IBM Mainframe Forum

i want fibonacci series program in rexx.
since i am just learner that's as an example i want that.

i want complete series for a number which has to be entered by user.

Can you please what you mean by below

i want complete series for a number which has to be entered by user.

As far as I know Fibonacci series is f(x) = f(x-1) + f(x-2) like 0,1,1,2,3,5,8,13,18……….Do you mean one should give two consecutives like 8,13 and the remaining series is generated?

Thanks
Shvndu

no ...
i just want a program for fibonacci series .simple.

Hello,

i just want a program for fibonacci series .simple.

Not until you properly define what you want.

We will not charge extra if you use more keystrokes to explain in more detail

The series can run to infinity and i suspect that is not what is needed. . .

Are you looking for a way to chart the spiral from the series? This would be non-trivial. . .

Keep in mind that you know exactly what you want while we all have different backgrounds and may not interpret your request as you intended.

actually i want to know how the concept of array can be used in rexx.

so as an example i took fibonacci series.e.g for a user entered number say 4 the output should come like 0 1 1 2 3 .

i have already tried to write that code in rexx please tell me that whether this is correct or not.
/* rexx */

parse arg n
last=n-1
x.0=0
x.1=1
do i=2 to last
x.i=x.(i-1) + x.(i-2)
end
do i=0 to last by +1
say x.i
end

Hello,
Is that code working? Please let me know.....

Hi,

The index of a stem needs to be resolved before using it. You cannot have something like X.(I-1). It wouldn't be recognized. You could store I-1 in another variable like J=I-1 just before and then using X.J to access it.

I think it's more fun to resolve these math problems with recursion. Something like the following where we compute the first 35 instances and store them in the array ARR.

/* We go up to that number */
LIMIT = 35

CALL FIBONACCI(LIMIT)

/* List all elements in the array */
DO K=1 TO LIMIT
SAY ARR.K
END
EXIT

FIBONACCI: PROCEDURE EXPOSE ARR.

/* Expose the array ARR so it is updated throughout the calls */
/* CURRENT is the current number being computed */

CURRENT = ARG(1)

/* If DATAYPE is NUM, it means we've already computed that number so we return it */

IF DATATYPE(ARR.CURRENT) = "NUM" THEN RETURN ARR.CURRENT

/* Else, we compute the fibonacci number recursively */

IF CURRENT = 1 | CURRENT = 2 THEN ,
ARR.CURRENT = 1
ELSE ,
ARR.CURRENT = FIBONACCI(CURRENT-2) + FIBONACCI(CURRENT-1)

RETURN ARR.CURRENT

Hello Gilles and welcome to the forum,

Good to "see" you here

Thanks for your code

Hopefully, you will find something useful here.

d

/*REXX*/
SAY "HOW MANY FIB U WANT"
PULL Q
L = Q - 4
SAY "0"
SAY "1"
SAY "1"
SAY "2"
W = 1
T = 2
DO I = 1 TO L
E= W + T
SAY E
W = T
T = E
END
EXIT