diff options
Diffstat (limited to 'src/python/example')
16 files changed, 329 insertions, 34 deletions
diff --git a/src/python/example/alpha_complex_diagram_persistence_from_off_file_example.py b/src/python/example/alpha_complex_diagram_persistence_from_off_file_example.py index b8f283b3..4079a469 100755 --- a/src/python/example/alpha_complex_diagram_persistence_from_off_file_example.py +++ b/src/python/example/alpha_complex_diagram_persistence_from_off_file_example.py @@ -1,7 +1,8 @@ #!/usr/bin/env python -import gudhi import argparse +import matplotlib.pyplot as plot +import gudhi """ This file is part of the Gudhi Library - https://gudhi.inria.fr/ - which is released under MIT. See file LICENSE or go to https://gudhi.inria.fr/licensing/ for full license details. @@ -60,8 +61,8 @@ with open(args.file, "r") as f: print(simplex_tree.betti_numbers()) if args.no_diagram == False: - pplot = gudhi.plot_persistence_diagram(diag, band=args.band) - pplot.show() + gudhi.plot_persistence_diagram(diag, band=args.band) + plot.show() else: print(args.file, "is not a valid OFF file") diff --git a/src/python/example/alpha_rips_persistence_bottleneck_distance.py b/src/python/example/alpha_rips_persistence_bottleneck_distance.py index 086307ee..d5c33ec8 100755 --- a/src/python/example/alpha_rips_persistence_bottleneck_distance.py +++ b/src/python/example/alpha_rips_persistence_bottleneck_distance.py @@ -35,7 +35,7 @@ args = parser.parse_args() with open(args.file, "r") as f: first_line = f.readline() if (first_line == "OFF\n") or (first_line == "nOFF\n"): - point_cloud = gudhi.read_off(off_file=args.file) + point_cloud = gudhi.read_points_from_off_file(off_file=args.file) print("#####################################################################") print("RipsComplex creation from points read in a OFF file") diff --git a/src/python/example/diagram_vectorizations_distances_kernels.py b/src/python/example/diagram_vectorizations_distances_kernels.py new file mode 100755 index 00000000..119072eb --- /dev/null +++ b/src/python/example/diagram_vectorizations_distances_kernels.py @@ -0,0 +1,133 @@ +#!/usr/bin/env python + +import matplotlib.pyplot as plt +import numpy as np +from sklearn.kernel_approximation import RBFSampler +from sklearn.preprocessing import MinMaxScaler + +from gudhi.representations import DiagramSelector, Clamping, Landscape, Silhouette, BettiCurve, ComplexPolynomial,\ + TopologicalVector, DiagramScaler, BirthPersistenceTransform,\ + PersistenceImage, PersistenceWeightedGaussianKernel, Entropy, \ + PersistenceScaleSpaceKernel, SlicedWassersteinDistance,\ + SlicedWassersteinKernel, BottleneckDistance, PersistenceFisherKernel + +D = np.array([[0.,4.],[1.,2.],[3.,8.],[6.,8.], [0., np.inf], [5., np.inf]]) +diags = [D] + +diags = DiagramSelector(use=True, point_type="finite").fit_transform(diags) +diags = DiagramScaler(use=True, scalers=[([0,1], MinMaxScaler())]).fit_transform(diags) +diags = DiagramScaler(use=True, scalers=[([1], Clamping(maximum=.9))]).fit_transform(diags) + +D = diags[0] +plt.scatter(D[:,0],D[:,1]) +plt.plot([0.,1.],[0.,1.]) +plt.title("Test Persistence Diagram for vector methods") +plt.show() + +LS = Landscape(resolution=1000) +L = LS.fit_transform(diags) +plt.plot(L[0][:1000]) +plt.plot(L[0][1000:2000]) +plt.plot(L[0][2000:3000]) +plt.title("Landscape") +plt.show() + +def pow(n): + return lambda x: np.power(x[1]-x[0],n) + +SH = Silhouette(resolution=1000, weight=pow(2)) +sh = SH.fit_transform(diags) +plt.plot(sh[0]) +plt.title("Silhouette") +plt.show() + +BC = BettiCurve(resolution=1000) +bc = BC.fit_transform(diags) +plt.plot(bc[0]) +plt.title("Betti Curve") +plt.show() + +CP = ComplexPolynomial(threshold=-1, polynomial_type="T") +cp = CP.fit_transform(diags) +print("Complex polynomial is " + str(cp[0,:])) + +TV = TopologicalVector(threshold=-1) +tv = TV.fit_transform(diags) +print("Topological vector is " + str(tv[0,:])) + +PI = PersistenceImage(bandwidth=.1, weight=lambda x: x[1], im_range=[0,1,0,1], resolution=[100,100]) +pi = PI.fit_transform(diags) +plt.imshow(np.flip(np.reshape(pi[0], [100,100]), 0)) +plt.title("Persistence Image") +plt.show() + +ET = Entropy(mode="scalar") +et = ET.fit_transform(diags) +print("Entropy statistic is " + str(et[0,:])) + +ET = Entropy(mode="vector", normalized=False) +et = ET.fit_transform(diags) +plt.plot(et[0]) +plt.title("Entropy function") +plt.show() + +D = np.array([[1.,5.],[3.,6.],[2.,7.]]) +diags2 = [D] + +diags2 = DiagramScaler(use=True, scalers=[([0,1], MinMaxScaler())]).fit_transform(diags2) + +D = diags[0] +plt.scatter(D[:,0],D[:,1]) +D = diags2[0] +plt.scatter(D[:,0],D[:,1]) +plt.plot([0.,1.],[0.,1.]) +plt.title("Test Persistence Diagrams for kernel methods") +plt.show() + +def arctan(C,p): + return lambda x: C*np.arctan(np.power(x[1], p)) + +PWG = PersistenceWeightedGaussianKernel(bandwidth=1., kernel_approx=None, weight=arctan(1.,1.)) +X = PWG.fit(diags) +Y = PWG.transform(diags2) +print("PWG kernel is " + str(Y[0][0])) + +PWG = PersistenceWeightedGaussianKernel(kernel_approx=RBFSampler(gamma=1./2, n_components=100000).fit(np.ones([1,2])), weight=arctan(1.,1.)) +X = PWG.fit(diags) +Y = PWG.transform(diags2) +print("Approximate PWG kernel is " + str(Y[0][0])) + +PSS = PersistenceScaleSpaceKernel(bandwidth=1.) +X = PSS.fit(diags) +Y = PSS.transform(diags2) +print("PSS kernel is " + str(Y[0][0])) + +PSS = PersistenceScaleSpaceKernel(kernel_approx=RBFSampler(gamma=1./2, n_components=100000).fit(np.ones([1,2]))) +X = PSS.fit(diags) +Y = PSS.transform(diags2) +print("Approximate PSS kernel is " + str(Y[0][0])) + +sW = SlicedWassersteinDistance(num_directions=100) +X = sW.fit(diags) +Y = sW.transform(diags2) +print("SW distance is " + str(Y[0][0])) + +SW = SlicedWassersteinKernel(num_directions=100, bandwidth=1.) +X = SW.fit(diags) +Y = SW.transform(diags2) +print("SW kernel is " + str(Y[0][0])) + +W = BottleneckDistance(epsilon=.001) +X = W.fit(diags) +Y = W.transform(diags2) +print("Bottleneck distance is " + str(Y[0][0])) + +PF = PersistenceFisherKernel(bandwidth_fisher=1., bandwidth=1.) +X = PF.fit(diags) +Y = PF.transform(diags2) +print("PF kernel is " + str(Y[0][0])) + +PF = PersistenceFisherKernel(bandwidth_fisher=1., bandwidth=1., kernel_approx=RBFSampler(gamma=1./2, n_components=100000).fit(np.ones([1,2]))) +X = PF.fit(diags) +Y = PF.transform(diags2) +print("Approximate PF kernel is " + str(Y[0][0])) diff --git a/src/python/example/euclidean_strong_witness_complex_diagram_persistence_from_off_file_example.py b/src/python/example/euclidean_strong_witness_complex_diagram_persistence_from_off_file_example.py index 610ba44f..4903667e 100755 --- a/src/python/example/euclidean_strong_witness_complex_diagram_persistence_from_off_file_example.py +++ b/src/python/example/euclidean_strong_witness_complex_diagram_persistence_from_off_file_example.py @@ -1,7 +1,8 @@ #!/usr/bin/env python -import gudhi import argparse +import matplotlib.pyplot as plot +import gudhi """ This file is part of the Gudhi Library - https://gudhi.inria.fr/ - which is released under MIT. See file LICENSE or go to https://gudhi.inria.fr/licensing/ for full license details. @@ -46,7 +47,7 @@ with open(args.file, "r") as f: print("#####################################################################") print("EuclideanStrongWitnessComplex creation from points read in a OFF file") - witnesses = gudhi.read_off(off_file=args.file) + witnesses = gudhi.read_points_from_off_file(off_file=args.file) landmarks = gudhi.pick_n_random_points( points=witnesses, nb_points=args.number_of_landmarks ) @@ -75,8 +76,8 @@ with open(args.file, "r") as f: print(simplex_tree.betti_numbers()) if args.no_diagram == False: - pplot = gudhi.plot_persistence_diagram(diag, band=args.band) - pplot.show() + gudhi.plot_persistence_diagram(diag, band=args.band) + plot.show() else: print(args.file, "is not a valid OFF file") diff --git a/src/python/example/euclidean_witness_complex_diagram_persistence_from_off_file_example.py b/src/python/example/euclidean_witness_complex_diagram_persistence_from_off_file_example.py index 7587b732..339a8577 100755 --- a/src/python/example/euclidean_witness_complex_diagram_persistence_from_off_file_example.py +++ b/src/python/example/euclidean_witness_complex_diagram_persistence_from_off_file_example.py @@ -1,7 +1,8 @@ #!/usr/bin/env python -import gudhi import argparse +import matplotlib.pyplot as plot +import gudhi """ This file is part of the Gudhi Library - https://gudhi.inria.fr/ - which is released under MIT. See file LICENSE or go to https://gudhi.inria.fr/licensing/ for full license details. @@ -45,7 +46,7 @@ with open(args.file, "r") as f: print("#####################################################################") print("EuclideanWitnessComplex creation from points read in a OFF file") - witnesses = gudhi.read_off(off_file=args.file) + witnesses = gudhi.read_points_from_off_file(off_file=args.file) landmarks = gudhi.pick_n_random_points( points=witnesses, nb_points=args.number_of_landmarks ) @@ -74,8 +75,8 @@ with open(args.file, "r") as f: print(simplex_tree.betti_numbers()) if args.no_diagram == False: - pplot = gudhi.plot_persistence_diagram(diag, band=args.band) - pplot.show() + gudhi.plot_persistence_diagram(diag, band=args.band) + plot.show() else: print(args.file, "is not a valid OFF file") diff --git a/src/python/example/gudhi_graphical_tools_example.py b/src/python/example/gudhi_graphical_tools_example.py index 3b0ca54d..37ecbf53 100755 --- a/src/python/example/gudhi_graphical_tools_example.py +++ b/src/python/example/gudhi_graphical_tools_example.py @@ -1,5 +1,6 @@ #!/usr/bin/env python +import matplotlib.pyplot as plot import gudhi """ This file is part of the Gudhi Library - https://gudhi.inria.fr/ - which is released under MIT. @@ -29,15 +30,24 @@ persistence = [ (0, (0.0, 1.0)), ] gudhi.plot_persistence_barcode(persistence) +plot.show() print("#####################################################################") print("Show diagram persistence example") -pplot = gudhi.plot_persistence_diagram(persistence) -pplot.show() +gudhi.plot_persistence_diagram(persistence) +plot.show() print("#####################################################################") print("Show diagram persistence example with a confidence band") -pplot = gudhi.plot_persistence_diagram(persistence, band=0.2) -pplot.show() +gudhi.plot_persistence_diagram(persistence, band=0.2) +plot.show() + +print("#####################################################################") +print("Show barcode and diagram persistence side by side example") +fig, axes = plot.subplots(nrows=1, ncols=2) +gudhi.plot_persistence_barcode(persistence, axes = axes[0]) +gudhi.plot_persistence_diagram(persistence, axes = axes[1]) +fig.suptitle("barcode versus diagram") +plot.show() diff --git a/src/python/example/periodic_cubical_complex_barcode_persistence_from_perseus_file_example.py b/src/python/example/periodic_cubical_complex_barcode_persistence_from_perseus_file_example.py index 9cb855cd..c692e66f 100755 --- a/src/python/example/periodic_cubical_complex_barcode_persistence_from_perseus_file_example.py +++ b/src/python/example/periodic_cubical_complex_barcode_persistence_from_perseus_file_example.py @@ -1,7 +1,8 @@ #!/usr/bin/env python -import gudhi import argparse +import matplotlib.pyplot as plot +import gudhi """ This file is part of the Gudhi Library - https://gudhi.inria.fr/ - which is released under MIT. See file LICENSE or go to https://gudhi.inria.fr/licensing/ for full license details. @@ -70,5 +71,6 @@ if is_file_perseus(args.file): print(periodic_cubical_complex.betti_numbers()) if args.no_barcode == False: gudhi.plot_persistence_barcode(diag) + plot.show() else: print(args.file, "is not a valid perseus style file") diff --git a/src/python/example/plot_alpha_complex.py b/src/python/example/plot_alpha_complex.py new file mode 100755 index 00000000..99c18a7c --- /dev/null +++ b/src/python/example/plot_alpha_complex.py @@ -0,0 +1,37 @@ +#!/usr/bin/env python + +import numpy as np +import gudhi +ac = gudhi.AlphaComplex(off_file='../../data/points/tore3D_1307.off') +st = ac.create_simplex_tree() +points = np.array([ac.get_point(i) for i in range(st.num_vertices())]) +# We want to plot the alpha-complex with alpha=0.1. +# We are only going to plot the triangles +triangles = np.array([s[0] for s in st.get_skeleton(2) if len(s[0])==3 and s[1] <= .1]) + +# First possibility: plotly +import plotly.graph_objects as go +fig = go.Figure(data=[ + go.Mesh3d( + x=points[:,0], + y=points[:,1], + z=points[:,2], + i = triangles[:,0], + j = triangles[:,1], + k = triangles[:,2], + ) +]) +fig.show() + +# Second possibility: matplotlib +from mpl_toolkits.mplot3d import Axes3D +import matplotlib.pyplot as plt +fig = plt.figure() +ax = fig.gca(projection='3d') +ax.plot_trisurf(points[:,0], points[:,1], points[:,2], triangles=triangles) +plt.show() + +# Third possibility: mayavi +from mayavi import mlab +mlab.triangular_mesh(points[:,0], points[:,1], points[:,2], triangles); +mlab.show() diff --git a/src/python/example/plot_rips_complex.py b/src/python/example/plot_rips_complex.py new file mode 100755 index 00000000..214a3c0a --- /dev/null +++ b/src/python/example/plot_rips_complex.py @@ -0,0 +1,38 @@ +#!/usr/bin/env python + +import numpy as np +import gudhi +points = np.array(gudhi.read_points_from_off_file('../../data/points/Kl.off')) +rc = gudhi.RipsComplex(points=points, max_edge_length=.2) +st = rc.create_simplex_tree(max_dimension=2) +# We are only going to plot the triangles +triangles = np.array([s[0] for s in st.get_skeleton(2) if len(s[0])==3]) + +# First possibility: plotly +import plotly.graph_objects as go +fig = go.Figure(data=[ + go.Mesh3d( + # Use the first 3 coordinates, but we could as easily pick others + x=points[:,0], + y=points[:,1], + z=points[:,2], + i = triangles[:,0], + j = triangles[:,1], + k = triangles[:,2], + ) +]) +fig.show() + +# Second possibility: matplotlib +from mpl_toolkits.mplot3d import Axes3D +import matplotlib.pyplot as plt +fig = plt.figure() +ax = fig.gca(projection='3d') +ax.plot_trisurf(points[:,0], points[:,1], points[:,2], triangles=triangles) +plt.show() + +# Third possibility: mayavi +# (this may take a while) +from mayavi import mlab +mlab.triangular_mesh(points[:,0], points[:,1], points[:,2], triangles); +mlab.show() diff --git a/src/python/example/plot_simplex_tree_dim012.py b/src/python/example/plot_simplex_tree_dim012.py new file mode 100755 index 00000000..5b962131 --- /dev/null +++ b/src/python/example/plot_simplex_tree_dim012.py @@ -0,0 +1,66 @@ +#!/usr/bin/env python +import numpy as np +import gudhi + +# Coordinates of the points +points=np.array([[0,0,0],[1,0,0],[0,1,0],[0,0,1],[1,1,1],[1,1,0],[0,1,1]]) +# Build the simplicial complex with a tetrahedon, an edge and an isolated vertex +cplx=gudhi.SimplexTree() +cplx.insert([1,2,3,5]) +cplx.insert([4,6]) +cplx.insert([0]) +# List of triangles (point indices) +triangles = np.array([s[0] for s in cplx.get_skeleton(2) if len(s[0])==3]) +# List of edges (point coordinates) +edges = [] +for s in cplx.get_skeleton(1): + e = s[0] + if len(e) == 2: + edges.append(points[[e[0],e[1]]]) + +## With plotly +import plotly.graph_objects as go +# Plot triangles +f2 = go.Mesh3d( + x=points[:,0], + y=points[:,1], + z=points[:,2], + i = triangles[:,0], + j = triangles[:,1], + k = triangles[:,2], + ) +# Plot points +f0 = go.Scatter3d(x=points[:,0], y=points[:,1], z=points[:,2], mode="markers") +data = [f2, f0] +# Plot edges +for pts in edges: + seg = go.Scatter3d(x=pts[:,0],y=pts[:,1],z=pts[:,2],mode="lines",line=dict(color='green')) + data.append(seg) +fig = go.Figure(data=data,layout=dict(showlegend=False)) +# By default plotly would give each edge its own color and legend, that's too much +fig.show() + +## With matplotlib +from mpl_toolkits.mplot3d import Axes3D +from mpl_toolkits.mplot3d.art3d import Line3DCollection +import matplotlib.pyplot as plt +fig = plt.figure() +ax = fig.gca(projection='3d') +# Plot triangles +ax.plot_trisurf(points[:,0], points[:,1], points[:,2], triangles=triangles) +# Plot points +ax.scatter3D(points[:,0], points[:,1], points[:,2]) +# Plot edges +ax.add_collection3d(Line3DCollection(segments=edges)) +plt.show() + +## With mayavi +from mayavi import mlab +# Plot triangles +mlab.triangular_mesh(points[:,0], points[:,1], points[:,2], triangles); +# Plot points +mlab.points3d(points[:,0], points[:,1], points[:,2]) +# Plot edges +for pts in edges: + mlab.plot3d(pts[:,0],pts[:,1],pts[:,2],tube_radius=None) +mlab.show() diff --git a/src/python/example/rips_complex_diagram_persistence_from_correlation_matrix_file_example.py b/src/python/example/rips_complex_diagram_persistence_from_correlation_matrix_file_example.py index 3571580b..1acb187c 100755 --- a/src/python/example/rips_complex_diagram_persistence_from_correlation_matrix_file_example.py +++ b/src/python/example/rips_complex_diagram_persistence_from_correlation_matrix_file_example.py @@ -1,8 +1,9 @@ #!/usr/bin/env python -import gudhi import sys import argparse +import matplotlib.pyplot as plot +import gudhi """ This file is part of the Gudhi Library - https://gudhi.inria.fr/ - which is released under MIT. See file LICENSE or go to https://gudhi.inria.fr/licensing/ for full license details. @@ -83,5 +84,5 @@ invert_diag = [ ] if args.no_diagram == False: - pplot = gudhi.plot_persistence_diagram(invert_diag, band=args.band) - pplot.show() + gudhi.plot_persistence_diagram(invert_diag, band=args.band) + plot.show() diff --git a/src/python/example/rips_complex_diagram_persistence_from_distance_matrix_file_example.py b/src/python/example/rips_complex_diagram_persistence_from_distance_matrix_file_example.py index 0b9a9ba9..79ccca96 100755 --- a/src/python/example/rips_complex_diagram_persistence_from_distance_matrix_file_example.py +++ b/src/python/example/rips_complex_diagram_persistence_from_distance_matrix_file_example.py @@ -1,7 +1,8 @@ #!/usr/bin/env python -import gudhi import argparse +import matplotlib.pyplot as plot +import gudhi """ This file is part of the Gudhi Library - https://gudhi.inria.fr/ - which is released under MIT. See file LICENSE or go to https://gudhi.inria.fr/licensing/ for full license details. @@ -59,5 +60,5 @@ print("betti_numbers()=") print(simplex_tree.betti_numbers()) if args.no_diagram == False: - pplot = gudhi.plot_persistence_diagram(diag, band=args.band) - pplot.show() + gudhi.plot_persistence_diagram(diag, band=args.band) + plot.show() diff --git a/src/python/example/rips_complex_diagram_persistence_from_off_file_example.py b/src/python/example/rips_complex_diagram_persistence_from_off_file_example.py index 2b335bba..c757aca7 100755 --- a/src/python/example/rips_complex_diagram_persistence_from_off_file_example.py +++ b/src/python/example/rips_complex_diagram_persistence_from_off_file_example.py @@ -1,7 +1,8 @@ #!/usr/bin/env python -import gudhi import argparse +import matplotlib.pyplot as plot +import gudhi """ This file is part of the Gudhi Library - https://gudhi.inria.fr/ - which is released under MIT. See file LICENSE or go to https://gudhi.inria.fr/licensing/ for full license details. @@ -47,7 +48,7 @@ with open(args.file, "r") as f: message = "RipsComplex with max_edge_length=" + repr(args.max_edge_length) print(message) - point_cloud = gudhi.read_off(off_file=args.file) + point_cloud = gudhi.read_points_from_off_file(off_file=args.file) rips_complex = gudhi.RipsComplex( points=point_cloud, max_edge_length=args.max_edge_length ) @@ -64,8 +65,8 @@ with open(args.file, "r") as f: print(simplex_tree.betti_numbers()) if args.no_diagram == False: - pplot = gudhi.plot_persistence_diagram(diag, band=args.band) - pplot.show() + gudhi.plot_persistence_diagram(diag, band=args.band) + plot.show() else: print(args.file, "is not a valid OFF file") diff --git a/src/python/example/rips_persistence_diagram.py b/src/python/example/rips_persistence_diagram.py index f5897d7b..2a90b4bc 100755 --- a/src/python/example/rips_persistence_diagram.py +++ b/src/python/example/rips_persistence_diagram.py @@ -1,5 +1,6 @@ #!/usr/bin/env python +import matplotlib.pyplot as plot import gudhi """ This file is part of the Gudhi Library - https://gudhi.inria.fr/ - which is released under MIT. @@ -26,5 +27,5 @@ simplex_tree = rips.create_simplex_tree(max_dimension=1) diag = simplex_tree.persistence(homology_coeff_field=2, min_persistence=0) print("diag=", diag) -pplot = gudhi.plot_persistence_diagram(diag) -pplot.show() +gudhi.plot_persistence_diagram(diag) +plot.show() diff --git a/src/python/example/sparse_rips_persistence_diagram.py b/src/python/example/sparse_rips_persistence_diagram.py index 671d5e34..410a6a86 100755 --- a/src/python/example/sparse_rips_persistence_diagram.py +++ b/src/python/example/sparse_rips_persistence_diagram.py @@ -1,5 +1,6 @@ #!/usr/bin/env python +import matplotlib.pyplot as plot import gudhi """ This file is part of the Gudhi Library - https://gudhi.inria.fr/ - which is released under MIT. @@ -28,5 +29,5 @@ simplex_tree = rips.create_simplex_tree(max_dimension=2) diag = simplex_tree.persistence(homology_coeff_field=2, min_persistence=0) print("diag=", diag) -pplot = gudhi.plot_persistence_diagram(diag) -pplot.show() +gudhi.plot_persistence_diagram(diag) +plot.show() diff --git a/src/python/example/tangential_complex_plain_homology_from_off_file_example.py b/src/python/example/tangential_complex_plain_homology_from_off_file_example.py index 456bc9eb..f0df2189 100755 --- a/src/python/example/tangential_complex_plain_homology_from_off_file_example.py +++ b/src/python/example/tangential_complex_plain_homology_from_off_file_example.py @@ -1,7 +1,8 @@ #!/usr/bin/env python -import gudhi import argparse +import matplotlib.pyplot as plot +import gudhi """ This file is part of the Gudhi Library - https://gudhi.inria.fr/ - which is released under MIT. See file LICENSE or go to https://gudhi.inria.fr/licensing/ for full license details. @@ -56,8 +57,8 @@ with open(args.file, "r") as f: print(st.betti_numbers()) if args.no_diagram == False: - pplot = gudhi.plot_persistence_diagram(diag, band=args.band) - pplot.show() + gudhi.plot_persistence_diagram(diag, band=args.band) + plot.show() else: print(args.file, "is not a valid OFF file") |