Теорема Симсона

Погребицкий Евгений/simson.rkt

@@ -0,0 +1,38 @@
+#lang racket/base
+
+(define (square x) (* x x))
+
+(define (lengths_eq x1 y1 x2 y2 x3 y3)
+(if (equal? (+ (square(- x1 x2)) (square(- y1 y2))) (+ (square(- x3 x1)) (square(- y3 y1)))) 
+#t #f
+))
+
+(define (collinear x1 y1 x2 y2 x3 y3)
+(if (equal? (* (- x1 x2) (- y2 y3)) (* (- y1 y2) (- x2 x3))) 
+#t #f
+))
+
+(define (perpendicular x1 y1 x2 y2 x3 y3 x4 y4)
+(if (equal? (+ (* (- x1 x2) (- x3 x4)) (* (- y1 y2) (- y3 y4))) 0 ) 
+#t #f
+))
+
+
+
+(define (simson o_x o_y a_x a_y b_x b_y c_x c_y d_x d_y e_x e_y f_x f_y g_x g_y)
+(if (and 
+    (lengths_eq o_x o_y a_x a_y b_x b_y) 
+    (lengths_eq o_x o_y a_x a_y c_x c_y) 
+    (lengths_eq o_x o_y a_x a_y d_x d_y) 
+    (collinear e_x e_y b_x b_y c_x c_y)
+    (collinear f_x f_y a_x a_y c_x c_y)
+    (collinear g_x g_y a_x a_y b_x b_y)
+    (perpendicular b_x b_y c_x c_y d_x d_y e_x e_y)
+    (perpendicular a_x a_y c_x c_y d_x d_y f_x f_y)
+    (perpendicular a_x a_y b_x b_y d_x d_y g_x g_y))
+    
+    (begin (displayln "3 Points lie on one line.") (collinear e_x e_y f_x f_y g_x g_y)
+    ) (displayln "3 Points do not lie on one line.")
+))
+
+(simson 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 )