setUpRandom

docs/00_index.md

@@ -193,7 +193,7 @@ let PTB find and use the default device.
 ## 3. <a name='functionsdescriptions'></a>functions descriptions
 
 The main functions of the toolbox are described
-[here](./10_functions_descriptions.md).
+[here](./10_functions_description.md).
 
 ## 4. <a name='Annexes'></a>Annexes
 

docs/10_functions_description.md

@@ -26,6 +26,7 @@
     -   6.1. [shuffle](#shuffle)
     -   6.2. [setTargetPositionInSequence](#setTargetPositionInSequence)
     -   6.3. [repeatShuffleConditions](#repeatShuffleConditions)
+    -   6.4. [setUpRand](#setUprand)
 
 <!-- vscode-markdown-toc-config
 	numbering=true
@@ -214,3 +215,8 @@ they are not in consecutive positions.
 Given `baseConditionVector`, a vector of conditions (coded as numbers), this
 will create a longer vector made of `nbRepeats` of this base vector and make
 sure that a given condition is not repeated one after the other.
+
+### 6.4. <a name='setUpRand'></a>setUpRand
+
+Resets the seed of the random number generator. Will "adapt" depending on the matlab/octave version.
+ It is of great importance to do this before anything else!

src/utils/setUpRand.m

@@ -0,0 +1,42 @@
+% (C) Copyright 2010-2020 Sam Schwarzkopf
+% (C) Copyright 2020 CPP_PTB developers
+
+function setUpRand()
+    % setUpRand()
+    %
+    % Resets the seed of the random number generator. Will "adapt" depending on the matlab/octave
+    % version.
+    % It is of great importance to do this before anything else!
+    %
+    % For an alternative from PTB see `ClockRandSeed`
+
+    seed = sum(100 * clock);
+
+    try
+        % Use the reccomended method in modern Matlab
+        RandStream.setGlobalStream(RandStream('mt19937ar', 'seed', seed));
+        disp('Using modern randomizer...');
+    catch
+
+        try
+            % Use the recommended method in Matlab R2012a.
+            rng('shuffle');
+            disp('Using less modern randomizer...');
+        catch
+
+            try
+                % Use worse methods for Octave or old versions of Matlab (e.g. 7.1.0.246 (R14) SP3).
+                rand('twister', seed);
+                randn('twister', seed);
+                disp('Using Octave or outdated randomizer...');
+            catch
+                % For very old Matlab versions these are the only methods you can use.
+                % These are supposed to be flawed although you will probably not
+                % notice any effect of this for most situations.
+                rand('state', seed);
+                randn('state', seed);
+                disp('Using "flawed" randomizer...');
+            end
+        end
+
+    end