Zeitgleichung.png
Size of this preview:
800 × 533 pixels
.
Other resolutions:
320 × 213 pixels
|
640 × 427 pixels
|
1,024 × 683 pixels
|
1,200 × 800 pixels
.
Description Zeitgleichung.png |
English:
Graph showing the
equation of time
(red solid line) along with its two main components plotted separately:
|
Date | |
Source | [1] and other sources on the net. created with GNU R, see source below |
Author | Thomas Steiner |
Permission
( Reusing this file ) |
Thomas Steiner put it under the CC-by-SA 2.5 . |
Other versions | File:Zeitgleichung mit Datumsangaben.jpg |
This
graph
image could be re-created
using
vector graphics
as an
SVG
file
. This has several advantages; see
Commons:Media for cleanup
for more information. If an SVG form of this image is available, please upload it and afterwards replace this template with
{{
vector version available
|
new image name
}}
.
It is recommended to name the SVG file “Zeitgleichung.svg”—then the template Vector version available (or Vva ) does not need the new image name parameter. |
This file is licensed under the
Creative Commons
Attribution-Share Alike 2.5 Generic
license.
-
You are free:
- to share – to copy, distribute and transmit the work
- to remix – to adapt the work
-
Under the following conditions:
- attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
- share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible license as the original.
R-source:
#formulas, equations and notation from http://homeweb2.unifr.ch/hungerbu/pub/sonnenuhr/sundial.ps # and by the paper of C. Blatter (http://dz-srv1.sub.uni-goettingen.de/sub/digbib/loader?did=D241775) epsilon=23.45*2*pi/360 alpha =78.5 *2*pi/360 kappa =0.016722 mu<-function(t,epsilon,alpha,kappa) { zaehl= -sin(delta(t,kappa))+tan(epsilon/2)^2*sin(2*(t-alpha)+delta(t,kappa)) nenn = cos(delta(t,kappa))+tan(epsilon/2)^2*cos(2*(t-alpha)+delta(t,kappa)) return( atan(zaehl/nenn) ) } # approximation by Blatter psi<-function(t) { return(t+delta(t)) } delta<-function(t,kappa) { return( 2*sin(t)*kappa+5/4*sin(2*t)*kappa^2 ) } png(filename="Zeitgleichung.png", width=1024, height=768, pointsize=12) par(bg="whitesmoke") time=seq(-0.6,2*pi+0.4,length=365+(0.6+0.4)/(2*pi)*365) da<-paste("1.",as.character(seq(1,12,by=2)),".07",sep="") da<-as.Date(c(da,"1.1.08"),"%d.%m.%y") #umrechungsfaktor: 24h=2*pi plot(time,mu(time,epsilon,alpha,kappa)*24*60/(2*pi),type="l",col="red",xlab="Tag",ylab="Zeitgleichung in Minuten",main="Zeitgleichung: wahre Ortszeit - mittlere Ortszeit",cex.main=1.5,lwd=3,xaxt="n",xaxs="i",xlim=range(time)) lines(time,mu(time,epsilon=0,alpha,kappa)*24*60/(2*pi),lwd=2,col="navy",lty="dotdash") lines(time,mu(time,epsilon,alpha,kappa=0)*24*60/(2*pi),lwd=2,col="purple",lty="dashed") #grid abline(h=c(-15,-10,-5,5,10,15),lty="dotted",col="grey") abline(h=0,lty="solid",col="grey33") tage=cumsum(c(0,31,28,31,30,31,30,31,31,30,31,30,31))/365-3/365 abline(v=tage*2*pi,lty="dotted",col="grey") axis(1,at=seq(0,2*pi,length=7)-3*2*pi/365,labels=as.character(da,"1. %b")) legend(x=5.5,y=-10.9,legend=c("Zeitgleichung","ohne Ekliptik","auf Kreisbahn"),col=c("red","navy","purple"),lwd=c(3,2,2),lty=c("solid","dotdash","dashed")) dev.off()