Error solving transcendental function

E-e*sin(E)-M=0

I'm attempting to solve this equation for E and plot E vs. M (varying from 0 to 2pi) while e=[0:0.25:1]

Here's my code:

function output=kepler(M,e)
M=[0:(2*pi)/4:2*pi]
e=[0:0.25:1]
n=0
while n<length(e)
    n=n+1
    m=0
    while m<length(M)
    m=m+1
    Eroot(M,e)=fzero(@(E)(E-e*sin(E)-M),M(m))
    end
end

Here are the errors I get:

Operands to the || and && operators must be
convertible to logical scalar values.

Error in fzero (line 308)
    elseif ~isfinite(fx) || ~isreal(fx)

Error in kepler (line 14)
    Eroot(M,e)=fzero(@(E)(E-e*sin(E)-M),M(m))

I know I haven't even attempted to plot my answers yet but I really need to solve for E first and am really struggling.

HELP!

Answer 1

[Steven Lord]

FZERO solves one equation in one unknown. By using vectors e and M in the anonymous function you pass into FZERO, you're essentially giving it many equations in one unknown.

Even if you solve this by using loops over e and M and solving for each individual element of e and M you're going to run into a problem. Both e and M contain values that are unsuitable to use as matrix indices, but you're using them as indices into Eroot. You will need to fix that.