How to form a function using 'for loop' without 'sym' command

i tried like this

m = 150;
Aos = 40;
nAi = 0;
for i=1:2:m
    nAi = @(phi)nAi+cos(i*phi);
end
nA = vpa((nAi+Aos), 4)

Iam getting this error

Operator '+' is not supported for operands of type 'function_handle'.

Error in ll (line 8)

nA = vpa(nAi+Aos, 4)

[Jan]

You did not mention, what you try to achieve. All we see is the failing code. This is not enough information to guess, what you want to get instead.

[Bathala Teja]

Its clearly there. i want to form nA interms of phi.

But i want to evalute without sym. Any idea.....

Answer 1

[Abolfazl Chaman Motlagh]

Assuming you want nA be function of phi, you can use symsum for summuation :

m = 150;
Aos = 40;
syms phi k
nAi =@(phi) symsum(cos(2*k*phi),k,1,m/2);
nA =@(phi)  vpa((nAi(phi)+Aos), 4);

% example
nA(pi)

ans = 

115.0

[Walter Roberson]

syms is an abbreviation for sym() so this does not satisfy the requirement to not use sym

[Abolfazl Chaman Motlagh]

Oh! sorry, i just read the content not title of question.

Answer 2

[Walter Roberson]

m = 150;
Aos = 40;
nAi = @(phi) zeros(size(phi));
for i=1:2:m
    nAi = @(phi)nAi(phi)+cos(i*phi);
end
nA = @(phi) nAi(phi)+Aos

nA = function_handle with value:
    @(phi)nAi(phi)+Aos

You asked to avoid sym, so it seems likely to me you want to avoid using vpa() as well. But if using a final vpa is okay, then

vpa(nA, 4)

ans = 

[Bathala Teja]

How to show result like this(ans which you shared) without vpa??

And you got result in the form of phi(means symbol), how to get symbol in place of phi??

[Walter Roberson]

With vpa(), the symbol for phi appears if you are using LiveScript, but not for traditional .m files.

To get the result without using vpa:

m = 150;
Aos = 40;
nA = str2func("@(phi) " + strjoin(compose("cos(%d*theta)", 1:2:m), " + ") + " + " + string(Aos))

nA = function_handle with value:
    @(phi)cos(1*theta)+cos(3*theta)+cos(5*theta)+cos(7*theta)+cos(9*theta)+cos(11*theta)+cos(13*theta)+cos(15*theta)+cos(17*theta)+cos(19*theta)+cos(21*theta)+cos(23*theta)+cos(25*theta)+cos(27*theta)+cos(29*theta)+cos(31*theta)+cos(33*theta)+cos(35*theta)+cos(37*theta)+cos(39*theta)+cos(41*theta)+cos(43*theta)+cos(45*theta)+cos(47*theta)+cos(49*theta)+cos(51*theta)+cos(53*theta)+cos(55*theta)+cos(57*theta)+cos(59*theta)+cos(61*theta)+cos(63*theta)+cos(65*theta)+cos(67*theta)+cos(69*theta)+cos(71*theta)+cos(73*theta)+cos(75*theta)+cos(77*theta)+cos(79*theta)+cos(81*theta)+cos(83*theta)+cos(85*theta)+cos(87*theta)+cos(89*theta)+cos(91*theta)+cos(93*theta)+cos(95*theta)+cos(97*theta)+cos(99*theta)+cos(101*theta)+cos(103*theta)+cos(105*theta)+cos(107*theta)+cos(109*theta)+cos(111*theta)+cos(113*theta)+cos(115*theta)+cos(117*theta)+cos(119*theta)+cos(121*theta)+cos(123*theta)+cos(125*theta)+cos(127*theta)+cos(129*theta)+cos(131*theta)+cos(133*theta)+cos(135*theta)+cos(137*theta)+cos(139*theta)+cos(141*theta)+cos(143*theta)+cos(145*theta)+cos(147*theta)+cos(149*theta)+40