--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/minors.m	Wed Feb 03 17:41:46 2016 +0100
@@ -0,0 +1,31 @@
+function [minor, sub] = minors(A)
+    [n, m] = size(A);
+
+    if n ~= m
+        error('A must be square');
+    end
+
+    sub = {};
+    ks = {};
+
+    ind = 1:n;
+    for k = 1:n
+        C = nchoosek(ind,k);
+        for i = 1:size(C,1)
+            ks{end + 1} = k;
+            sub{end + 1} = A(C(i,:),C(i,:));
+        end
+    end
+
+    for i = 1:length(sub)
+        fprintf('%d:\n', ks{i});
+        disp(sub{i})
+
+        minor(i) = det(sub{i});
+    end
+end
+
+
+% A is positive semidefinite if all minors are non-negative
+% A is negative semidefinite if all odd minors are non-positive and all even minors are non-negative
+