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### How to understand the extensional usage of Flatten? [duplicate]

Recently, I have been reading Mathematica program that written by many advanced Mathematica user, like Mr.Wizard, J.M., Kuba,etc to improve my programming capacity In the On generalizing Partition[] (...
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### Levels: how do they work?

I cannot understand how Mathematica manages levels, and so it's always a painful try-and-fail to use Flatten. Can someone please give me a very clear definition? ...
1k views

### Equating matrices (or higher order tensors) element-wise

Say I have two matrices (or, as in my case, higher order tensors) $A,B$, and I want to solve the equation $A=B$. To do so , I need a list of equations that equate entry-wise the elements of $A$ and $B$...
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### Transpose uneven lists

Is there a quick method to transpose uneven lists without conditionals? With: Drop[Table[q, {10}], #] & /@ Range[10] Thus the first list would have the ...
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### Best way to create symmetric matrices

From time to time I need to generate symmetric matrices with relatively expensive cost of element evaluation. Most frequently these are Gram matrices where elements are $L_2$ dot products. Here are ...
629 views

### Prepend 0 to sublists

My question is similar to this one, but my goal is to prepend a single 0 the each sublist, not incrementally many 0's. The file I'm working is a CSV containing around 50K sublists of length 35. I've ...
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### Ways to compute inner products of tensors

One way to evaluate the following sums is combining Table and Sum: $u_{abcd} = \sum_{e=1}^3 v_{aeb}w_{ced}$ $q_{ab} = \sum_{d,e=1}^3 v_{d e a}w_{deb}$ It will look like ...
859 views

### Using Transpose with a list as the second argument

I'm having difficulty understanding the Transpose function. I know what the transpose of a matrix is, not a problem, and I see that applying the ...
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### How to get Matlab data imported with the same dimensions?

I have some Matlab image data with the following dimensions (output is from Matlab): >> size(im) ans = 86 86 3 45 The data imports just fine ...
202 views

### Transpose two uneven lists [duplicate]

I am trying to plot two lists using the ListPlot command. I need to merge two lists. The two lists I have are: ...
667 views

### Translating MATLAB's cell2mat into Mathematica

How I can define a function in Mathematica such that it acts same as the cell2mat command in MATLAB? Example (in MATLAB): ...
453 views

### How to build a matrix from a set of vectors and other matrices using ArrayFlatten

I want to build a 6 by 3 matrix, from the following: one vector is 3 by 1, then a matrix, which is 3 by 2. These will go to the top 3 rows. Now the bottom 3 rows, I'll have 3 vectors each is 3 by 1. ...
633 views

### Understanding Transpose

It is very likely that it is my lack of math skills that is showing up here. However, I think Transpose is such an important function that I need to master it. So I ...