//
// state.sce
//
// A first order integration of an accelerating mass
//
// To run this in Scilab use 'File' then 'Exec'.
//
// by: J. Slater J Briceno
//


// System component values

x1 = 8;		// initial conditions
v1 = 12;
x2 = 9;
v2 = 4;
ks1=1;
ks2=2;
ks3=2;
kd1=1;
kd2=2;
kd3=1;
m1=100;
m2=50;
force=100;

X=[x1, v1, x2, v2];

// define the state matrix function
// the values returned are [x, v]
function foo=f(state,t)
	foo = [ state($, 2), (-ks1-ks2)/m1* state($, 1)+(-kd1-kd2)/m1*state($,2)+ks2/m1*state($,3)+kd2/m1*state($,4), state($, 4), ks2/m2*state($,1)+kd2/m2*state($,2)+(-ks2-ks3)/m2*state($,3)+(-kd2-kd3)/m2*state($,4)-force/m2];
endfunction


// Set the time length and step size for the integration
steps = 100;
t_start = 0;
t_end = 1;
h = (t_end - t_start) / steps;


//
// Loop for integration
//
for i=1:steps,
	X = [X ; X($,:) + h*f(X, i*h)];
end
printf("The value at the end of first order integration is (x, v) = (%f, %f)\n", ...
	X($,1),	...
	X($,2), ...
	X($,3), ...
	X($,4));