Vektorfunktion i tikz

Umiddelbart vil jeg foreslå dig at indtegne en kurve der indeholder de punkter du ønsker plottet. Jeg bruger pstricks, men man kan sikkert det samme i tikz. Kør nedenståendde LaTeX (og ikke pdfTeX) så skulle det blive smukt

\documentclass[10pt]{article}
\usepackage{pstricks,pstricks-add,pst-math,pst-xkey}
\begin{document}
\psset{xunit=3.0cm,yunit=3.0cm,algebraic=true,dotstyle=*,dotsize=3pt 0,linewidth=0.8pt,arrowsize=3pt 2,arrowinset=0.25}
\begin{pspicture*}(-1,-1)(3,1.2)
\psaxes[xAxis=true,yAxis=true,Dx=1,Dy=1,ticksize=-2pt 0,subticks=2]{->}(0,0)(-1,-1)(2,1.2)
\pscurve[linecolor=blue](0.950000000,0.90000000) (0.995773404,0.89305644) (1.037464020,0.87240107) (1.074808267,0.83855544) (1.107570043,0.79237411) (1.135542218,0.73502314) (1.158547941,0.66795060) (1.176441764,0.59285002) (1.189110557,0.51161765) (1.196474222,0.42630454) (1.198486204,0.33906480) (1.195133784,0.25210116) (1.186438155,0.16760940) (1.172454296,0.08772287) (1.153270615,0.01445867) (1.129008399,-0.05033335) (1.099821041,-0.10501722) (1.065893074,-0.14821222) (1.027438999,-0.17882770) (0.984701937,-0.19609064) (0.937952085,-0.19956517) (0.887485011,-0.18916355) (0.833619783,-0.16514842) (0.776696956,-0.12812615) (0.717076413,-0.07903152) (0.655135094,-0.01910414) (0.591264614,0.05014288) (0.525868780,0.12696107) (0.459361048,0.20941085) (0.392161900,0.29541041) (0.324696191,0.38278832) (0.257390460,0.46933834) (0.190670237,0.55287516) (0.124957349,0.63128951) (0.060667252,0.70260150) (-0.001793590,0.76501054) (-0.062030280,0.81694085) (-0.119661982,0.85708122) (-0.174324329,0.88441814) (-0.225671729,0.89826136) (-0.273379547,0.89826136) (-0.317146159,0.88441814) (-0.356694858,0.85708122) (-0.391775605,0.81694085) (-0.422166607,0.76501054) (-0.447675724,0.70260150) (-0.468141678,0.63128951) (-0.483435077,0.55287516) (-0.493459230,0.46933834) (-0.498150763,0.38278832) (-0.497480014,0.29541041) (-0.491451223,0.20941085) (-0.480102507,0.12696107) (-0.463505615,0.05014288) (-0.441765479,-0.01910414) (-0.415019547,-0.07903152) (-0.383436915,-0.12812615) (-0.347217258,-0.16514842) (-0.306589570,-0.18916355) (-0.261810710,-0.19956517) (-0.213163787,-0.19609064) (-0.160956361,-0.17882770) (-0.105518504,-0.14821222) (-0.047200712,-0.10501722) (0.013628310,-0.05033335) (0.076583983,0.01445867) (0.141268279,0.08772287) (0.207272245,0.16760940) (0.274178581,0.25210116) (0.341564285,0.33906480) (0.409003323,0.42630454) (0.476069322,0.51161765) (0.542338270,0.59285002) (0.607391194,0.66795060) (0.670816808,0.73502314) (0.732214115,0.79237411) (0.791194941,0.83855544) (0.847386391,0.87240107) (0.900433203,0.89305644) (0.950000000,0.90000000)
\end{pspicture*}
\end{document}

Jeg har regnet punkterne ud i R, og det ville næsten være nemmere i Excel med træk og slip.

Jeg håber det kan bruges.

Jeg ville umiddelbart nok også vælge samme metode (ville mene at man også kan plotte på samme måde med pgf/tikz), altså at man udregner punkter i et eksternt program. LaTeX er ikke beregnet til at skulle lave denne slags tegninger.

Kan jeg så ikke lige smide et tillægsspørgsmål ind.

Hvad er det for en kommando du giver R, for at den giver dig en liste med koordinater?

l=80

t<-seq(0,2*pi/1.3,length=l)

X<-matrix(rep(NA,2*l),nrow=l)

X[,1]<-0.6*cos(1.3*t)+0.6*sin(1.3*t)+0.35

X[,2]<-1.1*cos(1.3*t)^2-0.2

X

Og så bare copy'n'paste (Her bruger jeg WinEdt som har en behændig blokfunktion hvor man kan sætte kommaer imellem og parenteser udenom.

Tak

MEN!

Hvis man er kendt med R er der en meget nemmere måde at gøre det på. Skriv følgende i R:

l=80

t<-seq(0,2*pi/1.3,length=l)

X<-matrix(rep(NA,2*l),nrow=l)

X[,1]<-0.6*cos(1.3*t)+0.6*sin(1.3*t)+0.35

X[,2]<-1.1*cos(1.3*t)^2-0.2

X

write.table(X,file="C://LaTeX//ps-parameterkurve//test.txt", row.names = FALSE, col.names = FALSE)

Og her forestiller vi os at vores texfil ligger i C:\LaTeX\ps-parameterkurve. Nu kan vi bare skrive følgende i LaTeX

\documentclass[10pt]{article}
\usepackage{pstricks,pstricks-add,pst-math,pst-xkey}
\begin{document}
\psset{xunit=3.0cm,yunit=3.0cm,algebraic=true,dotstyle=*,dotsize=3pt,linewidth=0.8pt,arrowsize=5pt,arrowinset=0.25}
\readdata{\data}{test.txt}
\begin{pspicture*}(-1.1,-1.1)(3,1.2)
\psaxes[xAxis=true,yAxis=true,Dx=1,Dy=1,ticksize=-2pt 0,subticks=2]{->}(0,0)(-1,-1)(2,1.2)
\listplot[linecolor=blue,plotstyle=curve]{\data}
\end{pspicture*}
\end{document}

Blot husk at køre den tex => dvi => ps => pdf

Skal bare lægge til, at bruger man TikZ, kan man uden problemer køre tex => pdf. 

Hey Sigmund

Præcis hvad ville du gøre for at opnå det samme i tikz???

Nu er jeg så sen at svare, men følgende gør noget lignende. "Tickmærker" kan så tilføjes senere, hvis det ønskes; se mere i ftp://tug.ctan.org/pub/tex-archive/graphics/pgf/base/doc/generic/pgf/pgfmanual.pdf:

\documentclass[10pt]{article}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}
\draw[->] (-1,0) - - (2,0) (0,-1) - - (0,1.2);
\draw[color=blue] plot coordinates {(0.950000000,0.90000000) (0.995773404,0.89305644) (1.037464020,0.87240107) (1.074808267,0.83855544) (1.107570043,0.79237411) (1.135542218,0.73502314) (1.158547941,0.66795060) (1.176441764,0.59285002) (1.189110557,0.51161765) (1.196474222,0.42630454) (1.198486204,0.33906480) (1.195133784,0.25210116) (1.186438155,0.16760940) (1.172454296,0.08772287) (1.153270615,0.01445867) (1.129008399,-0.05033335) (1.099821041,-0.10501722) (1.065893074,-0.14821222) (1.027438999,-0.17882770) (0.984701937,-0.19609064) (0.937952085,-0.19956517) (0.887485011,-0.18916355) (0.833619783,-0.16514842) (0.776696956,-0.12812615) (0.717076413,-0.07903152) (0.655135094,-0.01910414) (0.591264614,0.05014288) (0.525868780,0.12696107) (0.459361048,0.20941085) (0.392161900,0.29541041) (0.324696191,0.38278832) (0.257390460,0.46933834) (0.190670237,0.55287516) (0.124957349,0.63128951) (0.060667252,0.70260150) (-0.001793590,0.76501054) (-0.062030280,0.81694085) (-0.119661982,0.85708122) (-0.174324329,0.88441814) (-0.225671729,0.89826136) (-0.273379547,0.89826136) (-0.317146159,0.88441814) (-0.356694858,0.85708122) (-0.391775605,0.81694085) (-0.422166607,0.76501054) (-0.447675724,0.70260150) (-0.468141678,0.63128951) (-0.483435077,0.55287516) (-0.493459230,0.46933834) (-0.498150763,0.38278832) (-0.497480014,0.29541041) (-0.491451223,0.20941085) (-0.480102507,0.12696107) (-0.463505615,0.05014288) (-0.441765479,-0.01910414) (-0.415019547,-0.07903152) (-0.383436915,-0.12812615) (-0.347217258,-0.16514842) (-0.306589570,-0.18916355) (-0.261810710,-0.19956517) (-0.213163787,-0.19609064) (-0.160956361,-0.17882770) (-0.105518504,-0.14821222) (-0.047200712,-0.10501722) (0.013628310,-0.05033335) (0.076583983,0.01445867) (0.141268279,0.08772287) (0.207272245,0.16760940) (0.274178581,0.25210116) (0.341564285,0.33906480) (0.409003323,0.42630454) (0.476069322,0.51161765) (0.542338270,0.59285002) (0.607391194,0.66795060) (0.670816808,0.73502314) (0.732214115,0.79237411) (0.791194941,0.83855544) (0.847386391,0.87240107) (0.900433203,0.89305644) (0.950000000,0.90000000)};
\end{tikzpicture}
\end{document}