Using print command recursively.

I have a code with a for loop. In each iteration I need to print the results in a file. How can I use the printed results of previous iteration in the current iteration. Suppose that for the first iteration I have:

fprintf('f(%d) is %fI(x>f)',t,a(t),b(t));

which gives me:

f(1) is 0.6931I(x<3.5000)

Now for the second iteration my f(2) is f(1)+sth. Instead of writing

fprintf('f(%d) is %fI(x>%f)+%fI(x>%f)',t,a(t-1),b(t-1),a(t),b(t));

can I save my previous print as a variable called 'pre_f' and call it in my new fprintf command? for example:

fprintf('f(%d) is %?+%fI(x>%f)',t,pre_f,a(t),b(t));

Answer 1

[Fangjun Jiang]

use sprintf() to print to a variable of string.

pre_f=sprintf('f(%d) is %fI(x>f)',t,a(t),b(t));

use %s to print a string.

NewString=sprintf('Previous string is : %s',pre_f);

What is the purpose of your code?

[Walter Roberson]

And to get the string to appear on the output,

fprintf('%s\n', pre_f);

or

fprintf('%s\n', NewString)

as appropriate.

[Soudeh]

Really thanks Fangjun! It worked for me!

It is a Machine Learning code. In each iteration the results should be printed. Moreover, in each iteration the result is previous result + new part. So imagine for the iteration 20 if you hadn't helped me I must have written all the previous results from 19 iterations.