function GlobalVars

% Create a local variable w, assign a value to it, and then
% see if the function Globalw can "see" it
w = 23.5;
Globalw
pause

% Now use the global command for a local variables x and y, assign
% values to them, and then see if the function Globalxy can "see" them
global x y
x = 57.4;
y = 89.1;
Globalxy
pause

% Finally create a local variable z that we want to keep around between
% calls to function GlobalVars, and see how z changes from one call of
% GlobalVars to the next, and also if the function Globalz can "see" it.

persistent z count first_time

if isempty(first_time)
    z = 48.3;
    count = 1;
    first_time = false;
else
    z = z+2;
    count = count+1;
end

fprintf('The current value of z is %4.1f\n', z)
if count == 1
    fprintf('and the program has been called 1 time.\n')
else
    fprintf('and the program has been called %d times.\n', count)
end
pause

Globalz

%-------------------------------------------------------------------------
function Globalw

% First see if the variable x defined in GlobalVars can be
% accessed by this function
if exist('w')
    fprintf('The value of w is %4.1f in function Globalw.\n', w)
else
    fprintf('No value has been assigned to w in function Globalw.\n')
end

%-------------------------------------------------------------------------
function Globalxy

% Next see if the variables x and y defined in GlobalVars can be
% accessed by this function
global x y

if exist('x') & exist('y')
    fprintf('The value of x is %4.1f in function Globalxy\n', x)
    fprintf('The value of y is %4.1f in function Globalxy\n', y)
else
    fprintf('No value has been assigned to x or y in function Globalxy.\n')
end

%-------------------------------------------------------------------------
function Globalz

% First see if the persistent variable z defined in GlobalVars can be
% accessed by this function
if exist('z')
    fprintf('The value of z is %4.1f in function Globalz.\n', z)
else
    fprintf('No value has been assigned to z in function Globalz.\n')
end