Initial MoonModel implementation

test/data_set_test.rb

@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+require "test_helper"
+
+class DataSetTest < Minitest::Test
+  def test_reads_and_wraps_data
+    Dir.mktmpdir do |dir|
+      data = MoonModel::DataSet.new(make_data(File.join(dir, "data.gz")))
+      assert_equal 16, data.width
+      assert_in_delta data.reflectance(0, 0), data.reflectance(0, 360), 1e-9
+      assert_in_delta 300, data.relief_range_m, 1e-9
+    end
+  end
+end