionally. After the outbreak of Novel Coronavirus (2019-nCoV) causing a severe respiratory illness, some of the research papers and news on nature (such as Nature 577, 450 (2020), Nature 577, 605-607 (2020), doi: 10.1038/d41586-020-00146-w, doi: 10.1038/d41586-020-00180-8, doi: 10.1038/d41586-020-00253-8 and doi: 10. /en/20200110_calender/ Fri, 10 Jan 2020 12:05:38 +0000 /en/20200110_calender/ Is the current calendar is the best or only way to represent days? The days we experienced, undergoing, and expecting are recorded a piece of paper; we call it a calendar, where marks days of years, months, weeks, and holidays. The current calendar appearance that organized with month and weeks are very efficient to display the days of week and month. But, the calendar drops the original meaning of “Month”, which was related to the moon and moon phase, while the lunar calendar and lunisolar calendar (such as Chinese Calendar) still conserve the sense in the month. /en/20191119_sundials/ Tue, 19 Nov 2019 22:05:38 +0000 /en/20191119_sundials/ SUNDIALS: SUite of Nonlinear and DIfferential/ALgebraic Equation Solvers SUNDIALS (https://computing.llnl.gov/projects/sundials) is a very powerful mathematical library that is helpful in solving engineering and scientific problems efficiently. CVODE is one of the tools, aiming to solve the Ordinary Differential Equation, in C language. In the Simulator for Hydrologic Unstructured Domains (SHUD) model, the system of ODEs describing the hydrological processes is fully coupled and solved simultaneously at each time step ($ \Delta t=t_{n}-t_{n-1}$) using CVODE, a stiff solver based on Newton-Krylov iteration. /en/20191003_r_animation/ Thu, 03 Oct 2019 00:15:07 +0000 /en/20191003_r_animation/ This script is to demonstrate the capability and scheme to realise the animation. You have to prepare your own data for this animation script. Script for Global NDVI rm(list=ls()) library(RoundAndRound) # devtools::install_github('shulele/RoundAndRound') col.fun=function(x){ colorspace::terrain_hcl(x, l=c(65,95), power=c(1/3, 1.5)) } plotStar <- function(x, y, radius, angle=180, xyratio=1, ...){ i <- 1:11 alpha <- 2*pi / 10 r <- radius * (i %% 2 + 1)/2 omega <- alpha * i + angle * pi /180 invisible(mapply(function(a, b, . /en/20190627_ndvi/ Thu, 27 Jun 2019 00:00:00 +0000 /en/20190627_ndvi/ The normalized difference vegetation index (NDVI) is a simple graphical indicator that reflect the greenness and the heath condition of vegetations. The raw data is from NASA MOD13A. The global NDVI variation from 2002 to 2017. The NDVI varies from 2002 to 2017 in US (Continental) How to download the rawdata The code of the monthly NDVI from MODIS dataset is MOD13C2, so type the code below in your terminal and the wget will download all availalble data from server to you local matchine. /en/20190129roundandround/ Tue, 29 Jan 2019 00:00:00 +0000 /en/20190129roundandround/ I planed to write an R package and submit on CRAN, that can plot the planets orbiting in Solar System or satellite/moon orbiting around Earth. That package must plot the moving planets, the moon, moon phase and satellite in 2D or 3D canvas. In the future, it may calculate the orbit based on orbit mechanics. My son loves the song “The Wheels on the bus go round and round“, and he has an obsession with planets. /en/20190129kids-ucd/ Tue, 29 Jan 2019 00:00:00 +0000 /en/20190129kids-ucd/ external_link of the project Motivation of the project This is fantastic program to teach the local kids and lead them into the discovering sciences. Panoview of the Math&Science classroom. Week 03: Week 03: Jessica is writing students observation and discussion of plants in two different soils (Sperpentine and sandy loam). Week 05: Week 05: The growth condition of their beans.