how can i convert an integer to an array in this function?

 function a=get_array_num(n)

 end

requirments:

1.no loops,if,recurion or logical operatos

2.no num2str or str2num

3.length_of(n)=number of digits in "n" (help function)

i think maybe logspace is useful here...but how?

[Walter Roberson]

That does not define any return value "a".

The only way that you can meaningfully have length(n) be the same as the number of digits in n, is if n is a scalar value (length 1) with a single digit.

[Zaza]

 function r = length_of(n)
     if n < 10
         r = 1 ;
     else
         r = 1 + length_of(n/10) ;
     end
 end

[Image Analyst]

That would mean your "a" (now called "r") is an array of 1 - not really much of an array. Besides - that code uses recursion, which is not allowed.

[Zaza]

"a" is not "r" and vice versa

the function "length_of(n)" is known and can be used in the function "get_array_num(n)"

[Zaza]

true

i forgot to mention that "length_of(n)" is recursive regardless of "get_array_num(n)"

[Walter Roberson]

Why is length_of(0) 1 instead of 0? Why is length_of(-23) 1 instead of 3?

[Zaza]

sorry again

suppose n>0 with no leading zeros

[Jan]

For length_of() the log10 function would be much smarter.

Answer 1

[Image Analyst]

How about

a = zeros(n);

or

a = n * ones(1, 10);

or something similar? There is an infinite variety of arrays you could make that would full those requirements, though requirement #3 is not well explained at all (no idea what it even means).

[Walter Roberson]

I see nothing in the requirements that the output must have any relationship to the input.

[Image Analyst]

True, so there are even more infinite ways to answer. This is so poorly described, even with additional comments, that I don't even know how to help anymore.

[Zaza]

there are no infinite ways to answer and i'm sorry if it's described poorly.

the help function is given and that's it. of course the main function must meet the conditions.

[Walter Roberson]

You have not indicated what the result of the function is to be.

[Zaza]

for example:

n=8427

a=[8 4 2 7]

[Image Analyst]

strN = num2str(n) % Convert to string.
a = strN - '0' % Convert characters to separate numbers.

[Walter Roberson]

num2str() was prohibited in the assignment.

[Image Analyst]

What a stupid requirement. Then use sprintf() as the "loophole":

strN = sprintf('%d',n)
a = strN - '0'

[Zaza]

i read the assigmnet again and it said no use of any functions that convert from numbers to strings and vice versa so i guess it's not legal to use _sprintf() _but thanks anyway

[Walter Roberson]

Perhaps you should post the exact assignment.

[Image Analyst]

I did it in 5 lines with a for loop, rem(), floor(), and finally fliplr() to reverse the last digits.

1. for
2. call rem
3. reassign n
4. end
5. call fliplr

I'm sure you don't want me to just give you the answer outright (because you could be considered as not doing your own work) so give that a try.

[Walter Roberson]

The requirements include 'no loops'

[Image Analyst]

Ha! I give up. Who wants to work like that? I hate it when they say to use MATLAB but don't let you use any of the power of it. I don't see the point. I don't see any way, off the top of my head, to march along the digits of your integer if you can't use strings, loops of any type, or recursion if your integer is of unknown length. Of course if you know it's always 4 digits, then you can just write the contents of the for loop 4 times. Good luck with it though. If something strikes me, I'll post a hint.

[Walter Roberson]

I can do it in one smallish line, once given the length_of function. Loops may have been prohibited but ":" has not been.

[Zaza]

may i have a clue how to do it with the colon operator?

[Jan]

@Zaza: It consumed some time and energy to bring you to post an explicit example. We get some parts of the problem distributed to the question and over several comments. Therefore an efficient answer is impossible.

Please edit the original question and insert all available information. Then show us, what you have tried so far, because of course we are not going to solve your homework: you couldn't submit it anymore without cheating!