added two images

tikz/center-line/Makefile

@@ -0,0 +1,35 @@
+SOURCE = center-line
+DELAY = 80
+DENSITY = 300
+WIDTH = 512
+
+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:
+	make
+	#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
+	rsvg-convert -a -w $(WIDTH) -f svg $(SOURCE).svg -o $(SOURCE)2.svg
+	inkscape $(SOURCE)2.svg --export-plain-svg=$(SOURCE).svg
+	rm $(SOURCE)2.svg

tikz/center-line/center-line.tex

@@ -0,0 +1,75 @@
+\documentclass{article}
+\usepackage[pdftex,active,tightpage]{preview}
+\setlength\PreviewBorder{2mm}
+\usepackage{tikz}
+\usepackage{tkz-fct}
+\usetikzlibrary{shapes.misc}
+\usetikzlibrary{shapes, calc, shapes,snakes} 
+\usepackage{amsmath,amssymb}
+
+\begin{document}
+\begin{preview}
+\begin{tikzpicture}[cross/.style={    thick,
+    draw=gray,
+    cross out,
+    inner sep=0pt,
+    minimum width=4pt,
+    minimum height=4pt},
+dot/.style={    thick,
+    draw=gray,
+	circle,
+	fill=black,
+    inner sep=0pt,
+    minimum width=4pt,
+    minimum height=4pt}]
+\node at (0,3) {Schritt 1:};
+\foreach \point in {(2,3),(4,3),(6,3),(8,3),(10,3),(12,3)}{
+	\node[cross] at \point {};
+}
+\foreach \point in {(3,3),(11,3)}{
+	\node[dot] at \point {};
+}
+
+\draw[->] (2,3) edge[bend left] (2.9,3);
+\draw[->] (12,3) edge[bend right] (11.1,3);
+%%%%%%%%%%%%%%%%%%%%%%%%
+\node at (0,2) {Schritt 2:};
+\foreach \point in {(3,2),(4,2),(6,2),(8,2),(10,2),(11,2)}{
+	\node[cross] at \point {};
+}
+\foreach \point in {(3.5,2),(4.33,2),(9.66,2),(10.5,2)}{
+	\node[dot] at \point {};
+}
+
+\draw[->] (3,2) edge[bend left] (3.4,2);
+\draw[->] (4,2) edge[bend left] (4.2,2);
+\draw[->] (11,2) edge[bend right] (10.6,2);
+\draw[->] (10,2) edge[bend right] (9.73,2);
+%%%%%%%%%%%%%%%%%%%%%%%%
+\node at (0,1) {Schritt 3:};
+\node[cross] at (7,1) {};
+
+\node at (0,1.6) {$\vdots$};
+\node at (0,2.6) {$\vdots$};
+
+
+% Brace
+\draw [decorate,decoration={brace,amplitude=6pt},yshift=3pt]
+(2,3) -- (4,3) node [black,midway,yshift=12pt] 
+{\footnotesize 200m};
+\draw [decorate,decoration={brace,amplitude=6pt},yshift=3pt]
+(4,3) -- (6,3) node [black,midway,yshift=12pt] 
+{\footnotesize 200m};
+\draw [decorate,decoration={brace,amplitude=6pt},yshift=3pt]
+(6,3) -- (8,3) node [black,midway,yshift=12pt] 
+{\footnotesize 200m};
+\draw [decorate,decoration={brace,amplitude=6pt},yshift=3pt]
+(8,3) -- (10,3) node [black,midway,yshift=12pt] 
+{\footnotesize 200m};
+\draw [decorate,decoration={brace,amplitude=6pt},yshift=3pt]
+(10,3) -- (12,3) node [black,midway,yshift=12pt] 
+{\footnotesize 200m};
+
+\end{tikzpicture}
+\end{preview}
+\end{document}

tikz/center-line/tikz.py

@@ -0,0 +1,40 @@
+from random import uniform
+import random
+import math
+
+n = 5
+xMin, yMin = 0, 0
+xMax, yMax = 5, 5
+xSum = 0
+ySum = 0
+coordinates = []
+
+random.seed(42)
+
+for i in range(n):
+	x = uniform(xMin, xMax)
+	y = uniform(yMin, yMax)
+	xSum += x
+	ySum += y
+	coordinates.append((x,y))
+
+center = (float(xSum) / n, float(ySum) / n)
+
+cx, cy = center
+pointCoords = ""
+for p in coordinates:
+	px, py = p	
+	newP = "(%.2f,%.2f)," % (px, py)
+	pointCoords = newP + pointCoords
+	deltaY = cy-py
+	deltaX = cx-px
+	length = (deltaY**2+deltaX**2)**0.5
+	sinAlpha = deltaY/length
+	cosAlpha = deltaX/length
+	print("\draw[->] (%.2f,%.2f) -- (%.2f,%.2f);" % (px, py, px+cosAlpha*length*0.80, py+sinAlpha*length*0.80))
+
+print("\\node[circle,inner sep=1pt,fill]  at (%.2f,%.2f) {};" % (cx, cy))
+
+print("\\foreach \point in {" + pointCoords + "}{")
+print("\\node[dot] at \point {};")
+print("}")

tikz/center-two-cluster/Makefile

@@ -0,0 +1,35 @@
+SOURCE = center-two-cluster
+DELAY = 80
+DENSITY = 300
+WIDTH = 512
+
+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:
+	make
+	#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
+	rsvg-convert -a -w $(WIDTH) -f svg $(SOURCE).svg -o $(SOURCE)2.svg
+	inkscape $(SOURCE)2.svg --export-plain-svg=$(SOURCE).svg
+	rm $(SOURCE)2.svg

tikz/center-two-cluster/center-two-cluster.tex

@@ -0,0 +1,47 @@
+\documentclass{article}
+\usepackage[pdftex,active,tightpage]{preview}
+\setlength\PreviewBorder{2mm}
+\usepackage{tikz}
+\usepackage{tkz-fct}
+\usetikzlibrary{shapes.misc}
+\usetikzlibrary{shapes, calc, shapes,snakes} 
+\usepackage{amsmath,amssymb}
+
+\begin{document}
+\begin{preview}
+\begin{tikzpicture}[scale=0.1,dot/.style={    thick,
+    draw=gray,
+    cross out,
+    inner sep=0pt,
+    minimum width=4pt,
+    minimum height=4pt}]
+
+\draw[->] (-3.43,8.41) -- (-0.69,1.68);
+\draw[->] (-5.48,3.65) -- (-1.10,0.73);
+\draw[->] (2.52,-7.45) -- (0.50,-1.49);
+\draw[->] (2.97,-3.76) -- (0.59,-0.75);
+\draw[->] (3.43,-0.85) -- (0.69,-0.17);
+\draw[->] (15.00,0.00) -- (3.00,0.00);
+\node[circle,inner sep=1pt,fill]  at (0.00,0.00) {};
+\foreach \point in {(15.00,0.00),(3.43,-0.85),(2.97,-3.76),(2.52,-7.45),(-5.48,3.65),(-3.43,8.41)}{
+\node[dot] at \point {};
+}
+\draw[->] (39.63,0.85) -- (39.93,0.17);
+\draw[->] (43.27,-8.94) -- (40.65,-1.79);
+\draw[->] (38.54,9.68) -- (39.71,1.94);
+\draw[->] (34.19,-5.01) -- (38.84,-1.00);
+\draw[->] (44.37,3.43) -- (40.87,0.69);
+\draw[->] (25.00,0.00) -- (37.00,0.00);
+\node[circle,inner sep=1pt,fill]  at (40.00,0.00) {};
+\foreach \point in {(25.00,0.00),(44.37,3.43),(34.19,-5.01),(38.54,9.68),(43.27,-8.94),(39.63,0.85)}{
+\node[dot] at \point {};
+}
+\node[circle,inner sep=1pt,fill]  at (40.00,0.00) {};
+\foreach \point in {(15,0), (35,0)}{
+\node[dot] at \point {};
+}
+
+\end{tikzpicture}
+\end{preview}
+\end{document}
+

tikz/center-two-cluster/tikz.py

@@ -0,0 +1,129 @@
+from random import uniform
+import random
+import math
+
+print """\documentclass{article}
+\usepackage[pdftex,active,tightpage]{preview}
+\setlength\PreviewBorder{2mm}
+\usepackage{tikz}
+\usepackage{tkz-fct}
+\usetikzlibrary{shapes.misc}
+\usetikzlibrary{shapes, calc, shapes,snakes} 
+\usepackage{amsmath,amssymb}
+
+\\begin{document}
+\\begin{preview}
+\\begin{tikzpicture}[scale=0.1,dot/.style={    thick,
+    draw=gray,
+    cross out,
+    inner sep=0pt,
+    minimum width=4pt,
+    minimum height=4pt}]
+"""
+
+def getPositionFromOffset(px, py, angle, radius):
+    x = px + radius * math.cos(math.radians(angle))
+    y = py + radius * math.sin(math.radians(angle))
+    return (x, y)
+
+n = 5
+xSum = 0
+ySum = 0
+coordinates = [(0,0)]
+
+random.seed(13)
+
+for i in range(n-1):
+	radius = uniform(0,20)
+	angle = uniform(0, 360)
+	px, py = coordinates[-1]
+	x, y = getPositionFromOffset(px, py, angle, radius)
+	xSum += x
+	ySum += y
+	coordinates.append((x,y))
+
+center = (float(xSum) / n, float(ySum) / n)
+
+cx, cy = center
+coordinates.append((cx+15, cy))
+
+pointCoords = ""
+for p in coordinates:
+	px, py = p	
+	px -= cx
+	py -= cy
+	newP = "(%.2f,%.2f)," % (px, py)
+	pointCoords = newP + pointCoords
+	deltaY = 0-py
+	deltaX = 0-px
+	length = (deltaY**2+deltaX**2)**0.5
+	sinAlpha = deltaY/length
+	cosAlpha = deltaX/length
+	print("\draw[->] (%.2f,%.2f) -- (%.2f,%.2f);" % (px, py, px+cosAlpha*length*0.80, py+sinAlpha*length*0.80))
+
+print("\\node[circle,inner sep=1pt,fill]  at (%.2f,%.2f) {};" % (0, 0))
+
+print("\\foreach \point in {" + pointCoords[:-1] + "}{")
+print("\\node[dot] at \point {};")
+print("}")
+
+################################################################################
+random.seed(17)
+xSum = 0
+ySum = 0
+coordinates = [(0,0)]
+for i in range(n-1):
+	radius = uniform(0,20)
+	angle = uniform(0, 360)
+	px, py = coordinates[-1]
+	x, y = getPositionFromOffset(px, py, angle, radius)
+	xSum += x
+	ySum += y
+	coordinates.append((x,y))
+
+center = (float(xSum) / n, float(ySum) / n)
+
+cx, cy = center
+coordinates.append((cx-15,cy))
+xOffset = 40
+cTmp = []
+for p in coordinates:
+	px, py = p
+	cTmp.append((px-cx+xOffset,py-cy))	
+
+coordinates = cTmp
+cx, cy = xOffset, 0
+pointCoords = ""
+
+for p in coordinates:
+	px, py = p	
+	newP = "(%.2f,%.2f)," % (px, py)
+	pointCoords = newP + pointCoords
+	deltaY = -py
+	deltaX = xOffset-px
+	length = (deltaY**2+deltaX**2)**0.5
+	sinAlpha = deltaY/length
+	cosAlpha = deltaX/length
+	print("\draw[->] (%.2f,%.2f) -- (%.2f,%.2f);" % (px, py, px+cosAlpha*length*0.80, py+sinAlpha*length*0.80))
+
+
+print("\\node[circle,inner sep=1pt,fill]  at (%.2f,%.2f) {};" % (xOffset, 0))
+
+print("\\foreach \point in {" + pointCoords[:-1] + "}{")
+print("\\node[dot] at \point {};")
+print("}")
+
+##################################
+
+print("\\node[circle,inner sep=1pt,fill]  at (%.2f,%.2f) {};" % (xOffset, 0))
+
+print("\\foreach \point in {(15,0), (35,0)}{")
+print("\\node[dot] at \point {};")
+print("}")
+
+
+print """
+\end{tikzpicture}
+\end{preview}
+\end{document}
+"""

tikz/center/Makefile

@@ -0,0 +1,35 @@
+SOURCE = center
+DELAY = 80
+DENSITY = 300
+WIDTH = 512
+
+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:
+	make
+	#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
+	rsvg-convert -a -w $(WIDTH) -f svg $(SOURCE).svg -o $(SOURCE)2.svg
+	inkscape $(SOURCE)2.svg --export-plain-svg=$(SOURCE).svg
+	rm $(SOURCE)2.svg

tikz/center/center.tex

@@ -0,0 +1,29 @@
+\documentclass{article}
+\usepackage[pdftex,active,tightpage]{preview}
+\setlength\PreviewBorder{2mm}
+\usepackage{tikz}
+\usepackage{tkz-fct}
+\usetikzlibrary{shapes.misc}
+\usetikzlibrary{shapes, calc, shapes,snakes} 
+\usepackage{amsmath,amssymb}
+
+\begin{document}
+\begin{preview}
+\begin{tikzpicture}[dot/.style={    thick,
+    draw=gray,
+    cross out,
+    inner sep=0pt,
+    minimum width=4pt,
+    minimum height=4pt}]
+\draw[->] (3.20,0.13) -- (3.01,0.86);
+\draw[->] (1.38,1.12) -- (2.65,1.06);
+\draw[->] (3.68,3.38) -- (3.11,1.51);
+\draw[->] (4.46,0.43) -- (3.26,0.92);
+\draw[->] (2.11,0.15) -- (2.79,0.86);
+\node[circle,inner sep=1pt,fill]  at (2.97,1.04) {};
+\foreach \point in {(2.11,0.15),(4.46,0.43),(3.68,3.38),(1.38,1.12),(3.20,0.13)}{
+\node[dot] at \point {};
+}
+\end{tikzpicture}
+\end{preview}
+\end{document}

tikz/center/tikz.py

@@ -0,0 +1,40 @@
+from random import uniform
+import random
+import math
+
+n = 5
+xMin, yMin = 0, 0
+xMax, yMax = 5, 5
+xSum = 0
+ySum = 0
+coordinates = []
+
+random.seed(42)
+
+for i in range(n):
+	x = uniform(xMin, xMax)
+	y = uniform(yMin, yMax)
+	xSum += x
+	ySum += y
+	coordinates.append((x,y))
+
+center = (float(xSum) / n, float(ySum) / n)
+
+cx, cy = center
+pointCoords = ""
+for p in coordinates:
+	px, py = p	
+	newP = "(%.2f,%.2f)," % (px, py)
+	pointCoords = newP + pointCoords
+	deltaY = cy-py
+	deltaX = cx-px
+	length = (deltaY**2+deltaX**2)**0.5
+	sinAlpha = deltaY/length
+	cosAlpha = deltaX/length
+	print("\draw[->] (%.2f,%.2f) -- (%.2f,%.2f);" % (px, py, px+cosAlpha*length*0.80, py+sinAlpha*length*0.80))
+
+print("\\node[circle,inner sep=1pt,fill]  at (%.2f,%.2f) {};" % (cx, cy))
+
+print("\\foreach \point in {" + pointCoords + "}{")
+print("\\node[dot] at \point {};")
+print("}")