Added tests for some geometry functions.

Author: rexim

src/hyperspace/geometry.clj

@@ -25,6 +25,8 @@
   (Math/sqrt (reduce #(+ %1 (* %2 %2)) 0.0 vtr)))
 
 (defn normilize-vector
+  "Normilizes vector, that is returns a vector with the same
+  direction, but with the length equal 1."
   [vtr]
   (let [length (vector-length vtr)]
     (mapv #(/ % length) vtr)))

test/hyperspace/test/geometry.clj

@@ -4,15 +4,38 @@
         [midje.sweet]))
 
 (fact "about vector-sum function"
-      ;; One-dimensional integer vectors
-      (vector-sum [2] [2])               => [4]
-      
-      ;; Two-dimensional integer vectors
-      (vector-sum [5, 5] [2, 3])         => [7, 8]
-      
-      ;; Tree-dimenstional integer vectors
-      (vector-sum [1, 2, 3] [4, 5, 6])   => [5, 7, 9]
-
-      ;; Floating point vectors
+      (vector-sum [2] [2]) => [4]
+      (vector-sum [5, 5] [2, 3]) => [7, 8]
+      (vector-sum [1, 2, 3] [4, 5, 6]) => [5, 7, 9]
       (vector-sum [0.2, 0.4] [0.1, 0.3]) => (just [(almost= 0.3)
-                                                   (almost= 0.7)]))
+                                                   (almost= 0.7)])
+      (vector-sum [12, 62]) => [12, 62]
+      (vector-sum [1, 2] [3, 4] [5, 6] [7, 8]) => [16, 20])
+
+(fact "about vector-subtract function"
+      (vector-subtract [3] [2]) => [1]
+      (vector-subtract [3, 2] [2, 1]) => [1, 1]
+      (vector-subtract [4, 5, 6] [6, 5, 4]) => [-2, 0, 2]
+      (vector-subtract [0.4 0.2] [0.3 0.2]) => (just [(almost= 0.1)
+                                                      (almost= 0.0)])
+      (vector-subtract [4, 6]) => [-4, -6]
+      (vector-subtract [100, 100] [2, 5] [5, 2] [9, 3]) => [84, 90])
+
+(fact "about multiply-by-scalar function"
+      (multiply-by-scalar [2] 10) => [20]
+      (multiply-by-scalar [1, 2] 2) => [2, 4]
+      (multiply-by-scalar [5, 2, 1] 5) => [25, 10, 5]
+      (multiply-by-scalar [0.2, 0.5] 3) => (just [(almost= 0.6),
+                                                  (almost= 1.5)]))
+
+(fact "about vector-length function"
+      (vector-length [7]) => (almost= 7)
+      (vector-length [10, 10]) => (almost= 14.142135623730951)
+      (vector-length [34, 123, 431]) => (almost= 449.4952725001677)
+      (vector-length [1.23, 10.32]) => (almost= 10.393040940937354))
+
+(fact "about normilize-vector function"
+      (vector-length (normilize-vector [7])) => (almost= 1.0)
+      (vector-length (normilize-vector [10, 10])) => (almost= 1.0)
+      (vector-length (normilize-vector [34, 123, 431])) => (almost= 1.0)
+      (vector-length (normilize-vector [1.23, 10.32])) => (almost= 1.0))