add 87 3d plot in ruby

87 3-D Plot/ruby/3dplot.rb

@@ -0,0 +1,28 @@
+def intro
+  puts "                                3D PLOT
+               CREATIVE COMPUTING  MORRISTOWN, NEW JERSEY\n\n\n\n\n"
+end
+
+def fna(z) = 30 * Math.exp(-z * z / 100)
+
+def render
+  (-30..30).step(1.5).each do |x|
+    l = 0
+    y1 = 5 * (Math.sqrt(900 - x * x) / 5).to_i
+    y_plot = " " * 80
+    (y1..-y1).step(-5).each do |y|
+      z = (25 + fna(Math.sqrt(x * x + y * y)) - 0.7 * y).to_i
+      next if z <= l
+      l = z
+      y_plot[z] = '*'
+    end
+    puts y_plot
+  end
+end
+
+def main
+  intro
+  render
+end
+
+main