diff --git a/examples/jupyter/demo1_diffusion.ipynb b/examples/jupyter/demo1_diffusion.ipynb
index d4f91a758..2664d207b 100644
--- a/examples/jupyter/demo1_diffusion.ipynb
+++ b/examples/jupyter/demo1_diffusion.ipynb
@@ -90,8 +90,6 @@
     "# -- 2D --\n",
     "elseif dimension == 2\n",
     "    # compute\n",
-    "    θ_plotting_x = zeros(numberruns)\n",
-    "    θ_plotting_y = zeros(numberruns)\n",
     "    maxeigenvalues = zeros(numberruns, numberruns)\n",
     "\n",
     "    for i in 1:numberruns, j in 1:numberruns\n",
@@ -107,14 +105,21 @@
     "\n",
     "    # plot\n",
     "    println(\"max eigenvalue: \", maxeigenvalue)\n",
+    "    xrange = θ_min/π:(θ_max - θ_min)/π/(numberruns-1):θ_max/π\n",
     "    heatmap(\n",
+    "        xrange,\n",
+    "        xlabel=\"θ/π\",\n",
+    "        xtickfont=font(12, \"Courier\"),\n",
+    "        xrange,\n",
+    "        ylabel=\"θ/π\",\n",
     "        maxeigenvalues,\n",
+    "        ytickfont=font(12, \"Courier\"),\n",
     "        title=\"Diffusion Operator Symbol\",\n",
     "        transpose=true,\n",
     "        aspect_ratio=:equal\n",
     "    )\n",
-    "    xlims!(1, numberruns)\n",
-    "    ylims!(1, numberruns)\n",
+    "    xlims!(θ_min/π, θ_max/π)\n",
+    "    ylims!(θ_min/π, θ_max/π)\n",
     "end"
    ]
   }
diff --git a/examples/jupyter/demo2_jacobi.ipynb b/examples/jupyter/demo2_jacobi.ipynb
index 42bd42e72..f72608519 100644
--- a/examples/jupyter/demo2_jacobi.ipynb
+++ b/examples/jupyter/demo2_jacobi.ipynb
@@ -117,14 +117,21 @@
     "\n",
     "    # plot\n",
     "    println(\"max eigenvalue: \", maxeigenvalue)\n",
+    "    xrange = θ_min/π:(θ_max - θ_min)/π/(numberruns-1):θ_max/π\n",
     "    heatmap(\n",
+    "        xrange,\n",
+    "        xlabel=\"θ/π\",\n",
+    "        xtickfont=font(12, \"Courier\"),\n",
+    "        xrange,\n",
+    "        ylabel=\"θ/π\",\n",
+    "        ytickfont=font(12, \"Courier\"),\n",
     "        maxeigenvalues,\n",
     "        title=\"Jacobi Operator Symbol\",\n",
     "        transpose=true,\n",
     "        aspect_ratio=:equal\n",
     "    )\n",
-    "    xlims!(1, numberruns)\n",
-    "    ylims!(1, numberruns)\n",
+    "    xlims!(θ_min/π, θ_max/π)\n",
+    "    ylims!(θ_min/π, θ_max/π)\n",
     "end"
    ]
   }
diff --git a/examples/jupyter/demo3_pmultigrid.ipynb b/examples/jupyter/demo3_pmultigrid.ipynb
index d868ad0b1..352e1ff0b 100644
--- a/examples/jupyter/demo3_pmultigrid.ipynb
+++ b/examples/jupyter/demo3_pmultigrid.ipynb
@@ -4,7 +4,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "# P-multigrid Example"
+    "# Two-grid P-multigrid Example"
    ]
   },
   {
@@ -122,14 +122,21 @@
     "\n",
     "    # plot\n",
     "    println(\"max eigenvalue: \", maxeigenvalue)\n",
+    "    xrange = θ_min/π:(θ_max - θ_min)/π/(numberruns-1):θ_max/π\n",
     "    heatmap(\n",
+    "        xrange,\n",
+    "        xlabel=\"θ/π\",\n",
+    "        xtickfont=font(12, \"Courier\"),\n",
+    "        xrange,\n",
+    "        ylabel=\"θ/π\",\n",
+    "        ytickfont=font(12, \"Courier\"),\n",
     "        maxeigenvalues,\n",
     "        title=\"P-Multigrid Error Symbol\",\n",
     "        transpose=true,\n",
     "        aspect_ratio=:equal\n",
     "    )\n",
-    "    xlims!(1, numberruns)\n",
-    "    ylims!(1, numberruns)\n",
+    "    xlims!(θ_min/π, θ_max/π)\n",
+    "    ylims!(θ_min/π, θ_max/π)\n",
     "end"
    ]
   }
diff --git a/examples/jupyter/demo4_pmultigrid_multilevel.ipynb b/examples/jupyter/demo4_pmultigrid_multilevel.ipynb
index a382e1e12..24ff9c2e1 100644
--- a/examples/jupyter/demo4_pmultigrid_multilevel.ipynb
+++ b/examples/jupyter/demo4_pmultigrid_multilevel.ipynb
@@ -4,7 +4,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "# P-multigrid Example"
+    "# Three-grid P-multigrid Example"
    ]
   },
   {
@@ -127,14 +127,21 @@
     "\n",
     "    # plot\n",
     "    println(\"max eigenvalue: \", maxeigenvalue)\n",
+    "    xrange = θ_min/π:(θ_max - θ_min)/π/(numberruns-1):θ_max/π\n",
     "    heatmap(\n",
+    "        xrange,\n",
+    "        xlabel=\"θ/π\",\n",
+    "        xtickfont=font(12, \"Courier\"),\n",
+    "        xrange,\n",
+    "        ylabel=\"θ/π\",\n",
+    "        ytickfont=font(12, \"Courier\"),\n",
     "        maxeigenvalues,\n",
     "        title=\"P-Multigrid Error Symbol\",\n",
     "        transpose=true,\n",
     "        aspect_ratio=:equal\n",
     "    )\n",
-    "    xlims!(1, numberruns)\n",
-    "    ylims!(1, numberruns)\n",
+    "    xlims!(θ_min/π, θ_max/π)\n",
+    "    ylims!(θ_min/π, θ_max/π)\n",
     "end"
    ]
   }