Update to meshgen

Update meshgen to improve documentation, improve benchmarking and add in a unit test

benchmark/MeshGen/square.morpho

@@ -0,0 +1,10 @@
+// Square domain with a hole 
+import meshgen
+import plot
+
+var e0 = Domain(fn (x) ((x[0])^2+x[1]^2-1))
+var mg = MeshGen(e0, [-2..2:0.2, -2..2:0.2], quiet=true)
+var m = mg.build()
+
+print m
+

benchmark/benchmark.py

@@ -8,6 +8,7 @@
 from colored import stylize
 import subprocess
 
+"""
 languages = { "morpho": "morpho5",
               "m3": "morpho3",
               "fe": "evolver",
@@ -18,6 +19,9 @@
               "rb": "ruby",
               "dart": "dart"
             }
+"""
+
+languages = { "morpho": "morpho5" }
 
 # Gets the output generated
 def getoutput(filepath):

examples/meshgen/ellipse.morpho

@@ -3,6 +3,6 @@ import meshgen
 import plot
 
 var e0 = Domain(fn (x) -((x[0]/2)^2+x[1]^2-1))
-var mg = MeshGen(e0, [-2..2:0.2, -1..1:0.2], quiet=false)
+var mg = MeshGen(e0, [-2..2:0.2, -1..1:0.2])
 var m = mg.build()
 Show(plotmesh(m, grade=1))

examples/tactoid/tactoid.morpho

@@ -23,7 +23,7 @@ bnd.addgrade(0)
 var sigma=5.0*0.04 // Surface tension
 var W=3.0  // Anchoring
 
-var itermax = 8
+var itermax = 4
 
 // Set up the optimization problem
 var problem = OptimizationProblem(m)

morpho5/docs/meshgen.md

@@ -44,19 +44,25 @@ There are also a number of properties of a `MeshGen` object that can be set prio
 
 [showsubtopics]: # (subtopics)
 
-## Domain 
+## Domain
 [tagdomain]: # (domain)
 
-The `Domain` class is used to conveniently build a
+The `Domain` class is used to conveniently build a domain by composing simpler elements. 
 
-var a = CircularDomain([-0.5,0], 1)
-var b = CircularDomain([0.5,0], 1)
+Create a `Domain` from a scalar function that is positive in the region of interest:
 
-var dom = a.union(b).difference(c)
+    var dom = Domain(fn (x) -(x[0]^2+x[1]^2-1))
+
+You can pass it to `MeshGen` to specify the region to mesh: 
+
+    var mg = MeshGen(dom, [-1..1:0.2, -1..1:0.2])
 
 You can combine `Domain` objects using set operations `union`, `intersection` and `difference`: 
 
-    var a = (s1.intersection(s2)).union(s3)
+    var a = CircularDomain(Matrix([-0.5,0]), 1)
+    var b = CircularDomain(Matrix([0.5,0]), 1)
+    var c = CircularDomain(Matrix([0,0]), 0.3)
+    var dom = a.union(b).difference(c)
 
 ## CircularDomain
 [tagcirculardomain]: # (circulardomain)

test/modules/meshgen/disk.morpho

@@ -0,0 +1,10 @@
+// Domain composed of a single disk
+import meshgen
+import plot
+
+var dom = fn (x) -(x[0]^2+x[1]^2-1)
+var mg = MeshGen(dom, [-1..1:0.2, -1..1:0.2], quiet=true)
+var m = mg.build()
+
+print ismesh(m)
+// expect: true