update 2 demos

Author: amal-ghamdi

demos/demo01_1D_Diffusion.ipynb

@@ -142,7 +142,7 @@
     "                                                SNR=SNR,\\\n",
     "                                                mapping=mapping,\\\n",
     "                                                left_bc=1,\\\n",
-    "                                                right_bc=8,\\\n",
+    "                                                right_bc=50,\\\n",
     "                                                endpoint=L).get_components()\n"
    ]
   },
@@ -277,8 +277,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "prior = cuqi.distribution.GMRF(np.zeros(model.domain_dim),25,1,'zero',\\\n",
-    "                               geometry=model.domain_geometry)\n"
+    "prior = cuqi.distribution.GMRF(0.015+np.zeros(model.domain_dim), 300, 'zero', 1)\n"
    ]
   },
   {
@@ -316,8 +315,10 @@
    "source": [
     "Ns = 5000\n",
     "np.random.seed(0)\n",
-    "sampler = cuqi.sampler.pCN(posterior)\n",
-    "samples = sampler.sample_adapt(Ns)\n"
+    "sampler = cuqi.sampler.PCN(posterior, initial_point=np.zeros(prior.dim), scale=0.15)\n",
+    "sampler.warmup(1000)\n",
+    "sampler.sample(5000)\n",
+    "samples = sampler.get_samples().burnthin(1000)\n"
    ]
   },
   {
@@ -389,7 +390,7 @@
  ],
  "metadata": {
   "kernelspec": {
-   "display_name": "Python 3.10.5 ('fenicsproject')",
+   "display_name": "fenicsproject",
    "language": "python",
    "name": "python3"
   },
@@ -404,11 +405,6 @@
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
    "version": "3.10.5"
-  },
-  "vscode": {
-   "interpreter": {
-    "hash": "f83c72a7c5d885a4a7f43561cb77434137f6f5cf21a7418d4732e18616218db3"
-   }
   }
  },
  "nbformat": 4,

demos/demo01_1D_Diffusion.py

@@ -22,7 +22,7 @@
 SNR = 1000
 model, data, problemInfo = cuqipy_fenics.testproblem.FEniCSDiffusion1D(dim=dim,
     exactSolution=myExactSolution, observation_operator=observation_operator,
-    SNR=SNR, mapping=mapping, left_bc=1, right_bc=20, endpoint=L
+    SNR=SNR, mapping=mapping, left_bc=1, right_bc=50, endpoint=L
     ).get_components()
 
 #%% Plot data