Feature: RegionShapes

doc/templates/api-template.html

@@ -42,7 +42,7 @@ <h3>Basics</h3>
     <li class="pure-menu-item"><a href="#" class="pure-menu-link api-section-link" onclick="openSection(event, 'mesh')">Mesh size and geometry</a></li>
     <li class="pure-menu-item"><a href="#" class="pure-menu-link api-section-link" onclick="openSection(event, 'shapes')">Shapes</a></li>
     <li class="pure-menu-item"><a href="#" class="pure-menu-link api-section-link" onclick="openSection(event, 'regions')">Material regions</a></li>
-    <li class="pure-menu-item"><a href="#" class="pure-menu-link api-section-link" onclick="openSection(event, 'initial')">Initial Magnetization</a></li>
+    <li class="pure-menu-item"><a href="#" class="pure-menu-link api-section-link" onclick="openSection(event, 'initial')">Initial magnetization</a></li>
     <li class="pure-menu-item"><a href="#" class="pure-menu-link api-section-link" onclick="openSection(event, 'parameters')">Material parameters</a></li>
     <li class="pure-menu-item"><a href="#" class="pure-menu-link api-section-link" onclick="openSection(event, 'excitation')">Excitation</a></li>
     <li class="pure-menu-item"><a href="#" class="pure-menu-link api-section-link" onclick="openSection(event, 'outputquantities')">Output quantities</a></li>

doc/templates/examples-template.html

@@ -222,7 +222,7 @@ <h2 id="ex_SP4">Getting started with Standard Problem #4</h2>
 
 Note: these are 3D geometries seen from above. The displayed cell filling is averaged along the thickness (notable in ellipse and layers example). Black means empty space, white is filled.
 
-<hr/><h2 id="ex_initmag">Initial Magnetization</h2>
+<hr/><h2 id="ex_initmag">Initial magnetization</h2>
 Some initial magnetization functions are provided, as well as transformations similar to those on Shapes. See the Config <a href="http://mumax.github.io/api.html">API</a>.
 
 {{.Example `
@@ -280,7 +280,7 @@ <h2 id="ex_SP4">Getting started with Standard Problem #4</h2>
 The magnetization can also be set in separate regions, see below.
 
 
-<hr/><h2 id="ex_cheese">Interlude: Rotating Cheese</h2>
+<hr/><h2 id="ex_cheese">Interlude: rotating cheese</h2>
 
 In this example we define a geometry that looks like a slice of cheese and have it rotate in time.
 
@@ -317,7 +317,7 @@ <h2 id="ex_SP4">Getting started with Standard Problem #4</h2>
 {{.Output}}
 
 
-<hr/><h2 id="ex_regions">Regions: Space-dependent Parameters</h2>
+<hr/><h2 id="ex_regions">Regions: space-dependent parameters</h2>
 
 <p>Space-dependent parameters are defined using material <i>regions</i>. Regions are numbered 0-255 and represent different materials. Each cell can belong to only one region. At the start of a simulation all cells have region number 0.</p>
 
@@ -429,7 +429,7 @@ <h2 id="ex_SP4">Getting started with Standard Problem #4</h2>
 {{.Output}}
 
 
-<hr/><h2 id="ex_PMA">PMA Racetrack</h2>
+<hr/><h2 id="ex_PMA">PMA racetrack</h2>
 In this example we drive a domain wall in PMA material by spin-transfer torque.  We set up a post-step function that makes the simulation box "follow" the domain wall. Like this, only a small number of cells is needed to simulate an infinitely long magnetic wire.
 
 {{.Example `
@@ -463,7 +463,7 @@ <h2 id="ex_SP4">Getting started with Standard Problem #4</h2>
 Since we center on the domain wall we can not see that it is actually moving, but the domain wall breakdown is visible.
 
 
-<hr/><h2 id="ex_Py">Py Racetrack</h2>
+<hr/><h2 id="ex_Py">Py racetrack</h2>
 
 In this example we drive a vortex wall in Permalloy by spin-transfer torque. The simulation box "follows" the domain wall. By removing surface charges at the left and right ends, we mimic an infintely long wire.
 

engine/ext_regionshapes.go

@@ -0,0 +1,34 @@
+package engine
+
+import (
+	"github.com/mumax/3/data"
+)
+
+func init() {
+	DeclFunc("ext_AllRegionShapes", ext_AllRegionShapes, "Returns a function that gives the shape of each region. Does not automatically update if the region is redefined or moved with Shift. Call as: allregions := ext_AllRegionShapes(); shape := allregions(i); on seperate lines. Note: double parentheses as ext_AllRegionShapes()(i) are not supported in mx3 scripts and must be split across two lines.")
+}
+
+func ext_AllRegionShapes() func(int) Shape {
+	mesh := Mesh()
+	arr := regions.HostList()
+	n := mesh.Size()
+	d := mesh.CellSize()
+	Lx, Ly, Lz := float64(n[X])*d[X], float64(n[Y])*d[Y], float64(n[Z])*d[Z]
+
+	return func(region int) Shape {
+		defRegionId(region)
+
+		return func(x, y, z float64) bool {
+			ix := int((x + 0.5*Lx) / d[X])
+			iy := int((y + 0.5*Ly) / d[Y])
+			iz := int((z + 0.5*Lz) / d[Z])
+
+			if ix < 0 || ix >= n[X] || iy < 0 || iy >= n[Y] || iz < 0 || iz >= n[Z] {
+				return false
+			}
+
+			i := data.Index(n, ix, iy, iz)
+			return arr[i] == byte(region)
+		}
+	}
+}

test/ext_AllRegionShapes.mx3

@@ -0,0 +1,53 @@
+/*
+	Test the ext_AllRegionShapes extension, by comparing Shapes to Regions
+*/
+
+//This example uses Voronoi Tesselation regions, but ext_AllRegionShapes works with any other types of regions
+//Set arbitrary initial conditions
+N := 256
+c := 4e-9
+d := 40e-9
+setgridsize(N, N, 1)
+setcellsize(c, c, d)
+setGeom(circle(N*c))
+alpha = 3
+Kc1   = 1000
+Aex   = 13e-12
+Msat  = 860e3
+m=randommag()
+
+// define grains with region number 0-255
+grainSize  := 40e-9  // m
+randomSeed := 1234567
+maxRegion  := 254
+ext_makegrains(grainSize, maxRegion, randomSeed)
+
+//Zero out only half the regions, and save the average remaining magnetization
+for i:=0; i<maxRegion/2; i++{
+m.setregion(i,uniform(0,0,0))
+}
+
+mregionsavg:=m.average()
+
+//Reset so we can compare to Shapes equivalent
+m=randommag()
+
+// If we would like to add up several grains, we can initialize a shape with nothing in it, and then add to it in a loop.
+a:=circle(0e-9)
+
+//Initialize ext_Allregionshapes. By itself, ext_AllRegionShapes() is not yet a Shape, but still a func()
+//We can access the ith region using allregions(i). mx3 scripts do not allow double parentheses ext_AllRegionShapes()(i) on one line
+allregions:= ext_AllRegionShapes()
+
+//We can also add these Shapes in a loop. Here, add each Shape corresponding with the previous maxRegion/2 grains to compare
+for i:=0; i<maxRegion/2; i++{
+a=a.add(allregions(i))
+}
+//zero them out, as before
+m.setinshape(a,uniform(0,0,0))
+
+mshapesavg:=m.average()
+
+
+expectv("Average Magnetization",mregionsavg,mregionsavg,1e-8)
+