added functions to add and remove nodes from model

src/JuliaFEM.jl

@@ -71,5 +71,50 @@ function get_field(field_type, field_name; create_if_doesnt_exist=false)
 end
 
 
+function add_nodes(model, nodes)
+    """Add new nodes to model.
+
+    Parameters
+    ----------
+    nodes : Dict()
+        id => coords
+
+    Returns
+    -------
+    model
+
+    Notes
+    -----
+    Create new field "coords" to model if not found
+    """
+
+    println("Adding ", length(nodes), " nodes to model")
+    field = get_field(model.nodes, "coords"; create_if_doesnt_exist=true)
+    for (node_id, coords) in nodes
+        field[node_id] = coords
+    end
+end
+
+
+function get_nodes(model, node_ids)
+    """Return subset of nodes from model.
+
+    Parameters
+    ----------
+    node_ids : array
+        list of node ids to return
+
+    Returns
+    -------
+    Dict()
+        id => coords
+    """
+    subset = Dict()
+    for node_id in node_ids
+        subset[node_id] = model.nodes["coords"][node_id]
+    end
+    return subset
+end
+
 
 end # module

test/runtests.jl

@@ -1,6 +1,7 @@
 using JuliaFEM
 using Base.Test
 
+
 function test_create_model()
     m = new_model()
     fn = fieldnames(m)
@@ -11,12 +12,14 @@ function test_create_model()
     @assert :element_gauss_points in fn
 end
 
+
 function test_add_field()
     m = new_model()
     field = new_field(m.elements, "color")
     @assert "color" in keys(m.elements)
 end
 
+
 function test_get_field()
     m = new_model()
     field = new_field(m.elements, "color")
@@ -25,6 +28,7 @@ function test_get_field()
     @assert field2[1] == "red"
 end
 
+
 function test_get_field_if_it_doesnt_exist()
     m = new_model()
     # FIXME: how to test exception?
@@ -36,6 +40,19 @@ function test_get_field_if_it_doesnt_exist()
 end
 
 
+function test_add_and_get_nodes()
+    m = new_model()
+    nodes = Dict(1 => [0.0, 0.0, 0.0],
+                 2 => [1.0, 0.0, 0.0],
+                 3 => [0.0, 1.0, 0.0],
+                 4 => [0.0, 0.0, 1.0])
+    add_nodes(m, nodes)
+    subset = get_nodes(m, [2, 3])
+    @assert length(subset) == 2
+    @assert subset[2] == [1.0, 0.0, 0.0]
+    @assert subset[3] == [0.0, 1.0, 0.0]
+end
+
 # write your own tests here
 # @test 1 == JuliaFEM.test()
 # @test_approx_eq 1.0 1.0