diff --git a/.gitignore b/.gitignore
index c191eae..b0077a8 100644
--- a/.gitignore
+++ b/.gitignore
@@ -26,6 +26,8 @@
 *.mtc
 *.mtc0
 
+*.pdf
+
 ## I want to keep some PDFs
 documents/Analysis I/*.pdf
 documents/Analysis II/*.pdf
diff --git a/documents/Analysis II/Analysis-II.tex b/documents/Analysis II/Analysis-II.tex
index 7c3498c..87e9b1d 100644
--- a/documents/Analysis II/Analysis-II.tex	
+++ b/documents/Analysis II/Analysis-II.tex	
@@ -3578,7 +3578,7 @@ Die allgemeine Lösung von ($\ast$) lautet also:
 \index{Anfangswertproblem}
 In diesem Paragraphen sei $n\in\mdn, I\subseteq\mdr$ ein Intervall und $a_0,\ldots,a_{n-1},b:I\to\mdr$
 stetig. Für $y\in C^n(I,\mdr)$ setze $Ly:=y^{(n)}+a_{n-1}(x)y^{(n-1)}+\cdots+a_0(x)y$.
-Die Dgl
+Die Differenzialgleichung
 \begin{align*}
 \tag D Ly=b
 \end{align*}
diff --git a/tikz/3d-function-continuous/3d-function-continuous.tex b/tikz/3d-function-continuous/3d-function-continuous.tex
index 2f45cd7..b26ab54 100644
--- a/tikz/3d-function-continuous/3d-function-continuous.tex
+++ b/tikz/3d-function-continuous/3d-function-continuous.tex
@@ -1,8 +1,6 @@
 \documentclass{article}
 \usepackage[pdftex,active,tightpage]{preview}
 \setlength\PreviewBorder{2mm}
-%\documentclass[varwidth=true, border=20pt]{standalone}
-%\documentclass{article}
 \usepackage{pgfplots}
 
 \begin{document}
@@ -23,6 +21,7 @@
     domain=-2:2,
     y domain=-2:2,
     samples=55, %60 : TeX capacity exceeded, sorry [main memory size=3000000].
+                % see also http://tex.stackexchange.com/a/7954/5645
     xlabel=$x$,
     ylabel=$y$,
     zlabel={$z$},
@@ -33,7 +32,7 @@
         height=0.25*\pgfkeysvalueof{/pgfplots/parent axis height},
         title={$f(x,y)$}
     }
-]
+    ]
       \addplot3[surf] {x*y*y/(x*x+y*y*y*y)};
     \end{axis} 
 \end{tikzpicture}
diff --git a/tikz/3d-helix/3d-helix.tex b/tikz/3d-helix/3d-helix.tex
new file mode 100644
index 0000000..b57f906
--- /dev/null
+++ b/tikz/3d-helix/3d-helix.tex
@@ -0,0 +1,36 @@
+\documentclass{article}
+\usepackage[pdftex,active,tightpage]{preview}
+\setlength\PreviewBorder{2mm}
+\usepackage{pgfplots}
+
+\begin{document}
+\begin{preview}
+\pgfplotsset{
+    colormap={whitered}{
+        color(0cm)=(white);
+        color(1cm)=(orange!75!red)
+    }
+}
+\begin{tikzpicture}
+    \begin{axis}[
+    colormap name=whitered,
+    width=15cm,
+    view={335}{50},
+    enlargelimits=false,
+    grid=major,
+    domain=-2:2,
+    y domain=-2:2,
+    samples=40, %60 : TeX capacity exceeded, sorry [main memory size=3000000].
+                % see also http://tex.stackexchange.com/a/7954/5645
+    xlabel=$x$,
+    ylabel=$y$,
+    zlabel={$z$}
+    ]
+        \addplot3+[domain=0:2*pi,samples y=0]
+            ({sin(deg(x))},
+             {cos(deg(x))},
+             {x});
+    \end{axis} 
+\end{tikzpicture}
+\end{preview}
+\end{document}
diff --git a/tikz/3d-helix/Makefile b/tikz/3d-helix/Makefile
new file mode 100644
index 0000000..744d09e
--- /dev/null
+++ b/tikz/3d-helix/Makefile
@@ -0,0 +1,31 @@
+SOURCE = 3d-helix
+DELAY = 80
+DENSITY = 300
+WIDTH = 500
+
+make:
+	pdflatex $(SOURCE).tex -output-format=pdf
+	make clean
+
+clean:
+	rm -rf  $(TARGET) *.class *.html *.log *.aux *.data *.gnuplot
+
+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