added imagry

asymptote/topology-r-spiral-covering-s/Makefile

@@ -4,6 +4,7 @@ DENSITY = 300
 WIDTH = 512
 
 make:
+	make clean
 	pdflatex $(SOURCE).tex -output-format=pdf
 	asy $(SOURCE)-*.asy
 	asy $(SOURCE)-*.asy
@@ -11,7 +12,7 @@ make:
 	make clean
 
 clean:
-	rm -rf  $(TARGET) *.class *.html *.log *.aux *.data *.gnuplot *.out *.prc *.pre *.asy
+	rm -rf  $(TARGET) *.class *.html *.log *.aux *.data *.gnuplot *.out *.prc *.pre *.asy topology-r-spiral-covering-s-1_0.pdf topology-r-spiral-covering-s-1+0_0.pdf topology-r-spiral-covering-s-1.tex
 
 gif:
 	pdfcrop $(SOURCE).pdf

asymptote/topology-r-spiral-covering-s/topology-r-spiral-covering-s.tex

@@ -26,8 +26,10 @@ real phix = 0.1;
 real phim = 6.7;
 
 // spiral
-path3 spiral = graph(x,y,z,1,phim,operator ..);
-draw(spiral,Arrow3);
+path3 spiral1 = graph(x,y,z,0.9,1,operator ..);
+draw(spiral1,dotted);
+path3 spiral2 = graph(x,y,z,1,phim,operator ..);
+draw(spiral2,Arrow3);
 
 // blue circle
 draw(unitcircle3, blue);
@@ -46,9 +48,9 @@ dot(px);
 label("$x$",px,S);
 
 // axes and labels
-xaxis3("",red);
-yaxis3("",red);
-zaxis3("",red);
+xaxis3("",red,Arrow3);
+yaxis3("",red,Arrow3);
+zaxis3("",red,Arrow3);
 
 label("$\mathbb{R}$",(1,-1,4));
 

asymptote/torus-three-paths/Makefile

@@ -0,0 +1,35 @@
+SOURCE = torus-three-paths
+DELAY = 80
+DENSITY = 300
+WIDTH = 512
+
+make:
+	make clean
+	pdflatex $(SOURCE).tex -output-format=pdf
+	asy $(SOURCE)-*.asy
+	asy $(SOURCE)-*.asy
+	pdflatex $(SOURCE).tex -output-format=pdf
+	make clean
+
+clean:
+	rm -rf  $(TARGET) *.class *.html *.log *.aux *.data *.gnuplot *.out *.prc *.pre *.asy $(SOURCE)-1_0.pdf $(SOURCE)1+0_0.pdf $(SOURCE)-1.tex
+
+gif:
+	pdfcrop $(SOURCE).pdf
+	convert -verbose -delay $(DELAY) -loop 0 -density $(DENSITY) $(SOURCE)-crop.pdf $(SOURCE).gif
+	make clean
+
+png:
+	make
+	make svg
+	inkscape $(SOURCE).svg -w $(WIDTH) --export-png=$(SOURCE).png
+
+transparentGif:
+	convert $(SOURCE).pdf -transparent white result.gif
+	make clean
+
+svg:
+	#inkscape $(SOURCE).pdf --export-plain-svg=$(SOURCE).svg
+	pdf2svg $(SOURCE).pdf $(SOURCE).svg
+	# Necessary, as pdf2svg does not always create valid svgs:
+	inkscape $(SOURCE).svg --export-plain-svg=$(SOURCE).svg

asymptote/torus-three-paths/Readme.md

@@ -0,0 +1,8 @@
+Compiled example
+----------------
+![Example](topology-r-spiral-covering-s.png)
+
+Credits
+-------
+
+This graph was created by [Alex](http://tex.stackexchange.com/users/22467/alex) ([source](http://tex.stackexchange.com/a/149706/5645))

asymptote/torus-three-paths/torus-three-paths.tex

@@ -0,0 +1,51 @@
+\documentclass[margin=1cm]{standalone}
+\usepackage{asymptote}
+\begin{document}
+\begin{asy}
+settings.render = 8;
+settings.prc = false;
+
+import graph3;
+import contour;
+size3(8cm);
+
+currentprojection = orthographic(10,1,4);
+defaultrender = render(merge = true);
+
+// create torus as surface of rotation
+int umax = 40;
+int vmax = 40;
+surface torus = surface(Circle(c=2Y, r=0.6, normal=X, n=vmax), c=O, axis=Z, n=umax);
+torus.ucyclic(true);
+torus.vcyclic(true);
+
+pen meshpen = 0.3pt + gray;
+
+draw(torus, surfacepen=material(diffusepen=white+opacity(0.6), emissivepen=white));
+for (int u = 0; u < umax; ++u)
+  draw(torus.uequals(u), p=meshpen);
+for (int v = 0; v < vmax; ++v)
+  draw(graph(new triple(real u) {return torus.point(u,v); }, 0, umax, operator ..),
+       p=meshpen);
+
+pair a = (floor(umax/2) + 2, 3);
+dot(torus.point(a.x, a.y), L="$a$", align=W);
+pair b = (5, floor(vmax/2));
+dot(torus.point(b.x, b.y), L="$b$", align=2Z + X);
+
+path3 abpath(int ucycles, int vcycles) {
+  pair bshift = (ucycles*umax, vcycles*vmax);
+  triple f(real t) {
+    pair uv = (1-t)*a + t*(b+bshift);
+    return torus.point(uv.x, uv.y);
+  }
+  return graph(f, 0, 1, operator ..);
+}
+
+real linewidth = 0.8pt;
+
+draw(abpath(0,0), p=linewidth + orange);
+draw(abpath(1,0), p=linewidth + red);
+draw(abpath(1,-1), p=linewidth + darkgreen);
+\end{asy}
+\end{document}