diff --git a/pina/plotter.py b/pina/plotter.py
index 19823e5..4c2ef11 100644
--- a/pina/plotter.py
+++ b/pina/plotter.py
@@ -39,31 +39,33 @@ class Plotter:
             variables = problem.temporal_domain.variables
 
         if len(variables) not in [1, 2, 3]:
-            raise ValueError
+            raise ValueError('Samples can be plotted only in dimensions 1, 2 and 3.')
 
         fig = plt.figure()
         proj = '3d' if len(variables) == 3 else None
         ax = fig.add_subplot(projection=proj)
         for location in problem.input_pts:
             coords = problem.input_pts[location].extract(variables).T.detach()
-            if coords.shape[0] == 1:  # 1D samples
+            if len(variables)==1:  # 1D samples
                 ax.plot(coords.flatten(),
                         torch.zeros(coords.flatten().shape),
                         '.',
                         label=location,
                         **kwargs)
-            else:
+            elif len(variables)==2:
                 ax.plot(*coords, '.', label=location, **kwargs)
+            elif len(variables)==3:
+                ax.scatter(*coords, '.', label=location, **kwargs)
 
         ax.set_xlabel(variables[0])
         try:
             ax.set_ylabel(variables[1])
-        except:
+        except (IndexError, AttributeError):
             pass
 
         try:
             ax.set_zlabel(variables[2])
-        except:
+        except (IndexError, AttributeError):
             pass
 
         plt.legend()
diff --git a/tests/test_plotter.py b/tests/test_plotter.py
new file mode 100644
index 0000000..99f99bc
--- /dev/null
+++ b/tests/test_plotter.py
@@ -0,0 +1,69 @@
+from pina.geometry import CartesianDomain
+from pina import Condition, Plotter
+from matplotlib.testing.decorators import image_comparison
+import matplotlib.pyplot as plt
+from pina.problem import SpatialProblem
+from pina.equation import FixedValue
+
+        
+class FooProblem1D(SpatialProblem):
+
+    # assign output/ spatial and temporal variables
+    output_variables = ['u']
+    spatial_domain = CartesianDomain({'x' : [-1, 1]})
+
+    # problem condition statement
+    conditions = {
+        'D': Condition(location=CartesianDomain({'x': [-1, 1]}), equation=FixedValue(0.)),
+    }
+
+class FooProblem2D(SpatialProblem):
+
+    # assign output/ spatial and temporal variables
+    output_variables = ['u']
+    spatial_domain = CartesianDomain({'x' : [-1, 1], 'y': [-1, 1]})
+
+    # problem condition statement
+    conditions = {
+        'D': Condition(location=CartesianDomain({'x' : [-1, 1], 'y': [-1, 1]}), equation=FixedValue(0.)),
+    }
+
+class FooProblem3D(SpatialProblem):
+
+    # assign output/ spatial and temporal variables
+    output_variables = ['u']
+    spatial_domain = CartesianDomain({'x' : [-1, 1], 'y': [-1, 1], 'z':[-1,1]})
+
+    # problem condition statement
+    conditions = {
+        'D': Condition(location=CartesianDomain({'x' : [-1, 1], 'y': [-1, 1], 'z':[-1,1]}), equation=FixedValue(0.)),
+    }
+
+
+
+def test_constructor():
+    Plotter()
+
+def test_plot_samples_1d():
+    problem = FooProblem1D()
+    problem.discretise_domain(n=10, mode='grid', variables = 'x', locations=['D'])
+    pl = Plotter()
+    pl.plot_samples(problem=problem, filename='fig.png')
+    import os
+    os.remove('fig.png')
+
+def test_plot_samples_2d():
+    problem = FooProblem2D()
+    problem.discretise_domain(n=10, mode='grid', variables = ['x', 'y'], locations=['D'])
+    pl = Plotter()
+    pl.plot_samples(problem=problem, filename='fig.png')
+    import os
+    os.remove('fig.png')
+
+def test_plot_samples_3d():
+    problem = FooProblem3D()
+    problem.discretise_domain(n=10, mode='grid', variables = ['x', 'y', 'z'], locations=['D'])
+    pl = Plotter()
+    pl.plot_samples(problem=problem, filename='fig.png')
+    import os
+    os.remove('fig.png')
\ No newline at end of file