private void addValueBtn_Click(object sender, RoutedEventArgs e)
        {
            string name = addValueNameTextBox.Text.Trim();
            string valueAsString = addValueValueTextBox.Text.Trim();
            double valueAsDouble = Convert.ToDouble(valueAsString);

            NameValuePair nvp = new NameValuePair(name, valueAsDouble);
            dataPoints.Add(nvp);

            addValueNameTextBox.Text = "";
            addValueValueTextBox.Text = "";
        }