why i always getting input undefined

i had code my code like this

a1 = input(1);
b0 = input(2);
a2 = input(3);
b1 = input(4);
d = input(5);       

% check inputs
if (d<1)
   disp('ba2.m: Input parameter d (dead time) must be greater or equal 1');
   disp('       parameter value has been changed to 1');
   d = 1;
else
   d = round(d);
end;

if (b0==0)
   b0 = b1;
   b1 = 0;
   d = d+1;
end;
d = max([round(d)],1);

%compute the controller parameters
gama = b1/b0;
if ((gama <= 0) | (gama == 1))
   ki = 1/(2*d-1);
   %use serial filter 1/(1 + gama*z^-1)
   p1 = -1+gama;
   p2 = -gama;
else  %gama>0
   ki = 1/(2*d*(1+gama)*(1-gama));
   p1 = -1;
  p2 = 0;
end;
q0=ki/b0;
q1=q0*a1;
q2=q0*a2;

qp=[q0; q1; q2; p1; p2];

and always getting error

??? Input argument "input" is undefined.

Error in ==> ba2 at 31
a1 = input;

please can anyone give me idea about this thx

Answer 1

[David Barry]

It's because you are not using the input function correctly. Either that or you didn't realise input is a MATLAB function, in which case you should rename your variable.

a1 = input('Please enter your input for a1:');

https://uk.mathworks.com/help/matlab/ref/input.html

[reza kemal]

thx that was helped me :)

[David Barry]

Great. Please accept the answer then.