added povray example

README.md

@@ -19,3 +19,12 @@ Requirements
 * You should have the latest LaTeX version. Here are
   [LaTeX installation instructions](http://martin-thoma.com/how-to-install-the-latest-latex-version/)
 * If you want to use the Makefiles, you have to have make
+
+POV-Ray
+=======
+Although POV-Ray has nothing to do with LaTeX, I decided to add
+some images here
+
+* [POV-Ray Documentation](http://www.povray.org/documentation/)
+* [Ubuntuusers.de](http://wiki.ubuntuusers.de/POV-Ray) - German installation instructions
+* [Many examples](http://www.f-lohmueller.de/)

documents/math-sylvester-diagonal-matrix/math-sylvester-diagonal-matrix.tex

@@ -1,6 +1,6 @@
 \documentclass{article}
 \usepackage[pdftex,active,tightpage]{preview}
-\setlength\PreviewBorder{2mm}
+\setlength\PreviewBorder{0mm}
 
 \usepackage{amsmath,array}
 \renewcommand\arraycolsep{4pt} % default value: 6pt
@@ -9,36 +9,31 @@
 \begin{document}
 \begin{preview}
 \begin{equation*}
+S^T \cdot A \cdot S =
 \left( \,
 \begin{array}{r@{}r@{}r r r}  % @{} is used twice to suppress intercolumn whitespace
-  \overbrace{
-    \boxed{
+  \underbrace{
       \begin{array}{rrr}    % First block (1)
         1 &        &   \\
           & \ddots &   \\
           &        & 1 \\
       \end{array}
-    }
-  }^{r_+(s)-mal} \\
+  }_{r_+(s)-mal}\\
   & 
   \underbrace{
-    \boxed{
       \begin{array}{rrr}    % Second block (-1)
         -1 &        &   \\
            & \ddots &   \\
            &        & -1\\
       \end{array}
-    }
   }_{r_{-}(s)-mal} \\
   & & 
   \underbrace{
-    \boxed{
       \begin{array}{rrr}    % Third block
         0  &        &  \\
            & \ddots &  \\
            &        & 0\\
       \end{array}
-    }
   }_{r_0(s)-mal} \\
 \end{array}\,\right)
 \end{equation*}

povray/ellipsoid/Makefile

@@ -0,0 +1,31 @@
+SOURCE = ellipsoid
+DELAY = 80
+DENSITY = 300
+WIDTH = 500
+
+make:
+	povray $(SOURCE).pov
+	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

povray/ellipsoid/ellipsoid.pov

@@ -0,0 +1,24 @@
+#include "colors.inc"
+#include "stones.inc"
+
+camera {
+  location <10, 10, 0>
+  look_at <0, 0, 0>
+}
+
+plane {
+  y, 0
+  pigment { checker color Gray color White  }
+}
+
+sphere {
+  <0, 0, 0>, 4  // center and radius
+  pigment { color White }
+  texture {T_Stone1}
+  finish {
+    reflection 0.1
+    phong 0.3
+  }
+}
+light_source { <5, 10, 10> color White }
+light_source { <10, 10, 5> color White }

tikz/ellipsoid/Makefile

@@ -0,0 +1,31 @@
+SOURCE = ellipsoid
+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

tikz/ellipsoid/ellipsoid.tex

@@ -0,0 +1,45 @@
+\documentclass{article}
+\usepackage[pdftex,active,tightpage]{preview}
+\setlength\PreviewBorder{2mm}
+\usepackage{pgfplots}
+\usepackage{units}
+\pgfplotsset{compat=1.3}% <-- moves axis labels near ticklabels
+                        % (respects tick label widths)
+\usepackage{tikz}
+\usetikzlibrary{arrows, positioning, calc, intersections, decorations.markings}
+
+\usepackage{xcolor}
+\definecolor{horizontalLineColor}{HTML}{008000}
+\definecolor{verticalLineColor}{HTML}{FF0000}
+ 
+\begin{document}
+
+% Define this as a command to ensure that it is same in both cases
+\newcommand*{\ShowIntersection}[2]{
+\fill 
+    [name intersections={of=#1 and #2, name=i, total=\t}] 
+    [red, opacity=1, every node/.style={above left, black, opacity=1}] 
+    \foreach \s in {1,...,\t}{(i-\s) circle (2pt)
+        node [above left] {\s}};
+}
+
+\begin{preview}
+\begin{tikzpicture}
+    \begin{axis}[
+        grid=both,
+        minor tick num=1,
+        xlabel=$x$,
+        ylabel=$y$,
+        zlabel=$z$,
+        %label distance=0mm,
+        %width=8cm, height=7cm,     % size of the image
+        axis lines=left,
+        %tick style={draw=none},
+        %xticklabels={,,},
+        %yticklabels={,,}
+    ]
+      \addplot3[surf] {-(x*x/16+y*y/4-1)};
+    \end{axis} 
+\end{tikzpicture}
+\end{preview}
+\end{document}