[x1,y1,x2,y2,x3,y3,x4,y4,ax,ay,Vx,Vy,x_hc,y_hc,phi_hc]=square(x1,y1,x2,y2,x3,y3,x4,y4,i,phi_hFIX,check,ome,t,Tetha,np,incx,incy)

function [x1,y1,x2,y2,x3,y3,x4,y4,ax,ay,Vx,Vy,x_hc,y_hc,phi_hc]=square(x1,y1,x2,y2,x3,y3,x4,y4,i,phi_hFIX,check,ome,t,Tetha,np,incx,incy)
global  incx incy
if (i<=np/4)
    
    x_hc=x1;
    y_hc=y1;
    Vx=1;
    Vy=0;
    ax=.2;
    ay=0;
    x1=x1+incx;
elseif ((i>np/4)&(i<=np/2))
    
    x_hc=x2;
    y_hc=y1;
    Vx=0;
    Vy=1;
    ax=0;
    ay=0.2;
    y1=y1+incy;
elseif((i>np/2)&(i<=np*3/4))
    
    x_hc=x3;
    y_hc=y3;
    Vx=-1;
    Vy=0;
    ax=-.2;
    ay=0;
    x3=x3-incx;
elseif((i>np*3/4)&(i<=np+1))
    
    x_hc=x3;
    y_hc=y3;
    Vx=0;
    Vy=-1;
    ax=0;
    ay=-0.2;
    y3=y3-incy;
end

if (check==1)
    phi_hc=ome*t*57.29;
else
    phi_hc=phi_hFIX;
end