September 2017 Update

Task/Vector-products/Jq/vector-products-1.jq

@@ -0,0 +1,21 @@
+def dot_product(a; b):
+  reduce range(0;a|length) as $i (0; . + (a[$i] * b[$i]) );
+
+# for 3d vectors
+def cross_product(a;b):
+  [ a[1]*b[2] - a[2]*b[1], a[2]*b[0] - a[0]*b[2], a[0]*b[1]-a[1]*b[0] ];
+
+def scalar_triple_product(a;b;c):
+  dot_product(a; cross_product(b; c));
+
+def vector_triple_product(a;b;c):
+  cross_product(a; cross_product(b; c));
+
+def main:
+  [3, 4, 5] as $a
+  | [4, 3, 5] as $b
+  | [-5, -12, -13] as $c
+  | "a . b = \(dot_product($a; $b))",
+    "a x b = [\( cross_product($a; $b) | map(tostring) | join (", ") )]" ,
+    "a . (b x c) = \( scalar_triple_product ($a; $b; $c)) )",
+    "a x (b x c) = [\( vector_triple_product($a; $b; $c)|map(tostring)|join (", ") )]" ;

Task/Vector-products/Jq/vector-products-2.jq

@@ -0,0 +1,4 @@
+"a . b = 49"
+"a x b = [5, 5, -7]"
+"a . (b x c) = 6 )"
+"a x (b x c) = [-267, 204, -3]"