global - Define global variable
Ordinarily, each Scilab function, has its own local variables and can "read" all variables created in the base workspace or by the calling functions. The global keyword allow to make variables read/write across functions. Any assignment to that variable, in any function, is available to all the other functions declaring it global.
If the global variable doesn't exist the first time you issue the global statement, it will be initialized to the empty matrix.
//first: calling environnment and a function share a variable
global a
a=1
deff('y=f1(x)','global a,a=x^2,y=a^2')
f1(2)
a
//second: three functions share variables
deff('initdata()','global A C ;A=10,C=30')
deff('letsgo()','global A C ;disp(A) ;C=70')
deff('letsgo1()','global C ;disp(C)')
initdata()
letsgo()
letsgo1()