solve command

[x,y] = meshgrid(-3:1:3);
z = 1.5*x - 3;
mesh(x,y,z);
p = -1.5*pi;
q = -pi/2;
r = 0;
for i = 1:1:10
  pause(0.1);
  p = p + (0.0173*5);
  q = q + (0.0173*5);
  r = r + (0.0173*5);
  a1 = 3*cos(p); b1 = 3*sin(p); c1 = -3;
  a2 = 3*cos(q); b1 = 3*sin(q); c2 = -3;
  a3 = 2*cos(r); b3 = 2*sin(r); c3 = 0;
  syms a b c d 
  eq1 = 'a1*a + b1*b +c1*c -d =0';
  eq2 = 'a2*a + b2*b + c2*c -d=0';
  eq3 = 'a3*a + b3*b +c3*c -d =0';
  [a,b,c] = solve(eq1,eq2,eq3,'a,b,c');
  a = a/d;b = b/d; c = c/d;
  disp(a);disp(b);disp(c);
  z = -(a*x + b*y)/c;
  mesh(x,y,z);
end

sir with the above code i am not able to get the interger value of a,b,c;the solution for this is

-(-b1*c2+b1*c3+b2*c1-b3*c1+b3*c2-b2*c3)/(-a1*b3*c2+a1*b2*c3+a3*b1*c2-b2*a3*c1+b3*a2*c1-a2*b1*c3)

(-a1*c2+a1*c3-a3*c1-a2*c3+a2*c1+a3*c2)/(-a1*b3*c2+a1*b2*c3+a3*b1*c2-b2*a3*c1+b3*a2*c1-a2*b1*c3)  

(-b2*a3+a1*b2-a1*b3+b3*a2+a3*b1-a2*b1)/(-a1*b3*c2+a1*b2*c3+a3*b1*c2-b2*a3*c1+b3*a2*c1-a2*b1*c3)

so can anyone tell me how to access a1,b1,c1 in solve function.can use any other method for this thank you

Answer 1

[Alexander]

Seems to be the same problem as here: http://www.mathworks.de/matlabcentral/answers/40281-substitution-after-differentiation-easy

Try this:

a = double(subs(a)); b = double(subs(b)); c = double(subs(c));

Like here:

[x,y] = meshgrid(-3:1:3);
z = 1.5*x - 3;
mesh(x,y,z);
p = -1.5*pi;
q = -pi/2;
r = 0;
for i = 1:1:10
  pause(0.1);
  p = p + (0.0173*5);
  q = q + (0.0173*5);
  r = r + (0.0173*5);
  a1 = 3*cos(p); b1 = 3*sin(p); c1 = -3;
  a2 = 3*cos(q); b2 = 3*sin(q); c2 = -3;
  a3 = 2*cos(r); b3 = 2*sin(r); c3 = 0;
  syms a b c d 
  eq1 = 'a1*a + b1*b +c1*c -d =0';
  eq2 = 'a2*a + b2*b + c2*c -d=0';
  eq3 = 'a3*a + b3*b +c3*c -d =0';
  [a,b,c] = solve(eq1,eq2,eq3,'a,b,c');
  a = a/d;b = b/d; c = c/d;
  a = double(subs(a)); b = double(subs(b)); c = double(subs(c));
  disp(a);disp(b);disp(c);
  z = -(a*x + b*y)/c;
  mesh(x,y,z);
end

Please note that I renamed one of your b1 to b2.

Answer 2

[Andrei Bobrov]

[x,y] = meshgrid(-3:1:3); 
pqr = reshape(bsxfun(@plus,[-1.5;-.5;0]*pi,(1:10)*0.0173*5),3,1,[]); 
abc = cat(2,cos(pqr),sin(pqr),bsxfun(@times,[-1;-1;0]*3,ones(1,1,10))); 
o3 = ones(3,1); 
for jj = 1:size(abc,3) 
    b = abc(:,:,jj)\o3; 
    mesh(x,y,-(b(1)*x + b(2)*y)/b(3));
    pause(0.5); 
end