From 4aa6200c8c18b9bb70e97d07e6d846d392459cd0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Andreas=20M=C3=BCller?= <andreas.mueller@ost.ch>
Date: Thu, 27 May 2021 09:49:53 +0200
Subject: laplace basis slides

---
 vorlesungen/slides/8/wavelets/ev.m | 97 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 97 insertions(+)
 create mode 100644 vorlesungen/slides/8/wavelets/ev.m

(limited to 'vorlesungen/slides/8/wavelets/ev.m')

diff --git a/vorlesungen/slides/8/wavelets/ev.m b/vorlesungen/slides/8/wavelets/ev.m
new file mode 100644
index 0000000..7f4dd55
--- /dev/null
+++ b/vorlesungen/slides/8/wavelets/ev.m
@@ -0,0 +1,97 @@
+#
+# ev.m
+#
+# (c) 2021 Prof Dr Andreas Müller, OST Ostschweizer Fachhochschule
+#
+
+L = [
+    2, -1,  0, -1,  0;
+   -1,  4, -1, -1, -1;
+    0, -1,  2,  0, -1;
+   -1, -1,  0,  3, -1;
+    0, -1, -1, -1,  3
+];
+
+[v, lambda] = eig(L);
+
+function knoten(fn, wert, punkt)
+	if (wert > 0) 
+		farbe = sprintf("red!%02d", round(100 * wert));
+	else
+		farbe = sprintf("blue!%02d", round(-100 * wert));
+	end
+	fprintf(fn, "\t\\fill[color=%s] %s circle[radius=0.25];\n",
+		farbe, punkt);
+	fprintf(fn, "\t\\draw %s circle[radius=0.25];\n", punkt);
+endfunction
+
+function vektor(fn, v, name, lambda)
+	fprintf(fn, "\\def\\%s{\n", name);
+	fprintf(fn, "\t\\coordinate (A) at ({0*\\a},0);\n");
+	fprintf(fn, "\t\\coordinate (B) at ({1*\\a},0);\n");
+	fprintf(fn, "\t\\coordinate (C) at ({2*\\a},0);\n");
+	fprintf(fn, "\t\\coordinate (D) at ({0.5*\\a},{-\\b});\n");
+	fprintf(fn, "\t\\coordinate (E) at ({1.5*\\a},{-\\b});\n");
+	fprintf(fn, "\t\\draw (A) -- (B);\n");
+	fprintf(fn, "\t\\draw (A) -- (D);\n");
+	fprintf(fn, "\t\\draw (B) -- (C);\n");
+	fprintf(fn, "\t\\draw (B) -- (D);\n");
+	fprintf(fn, "\t\\draw (B) -- (E);\n");
+	fprintf(fn, "\t\\draw (C) -- (E);\n");
+	fprintf(fn, "\t\\draw (D) -- (E);\n");
+	fprintf(fn, "\t\\node at (-2.8,{-0.5*\\b}) [right] {$\\lambda=%.4f$};\n",
+		round(1000 * abs(lambda)) / 10000);
+	w = v / max(abs(v));
+	knoten(fn, w(1,1), "(A)");
+	knoten(fn, w(2,1), "(B)");
+	knoten(fn, w(3,1), "(C)");
+	knoten(fn, w(4,1), "(D)");
+	knoten(fn, w(5,1), "(E)");
+	fprintf(fn, "}\n");
+endfunction
+
+function punkt(fn, x, wert)
+	fprintf(fn, "({%.4f*\\c},{%.4f*\\d})", x, wert);
+endfunction
+
+function funktion(fn, v, name, lambda)
+	fprintf(fn, "\\def\\%s{\n", name);
+	fprintf(fn, "\t\\draw[color=red,line width=1.4pt]\n\t\t");
+	punkt(fn, -2, v(1,1));
+	fprintf(fn, " --\n\t\t");
+	punkt(fn, -1, v(4,1));
+	fprintf(fn, " --\n\t\t");
+	punkt(fn, 0, v(2,1));
+	fprintf(fn, " --\n\t\t");
+	punkt(fn, 1, v(5,1));
+	fprintf(fn, " --\n\t\t");
+	punkt(fn, 2, v(3,1));
+	fprintf(fn, ";\n");
+	fprintf(fn, "\t\\draw[->] ({-2.1*\\c},0) -- ({2.1*\\c},0);\n");
+	fprintf(fn, "\t\\draw[->] (0,{-1.1*\\d}) -- (0,{1.1*\\d});\n");
+	for x = (-2:2)
+		fprintf(fn, "\t\\fill ({%d*\\c},0) circle[radius=0.05];\n", x);
+	endfor
+	fprintf(fn, "}\n");
+endfunction
+
+fn = fopen("vektoren.tex", "w");
+
+vektor(fn, v(:,1), "vnull", lambda(1,1));
+funktion(fn, v(:,1), "fnull", lambda(1,1));
+
+vektor(fn, v(:,2), "vone", lambda(2,2));
+funktion(fn, v(:,2), "fone", lambda(2,2));
+
+vektor(fn, v(:,3), "vtwo", lambda(3,3));
+funktion(fn, v(:,3), "ftwo", lambda(3,3));
+
+vektor(fn, v(:,4), "vthree", lambda(4,4));
+funktion(fn, v(:,4), "fthree", lambda(4,4));
+
+vektor(fn, v(:,5), "vfour", lambda(5,5));
+funktion(fn, v(:,5), "ffour", lambda(5,5));
+
+fclose(fn);
+
+
-- 
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