Tabulate data from loop iterations

I am creating a Newton-Raphson method code to create a table to display the x value and delta x value. This is my code so far. Although it works as is, I would like the loop to only run while delta_x is <= -0.001. Right now I am hard coding the number of iterations. Also, how can I add colum headers to the displayed table?

clc;
clear all;

x = 5;
i = 0;
T = table;
Table = zeros(9, 3);
for i = 1:10
    
    x_new = x;
    delta_x = -(x.^4 - 5*x.^3 + 9*x + 3)./(4*x.^3 - 15*x.^2 + 9);
    x = x + delta_x;
    
    Table(i, :, :) = [i delta_x x_new];
    fprintf('%d   %.4f    %.4f\n',Table(i, :, :));
    
    i = i + 1;
    
    
end

<<
1   -0.3582    5.0000
2   -0.1042    4.6418
3   -0.0086    4.5375
4   -0.0001    4.5290
5   -0.0000    4.5289
6   -0.0000    4.5289
7   -0.0000    4.5289
8   -0.0000    4.5289
9   -0.0000    4.5289
10   -0.0000    4.5289

[Stephen23]

"I would like the loop to only run while delta_x is <= -0.001"

Use a while loop.

[Jonathan Lowe]

This code gives me the desired output and stops corectly. However, the method I used to generate a table is not working. How can I formulate this into a table?

fprintf('%s %10s %8s\n', 'i', 'delta_x', 'x_new')
x = -5;
i = 0;
T = table;
Table = zeros(9, 3);
delta_x = -(x.^4 - 5*x.^3 + 9*x + 3)./(4*x.^3 - 15*x.^2 + 9);
while abs((delta_x)) >= 0.0001
    
    x_new = x;
    delta_x = -(x.^4 - 5*x.^3 + 9*x + 3)./(4*x.^3 - 15*x.^2 + 9)
    x = x + delta_x
    
    %Table(i, :, :) = [i delta_x x_new];
    %fprintf('%d   %.4f    %.4f\n',Table(i, :, :));
    i = i + 1;    
end

Answer 1

[Walter Roberson]

Do not use %d by itself for this purpose: use %Nd where N is a number. For example %15d .

For the headers you would use things like

fprintf('%3s %15s %15s\n', 'i', 'delta_x', 'x_new')

[Jonathan Lowe]

I appreciate the input, however it does not provide input for the question asked about stoping the loop via delta_x and table headers

[Walter Roberson]

You cannot stop a loop by table headers.

The fprintf() statement I gave showed how to create table headers for display output.

To stop a loop when delta_x exceeds -0.0001 then

while delta_x < -0.0001

Are you sure you do not want to stop when abs(delta_x) becomes less than 0.0001 ?

[Jonathan Lowe]

I apologize, my wording of that was confusing, did not mean to imply I wanted to stop the loop via table headers. Knowing I need to use a while loop, I must predefine delta_x for it to work, however delta_x isnt defined until inside the loop. How can I implement this? (I am fairly new to loop structures)

[Walter Roberson]

while true
    ....
    calculate delta_x
    if delta_x satisfies some condition
        break
    end
end