Getting Error ''Function 'subsindex' is not defined for values of class 'function_handle'."

Please help, I am getting the above error when I am trying to input a function handle into another function. My code calling the function is as follows : a,b,c, and d are defined and have values. I do not understand what is wrong here. Thanks in advance.

[madhan ravi]

upload your code picture won't help

[Steven Lord]

BTW your if statement, in the absence of any limitations on a and d, is not generally true.

Let a = -1, b = 1, c = 0, d = 0.5. d is greater than a, but the plot created by the code below clearly crosses y = 0 near x = 1 and x = -1.

>> f = @(x) -cos(x)+0.5;
>> fplot(f)

fzero confirms that f has a zero.

>> r = fzero(f, 0)

Let's plot the zero and check.

>> hold on
>> plot(r, f(r), 'ro')
>> yline(0);

Answer 1

[Walter Roberson]

you define Newton_Raphson as a variable , the result of ismember . But then you have

Newton_Raphson(y)

which asks to index the array using the function handle y as the index .

I have no idea what your intent is.