denis-bz

Wind speeds at 100m in Bayern, ERA5 vs. globalwindatlas

Keywords: wind power, Germany, python, ERA5, globalwindatlas

Purpose: look at windspeed estimates at 100m in Bayern from two different sources:
ERA5: https://confluence.ecmwf.int/display/CKB/ERA5
GWA: https://globalwindatlas.info/area/Germany/Bayern

denis-bz

How efficient are wind, sun, biomass in the German provinces in 2019 - 2020 ?

Keywords: Renewable energy, wind energy, electricity, Germany

Purpose: look at the efficiency of electricity produced in the German provinces from sun, wind and biomass, with files from official data:
LAK, real: https://www.lak-energiebilanzen.de 2019, Länderarbeitskreis Energiebilanzen Bruttostromerzeugung nach Erneuerbaren Energieträgern
BMWK, max 31.12.2020,

denis-bz

Windspeeds and capacity factors in the Netherlands from wikipedia, KNMI and globalwindatlas

Keywords: wind, wind farm, wind speed, capacity factor, onshore, Netherlands, globalwindatlas, GWA, KNMI

What I want to do is show my neighbors around Munich that windfarms make more sense where there's more wind. GWA has a nice GUI, which everyone can understand. But are their wind speed and capacity factors accurate enough to convince anyone ?

nl.wikipedia Windturbines_in_Nederland,

denis-bz

Introduction to Netherlands wind data with xarray

Keywords: Netherlands, wind, wind speed, KNMI, python, xarray, data-carpentry

Purpose: introduce Netherlands wind data from KNMI, the Royal Netherlands$ Meteorological Institute, with the steps:

1. download 2 \.nc files by hand, one day and one gridpoint
2. look at them in xarray

denis-bz

Windspeeds and windfarms in Bayern

Keywords: wind power, Germany, Bayern, globalwindatlas, GWA

Purpose: I'm trying to show my neighbors around Munich that windfarms make more sense where there's more wind. To this end, here's a map of GWA windspeeds at 150m, together with the sites of 202 windfarms in Bayern:

denis-bz

Poisson2 - 4 I: nice test matrices for linear solvers and eigensolvers

Purpose: a simple generator of test matrices for linear solvers and eigensolvers

Keywords: sparse-matrix, linear-solver, eigensolver, arpack, nullspace, python

poisson2( n ) below generates sparse $n^2 \ x \ n^2$ matrices $A$ with $A$ symmetric (aka Hermitian) and positive-definite; solving $A \ x = b$ is then relatively easy. $A_4 = A - 4 I$ is more interesting: there are $n$ vectors $z_i$

denis-bz

#!/usr/bin/env python3
""" Usage:
python3 ssquery.py  '(posdef == 1)  &  (1000 <= rows <= 20000)'  posdef.csv
reads http://sparse.tamu.edu/files/ssstats.csv 
queries it
writes "posdef.csv" like

# SuiteSparse  posdef  &  (1000 <= rows <= 20000) 
id,group,name,rows,cols,nnz,real,bool,is2d3d,posdef,symm,nsymm,kind
29156,Boeing,msc01050,1050,1050,26198,1,0,1,1,1.0,1.0,structural

denis-bz

HUSL rgb_to_lch is for CIELuv, not CIELab

Keywords: color-space HUSL HSLuv CIELCh CIELuv CIELab max-chroma everyone-knows

_{Whenever something can be done in two ways, someone will be confused.}

There are two quite different color spaces: \

denis-bz

Windfarms in Germany from de.wikipedia

Keywords: wind power, Germany, python, globalwindatlas

Purpose: collect data on wind farms in Germany in a single .csv file, from https://de.wikipedia.org/wiki/Liste_von_Windkraftanlagen_in_Bayern etc.

The file windfarms-in-Germany.csv looks like this:

MW MW/Rad Nrad Year N E Land Lkr Typ Ort

denis-bz

Warping maps or images

Keywords: image raster resize rescale reproject Manhattan-grid regular-grid

We have a picture (image, raster) A, an array of colored pixels, and want to warp it to a new picture O of a different size or shape. Examples: Map projection, flat maps <-> globe; Image scaling.
There are hundreds of cases of these, and zillions of programs