Undefined function 'atand' for input arguments of type 'sym'. how to solve this error?

I'm running the follow code lines

% tanB1 = X and tanB2 = Y
Cp = 1005
Ca = 200; % input
Um = 256;  % input

temp_rise = 34.5; % input
lambda = 0.84; % from stages (input)
DoR_factor = 0.5;% input

TpR = temp_rise*Cp/(lambda*Um*Ca);
DoR = DoR_factor*2*Um/Ca;

syms X Y
Eqn1 = 'TpR = X - Y';
Eqn2 = 'DoR = X + Y';

S = solve(Eqn1, Eqn2, X, Y);
soln = [S.X, S.Y];
m2 = subs(soln);

% deflection
B1 = atand(m2(1,1))
B2 = atand(m2(1,2))
% air angles from B1 and B2
A1 = atand(Um/Ca - tand(B1));
A2 = atand(Um/Ca - tand(B2));

deHall = (Ca/cosd(B2))/(Ca/cosd(B1));

% [B1, B2, A1, A2, 0, deHall];

A_angle = [B1, B2, A1, A2, 0, deHall]

But I am getting an error on the line B1,

??? Undefined function or method 'atan2' for input arguments of type 'sym'.

Any Ideas how to solve this problem?

Thanks!!

Answer 1

[Mischa Kim]

Tin, you need to convert the symbolic expressions. Use

 B1 = atand(double(m2(1,1)))
 B2 = atand(double(m2(1,2)))

[Tin Man To]

thanks a lot!it works:)

Answer 2

[Walter Roberson]

sym atand(x)
atand(x) = atan(x * 180/sym('PI'))

If necessary use a different function name.

atan is specifically documented to work on symbolic values.