Iteration Problem

[libero30]

Hello, I'm trying to write a code to help understand a project (this isn't for a specific assignment). I've got an iteration problem, there are two scenarios in my program:

1. The variable needs to be increased to find the solution
2. The variable needs to be decreased to find the solution

The problem I have is that I cannot think of a way to enter statements so that only one of the above iterative loops is carried out. At the moment as soon as the variable crosses 0 there is an oscillation as the program flicks between the values and I have to terminate the program. I know that there is a way to set true/false statements but I haven't found a way to do this without the value being reset when the loop goes back to the start.

Here's part of the code without the formulae:

if (n_e-n_e_new < 0)                /*If n_e is too big then decrease n_e CHANGE CONDITION*/
                {
                    n_e *= 0.5;
                }
 
                else
                {
                    n_e *= 1.5 ;
}
 

Thanks for any help you might have.

[weaknessforcats]

Generally speaking, you cannot use the integer operators ( <, >, <=, ==, etc) with floating point. You are apparently trying nto get this to work for a double.

What happens is that due ot the aautomatic rounding, values close to the ones being tested may report true when they aren't.

Google for Floating Point Arithmetic or read IEEE 754 standard specification for details.

To compare two floating point numbers, you have to establish a sigma error tolerance.

if (fabs(i - j) < 0.000001) { ... // almost equal }