Boolean and logical indexing done

programming/code/logicalIndexingBenchmark.m

@@ -0,0 +1,21 @@
+% create a vector with a random numbers
+x = rand(1000000, 1);
+
+fprintf('time needed to manually filter elements smaller than 0.5 in a vector of length %i\n', length(x))
+
+tic
+results = [];
+matches = 1;
+for i = 1:length(x)
+    if x(i) < 0.5
+        results(matches) = x(i);
+        matches = matches + 1;
+    end
+end
+toc
+
+fprintf('\ntime needed to do the same with logical indexing\n')
+
+tic
+results = x(x < 0.5);
+toc

programming/code/logicalIndexingTime.m

@@ -0,0 +1,12 @@
+t = 0:0.001:10;
+x = randn(size(t));
+selection = x (t > 5 & t < 6);
+
+figure()
+hold on
+plot(t, x, 'displayname', 'measurements')
+plot(t(t > 5 & t < 6), selection, 'displayname', 'selection')
+xlabel('time [s]')
+ylabel('intensity')
+legend 'show'
+box 'off'

programming/code/logicalVector.m

@@ -0,0 +1,12 @@
+x = 1:10;
+
+%% Erstellen eines logischen Vektors
+y = x < 5;
+fprintf('Logischer Vektor y:\n');
+y
+fprintf('Datentyp von y: %s\n', class(y));
+
+%% Auswahl aller Element, die kleiner 5 sind
+fprintf('\nAlle Elemente aus x, die kleiner als 5 sind:\n')
+
+x(y)

programming/code/vectorsize.m

@@ -0,0 +1,9 @@
+a = (11:20); % a vector with 10 Elements
+fprintf('length of a: %i\n', length(a))
+size_of_a = size(a); % get the size and store it in a new variable
+
+% size_of_a is a vector itself
+fprintf('number of dimensions (rank) of size_of_a: %i\n', length(size_of_a))
+
+% get the value of the second element of size_of_a
+fprintf('number of entries in the 2nd dimesion of a: %i\n', size_of_a(2))