add geometry functions to translate and rotate lists and define lines and cubic lines

add data function to fold a list and geometry_plot functions to plot lines and tests for the geometry functions

tests/test_fit.py

@@ -24,11 +24,11 @@ class TestFit(unittest.TestCase):
     """test function"""
     file_name = "test_fit.dat"
     x, y = data_read(file_name, 3, 2)
-    
-    subplot(2,2,1)
+
+    subplot(2, 2, 1)
     plot(x, y, '.-')
-    
-    subplot(2,2,2)
+
+    subplot(2, 2, 2)
     dx = x[1] - x[0]
     dydx = gradient(y, dx)  # central differences
     x_fit = linspace(x[0], x[-1], 150 if len(x) < 50 else len(x)*3)
@@ -36,16 +36,16 @@ class TestFit(unittest.TestCase):
     plot(x, dydx, '.-')
     plot(x_fit, y_fit, 'r:')
     title('FWHM: %f' % FWHM)
-    
-    subplot(2,2,3)
+
+    subplot(2, 2, 3)
     plot(x, y, '.-')
     xlim(popt[1]-2*FWHM, popt[1]+2*FWHM)
-    
-    subplot(2,2,4)
+
+    subplot(2, 2, 4)
     plot(x, dydx, '.-')
     plot(x_fit, y_fit, 'r:')
     xlim(popt[1]-2*FWHM, popt[1]+2*FWHM)
-    
+
     show()
     self.assertEqual(FWHM, 0.12975107355013618)