is:Conversion to logical form function_handle is not possible.

Hi I want to do a comparison with function handle. For example : Fun2=@(x) (4*x+1) While @(x)Fun2(x) >3 do something

The error is:Conversion to logical form function_handle is not possible. Thank a lot

Answer 1

[Walter Roberson]

while Fun2(x) > 3

and be sure to update x inside the loop

[Tara Behmanesh]

Thanks it worked.but now another error occurs: undefined function or variable 'a'. The code is attached

[Walter Roberson]

The message is correct. You do not define a or b before you try to use them in

while fun2(e,a,b)>10^(-6)||fun2(e,a,b)<-10^(-6)

Reminder: when you use

    fun1=@(a,b)(b-a)./2;

then that does not define variables a or b: it defines only fun1 and it defines fun1 as being an anonymous function that accepts two positional parameters that for convenience are referred to as a and b.

    fun1=@(a,b)(b-a)./2;

is coded sort of like

    struct( 'formula', #(_Parameter{2}-_Parameter{1})./2)# , 'ParameterNames', {'a', 'b'})

in the sense that the execution of the code depends only on parameter position and the names of the parameters are (nearly) only used for display purposes.