Math Forum

Re: problem with append

On 21/01/2013 05:05, Bob Hanlon wrote:
> rr = {};
> For[a = 2, a< 6, a++,
> For[b = 2, b< 6,

hello i am new to mathmatica.i have the following problem if anyone could help.

For[a = 2, a < 6, a++,
For[b = 2, b < 6, b++,

In[5]:= rr={};For[a=2,a<6,a++,For[b=2,b<6,b++,AppendTo[rr,a^b]]]

rr

Out[6]=

The correct name is AppendTo, not Appendto. You should start by defining the empty list rr, and then AppendTo rr consecutively, i.e..
In[4]:=

There are some errors here
1. The function name is AppendTo (with capital T) - Mathematica is case
sensitive
2. Even this would not

Hi Paolo,
I think that you have two errors.
The first is that AppendTo has a capital T
The second is that you need to initialise rr outside

Paolo,

Welcome to Mathematica!

You made two basic errors in your code:

(1) At each pass through the inner loop, rr gets reset

rr = {};
For[a = 2, a < 6, a++,
For[b = 2, b < 6, b++,
AppendTo[rr, a^b]]]

rr

Or

rr = Table[a^b, {a, 2,

maybe this is what you want

rr={};
For[a = 2, a < 6, a++,
For[b = 2, b < 6, b++,
rr = Appendto[rr,