September 2017 Update

Task/Vector-products/Ring/vector-products.ring

@@ -0,0 +1,35 @@
+# Project : Vector products
+# Date    : 2017/09/21
+# Author  : Gal Zsolt (~ CalmoSoft ~)
+# Email   : <calmosoft@gmail.com>
+
+d = list(3)
+e = list(3)
+a = [3, 4, 5]
+b = [4, 3, 5]
+c = [-5, -12, -13]
+
+see "a . b = " + dot(a,b) + nl
+cross(a,b,d)
+see "a x b = (" + d[1] + ", " + d[2] + ", " + d[3] + ")" + nl
+see "a . (b x c) = " + scalartriple(a,b,c) + nl
+vectortriple(a,b,c,d)
+
+def dot(a,b)
+    sum = 0
+    for n=1 to len(a)
+        sum = sum + a[n]*b[n]
+    next
+    return sum
+
+func cross(a,b,d)
+     d = [a[2]*b[3]-a[3]*b[2], a[3]*b[1]-a[1]*b[3], a[1]*b[2]-a[2]*b[1]]
+
+func scalartriple(a,b,c)
+     cross(b,c,d)
+     return dot(a,d)
+
+func vectortriple(a,b,c,d)
+     cross(b,c,d)
+     cross(a,d,e)
+     see "a x (b x c) = (" + e[1] + ", " +e[2] + ", " + e[3] + ")"