i%给圆心(a,b)返回安全系数K
function output=damnk(a,b)
syms cita h r c gama fi n i Tn Rn jiajiao l z n1
cita=50;
h=50;
c=20;
gama=18;
fi=35;
n=10;
r=(a^2+b^2)^(1/2);
n1=(a+(r^2-(h-b)^2)^(1/2))/n;
i=1;
Tn=0;
Rn=0;
while(i<=n)
Ri=int('(x*tand(cita)+0-b+(r^2-(x-a)^2)^(1/2))*(r^2-(x-a)^2)^(1/2)/r','x',(i-1)*n1,i*n1);
Ti=int('x*tand(cita)+0-b+(r^2-(x-a)^2)^(1/2)','x',(i-1)*n1,i*n1);
Rn=Rn+Ri;
Tn=Tn+Ti;
i=i+1;
end
jiajiao=acosd(dot([0-a,0-b],[(a+(r^2-(h-b)^2)^(1/2))-a,h-b])/(norm([0-a,0-b])*norm([0-a,h-b])));
l=2*pi*r*(jiajiao/360);
z=(Rn*tand(fi)+c*l/gama)/Tn;
output=z;