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43 views

### Sum up different arrays into a new array

I have a question regarding sums in arrays. So I have the following array: ...
804 views

### How to speed up large double sums in a table?

I am calculating a 3-by-3 matrix whose elements are given as follows: $$M_{mn} = \frac{1}{N}\sum_{i=1}^N \sum_{j=1}^N (r^i_m - r^j_m)(r^i_n - r^j_n) \tag{1}$$ where $N$ is the total number of ...
86 views

### Create and manipulate list with variable length?

Is there a way to create and manipulate a function of a sum of arbitrary length? Specifically, I'd like to create a function like the following: ...
142 views

### Cumulative total of columns in a matrix or table

I have the following: matrix1 = {{a, b, c, d}, {e, f, g, h}, {i, j, k, l}, {m, n, o, p}} (Note that it's the data that matters, not the fact it's defined as a ...
50 views

### Summing results of a table

I have a simple table: example1 = Table[N[x^(x/r), 5], {r, 1, 10}, {x, 1, 10}] I want to create a new table ...
206 views

### How to correctly implement in a new function the scoping behavior of Table, Sum and other commands that use Block to localize iterators?

It is documented that "Block is automatically used to localize values of iterators in iteration constructs such as Do, Sum, and Table." Therefore the dummy index (iterator) in a Sum is shielded ...
108 views

### Accessing the elements in a table is slower than calculating each time?

This is a follow-up of How to accelerate combinations and sum calculations here? I have tried all tricks but when N reaches 35 the time is still intimidating in a 16-core server, which is far better ...
33 views

### Partial Sum of Binary Sequence not Working

I have the following code: ...
460 views

### How to increase the evaluation speed of this somewhat complicated table / matrix operation?

I'd like to calculate the following one-dimensional array: OneDimArray = Table[(Norm[Sum[ MatrixA[[i,j]]VectorB[[j]],{j,N}]])^2,{i,N}] However this takes a very ...
112 views

### tabulating summation series with restrictions

Trying to solve this question for a good 5 hours but remained stuck. My intuition tells me I am missing something trivial that I've overlooked or forgotten. I am restricted only to the function 'table'...