Summation Notation: Is \sum_{u,v} Equal to \sum_u\sum_v?

In summary, the two expressions \sum_{u,v} H_{i-u,j-v}F_{u,v} and \sum_u\sum_v H_{i-u,j-v}F_{u,v} are the same, assuming that the ranges of the indices are unambiguous. The first form may be written in a textbook or other context to save space.
  • #1
gnome
1,041
1
Is

[tex]\sum_{u,v} H_{i-u,j-v}F_{u,v}[/tex]

the same as

[tex]\sum_u\sum_v H_{i-u,j-v}F_{u,v}[/tex]

?

(Don't worry about what H,F,i,j,u,v are. I'm only asking about the notation.)
 
Last edited:
Mathematics news on Phys.org
  • #2
I only see this in the case that there could be no confusion about the range of the indicies, and so I would say yes, they are the same.
 
  • #3
Yes, thanks, assuming that the ranges of the indices are unambiguous...

I read the first form in a textbook; the context is applying convolution to image data, and I don't see any way to interpret it other than as a double summation. I just wanted some reassurance that I'm not overlooking something.
 
  • #4
It's written that way to save space. Similar to writing [tex]\int f \, dV [/tex] rather than [tex]\int \int \int f \, dx\, dy\, dz [/tex]
 

1. What is summation notation and how is it used in mathematics?

Summation notation, also known as sigma notation, is a way to express a series of terms in a compact and efficient manner. It is commonly used in mathematics to represent the sum of a sequence of numbers or other mathematical objects.

2. Can summation notation be used to represent multiple sums?

Yes, summation notation can be used to represent multiple sums. This is known as double summation or nested summation. It involves summing over two or more variables simultaneously, with each variable having its own range of values.

3. Is \sum_{u,v} equal to \sum_u\sum_v?

Yes, \sum_{u,v} is equal to \sum_u\sum_v. Both notations represent double summation and are used interchangeably in mathematics. The choice of notation is typically based on personal preference or the context of the problem.

4. What are the benefits of using summation notation over writing out each term?

Using summation notation can provide a more concise and efficient way to represent a series of terms. It also allows for easier manipulation and generalization of formulas involving sums. Additionally, it can help to avoid errors and make complex mathematical expressions easier to read and understand.

5. Can summation notation be used to represent infinite sums?

Yes, summation notation can be used to represent infinite sums, also known as series. In this case, the range of values for the variable will be from 1 to infinity. However, these types of sums require further analysis to determine if they converge or diverge.

Similar threads

  • General Math
Replies
5
Views
2K
  • General Math
Replies
9
Views
1K
  • General Math
Replies
4
Views
1K
  • Linear and Abstract Algebra
Replies
12
Views
1K
Replies
6
Views
1K
  • Classical Physics
Replies
4
Views
522
Replies
16
Views
3K
Replies
3
Views
708
  • Special and General Relativity
Replies
1
Views
673
  • Calculus and Beyond Homework Help
Replies
0
Views
441
Back
Top