--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/+grid/evalOnScalar.m	Tue Sep 06 15:51:41 2016 +0200
@@ -0,0 +1,39 @@
+% Takes a funciton and evaluates it on a grid to return a grid function in the
+% form of a (n*k)x1 vector, where n is the number of grid points and k is the
+% number of components of the function.
+%      g -- Grid to evaluate on.
+%   func -- Function to evaluate. May be a function handle or a constant. If
+%           it is a vector value it has to be provided as a column vector,
+function gf = evalOn(g, func)
+    if ~isa(func, 'function_handle')
+        % We should have a constant.
+        if size(func,2) ~= 1
+            error('grid:evalOn:VectorValuedWrongDim', 'A vector valued function must be given as a column vector')
+        end
+
+        gf = repmat(func,[g.N, 1]);
+        return
+    end
+    % func should now be a function_handle
+
+    % Get coordinates and convert to cell array for easier use as a parameter
+    x = g.points();
+    X = {};
+    for i = 1:size(x, 2)
+        X{i} = x(:,i);
+    end
+
+    % Find the number of components
+    x0 = num2cell(x(1,:));
+    f0 = func(x0{:});
+    k = length(f0);
+
+    if size(f0,2) ~= 1
+        error('grid:evalOn:VectorValuedWrongDim', 'A vector valued function must be given as a column vector')
+    end
+
+    gf = func(X{:});
+    if  k > 1  % Reorder so that componets sits together.
+        gf = reshape(reshape(gf, [g.N, k])', [g.N*k, 1]);
+    end
+end
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/+grid/evalOnScalarTest.m	Tue Sep 06 15:51:41 2016 +0200
@@ -0,0 +1,118 @@
+function tests = evalOnScalarTest()
+    tests = functiontests(localfunctions);
+end
+
+function testInputConstant(testCase)
+    in  = {
+        0,
+        47,
+        1,
+        [1; 2],
+    };
+
+    out = {
+        [0; 0; 0],
+        [47; 47; 47],
+        [1; 1; 1],
+        [1; 2; 1; 2; 1; 2],
+    };
+
+    g = getTestGrid('1d');
+
+    for i = 1:length(in)
+        gf = grid.evalOnScalar(g,in{i});
+        testCase.verifyEqual(gf, out{i});
+    end
+end
+
+function testInputScalarFunction1d(testCase)
+    in  = {
+        @(x)1+x*0,
+        @(x)x,
+        @(x)x.*x,
+    };
+
+    out = {
+        [1; 1; 1],
+        [0; 1; 2],
+        [0; 1; 4],
+    };
+
+    g = getTestGrid('1d');
+
+    for i = 1:length(in)
+        gf = grid.evalOnScalar(g,in{i});
+        testCase.verifyEqual(gf, out{i});
+    end
+end
+
+function testInputScalarFunction2d(testCase)
+    in  = {
+        @(x,y)1+x*0,
+        @(x,y)x-y,
+        @(x,y)x./(1+y),
+    };
+
+    out = {
+        [1; 1; 1; 1; 1; 1; 1; 1; 1],
+        [0; -1; -2; 1; 0; -1; 2; 1; 0],
+        [0; 0; 0; 1; 1/2; 1/3; 2; 1; 2/3],
+    };
+
+    g = getTestGrid('2d');
+
+    for i = 1:length(in)
+        gf = grid.evalOnScalar(g, in{i});
+        testCase.verifyEqual(gf, out{i});
+    end
+end
+
+
+function testInputVectorFunction(testCase)
+    g = getTestGrid('1d');
+    in = @(x)[x; -2*x];
+    out = [0; 0; 1; -2; 2; -4];
+
+    gf = grid.evalOnScalar(g,in);
+    testCase.verifyEqual(gf, out);
+
+    g = getTestGrid('2d');
+    in = @(x,y)[x.^2; -2*y];
+    out = [
+        0;  0;
+        0; -2;
+        0; -4;
+        1;  0;
+        1; -2;
+        1; -4;
+        4;  0;
+        4; -2;
+        4; -4;
+    ];
+
+    gf = grid.evalOnScalar(g,in);
+    testCase.verifyEqual(gf, out);
+end
+
+
+function testInputErrorVectorValued(testCase)
+     in  = {
+        [1,2,3],
+        @(x,y)[x,-y];
+    };
+
+    g = getTestGrid('2d');
+
+    for i = 1:length(in)
+        testCase.verifyError(@()grid.evalOnScalar(g, in{i}),'grid:evalOnScalar:VectorValuedWrongDim',sprintf('in(%d) = %s',i,toString(in{i})));
+    end
+end
+
+function g = getTestGrid(d)
+    switch d
+        case '1d'
+            g = grid.equidistant(3,{0,2});
+        case '2d'
+            g = grid.equidistant([3,3],{0,2},{0,2});
+    end
+end