1 files changed, 26 insertions, 0 deletions
diff --git a/plotter/view/puzzletree/nodes/sine.py b/plotter/view/puzzletree/nodes/sine.py
new file mode 100755
index 0000000..493354e
--- /dev/null
+++ b/plotter/view/puzzletree/nodes/sine.py
@@ -0,0 +1,26 @@
+
+from .simplenode import SimpleNode
+from gettext import gettext as _
+
+import math
+
+
+class Sine(SimpleNode):
+    """Node representing the sine function: f(x) = sin(x)."""
+
+    CLASS = "sine"
+    background = SimpleNode.loadbackground("sine.svg")
+    title = _("Sine")
+    description = _(u"Returns the ratio of the length of a side opposite an "
+        u"acute angle in a right trianale to the length of the hypotenuse.\n"
+        u"For example, sin(pi / 4) = 1 / sqrt(2)")
+
+    def __call__(self, x):
+        """Calls the sine function."""
+        return math.sin(x)
+
+
+    def get_equation_string(self, variable):
+        """Returns sin(x) given x."""
+        return "sin(%s)" % variable
+