Bug fixes (typos).

tests/solver-test-functions/helicalvalley.m

@@ -49,7 +49,7 @@ if nargin==1
         fjac(3,2) = 0;
         fjac(3,3) = 1;
     end
-elseif nargin
+elseif ~nargin
     if nargout==1
         fval = [-1; 0; 0];
     else

tests/solver-test-functions/powell1.m

@@ -36,7 +36,7 @@ if nargin==1
         fjac(4,1) = 2*sqrt(10)*(x(1)-x(4));
         fjac(4,4) = -fjac(4,1);
     end
-elseif nargin
+elseif ~nargin
     if nargout==1
         fval = [3; -1; 0; 1];
     else

tests/solver-test-functions/powell2.m

@@ -28,7 +28,7 @@ if nargin==1
         fjac(2,1) = -exp(x(1));
         fjac(2,2) = -exp(x(2));
     end
-elseif nargin
+elseif ~nargin
     if nargout==1
         fval = [0; 1];
     else

tests/solver-test-functions/rosenbrock.m

@@ -28,7 +28,7 @@ if nargin==1
         fjac(2,1) = -20*x(1);
         fjac(2,2) = 10;
     end
-elseif nargin
+elseif ~nargin
     if nargout==1
         fval = [10000; 1];
     else

tests/solver-test-functions/wood.m

@@ -45,7 +45,7 @@ if nargin==1
         fjac(4,3) = -2*C6*x(3);
         fjac(4,4) = C6+C4;
     end
-elseif nargin
+elseif ~nargin
     if nargout==1
         fval = [-3; -1; -3; -1];
     else