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Questions tagged [dot]

The tag has no usage guidance.

0
votes
1answer
31 views

How to plot two functions together when one of them needs to be a series of dots, with common labels and colors?

I have two functions that I want to plot together. I want to plot the non-linear and the linear (NL and L in my code) functions together, but I wish that the NL function is plotted as a series of dots ...
2
votes
4answers
173 views

Dot product result has wrong dimension [closed]

I'm doing a small project and I've encountered a problem while using Mathematica. I should mention that I'm kinda new to this software, so maybe it's just something I haven't grasped yet. Anyway, I ...
3
votes
1answer
69 views

How to change node color in .dot file using pattern matching?

For example I have a dot file that describe a decision tree or binary tree In the file, the color of node is always gold, so I try to change it according the number in ...
0
votes
0answers
18 views

Matrix multiplication Q.W not working - Result=matrix Q . matrix W [duplicate]

When I write the code to do the dot product between two matrices, Mathematica does not compute it: How can I get the right matrix? EDIT Thank you for your willingness.
4
votes
2answers
124 views

Product but with Dot operation [duplicate]

I want to describe a way to express a chain of Dot Product like this: m[13].m[12].m[11].m[10].m[9].m[8].m[7].m[6] Something like ...
4
votes
2answers
187 views

Nested Matrix Dotproduct

For a given matrix M[n] of size $ n\times n $ I want to define the following list of matrix-expressions: ...
1
vote
1answer
53 views

Importing a .dot graph file, and changing vertex label format

I worked out how (one way...) to import a .dot graph format file into Mathematica using ...
3
votes
1answer
74 views

Dot Product of Matrices in NDSolve

How to efficiently solve a system of differential equations involving matrix dot product? The example below is solved extremely fast when the array structure is flattened out. Is there a way to reach ...
1
vote
2answers
373 views

dot product not working [closed]

Im supposed to take the dot product of a function and itself. The matrix is a system of 4 equations defined to be : ...
2
votes
1answer
145 views

Orthogonalize with a custom inner product

Bug introduced in 9.0 or earlier and fixed in 10.0 I was trying to define a custom inner product function for Orthogonalize, and have been getting some odd behaviour. Here's a MWE: I try to compute ...
2
votes
2answers
121 views

Generalized n-fold inner product for tensors, iteration and indexing or built in functions?

I'm very new to Mathematica, and struggling to convert one of the codes I'd written in MATLAB. I am trying to program a function for a generalised inner product between two tensors, that is for ...
0
votes
1answer
437 views

Adding dots to an empty region of space [closed]

I want to add dots to the maze so far I know only how to get one dot on the maze. I don't know if there is way without using coordinates. So it would look like this with the dots added (source: ...
0
votes
0answers
77 views

Expressing the output product using dot

I have an expression of the form Hbar.H where H and Hbar are vectors. How can I get the ...
10
votes
1answer
166 views

TensorReduce and Dot

I'm manipulating abstract tensors with Mathematica. I have a question. With the assumptions $Assumptions = (R | r) ∈ Arrays[{4}]; I can do two operations: ...
3
votes
2answers
196 views

Summing matrix products

I need to compute a double sum over a weighted matrix product: $L[M]=\sum_{i,j}^{N}\Lambda[[i]]\;\omega[[i]].M.\omega^{\dagger}[[j]]$. $\Lambda$ is a list of with N complex values(weights) and $\...
5
votes
3answers
391 views

Bilinear Dot Function

In mathematics the matrix product is a bilinear operation $$ \alpha A \cdot(\beta B + \gamma C) = \alpha\beta ( A \cdot B )+ \alpha \gamma (A\cdot C ), $$ where capital letters denote matrices and ...
4
votes
0answers
659 views

Is it possible to simplify an expression in vector form, which involves crossproduct and dot product?

I often need to simplify expressions involving cross product and dot product, for example: f = Dot[Cross[Cross[p1 - p, e1], Cross[p2 - p, e2]], Cross[p3 - p, e3]] ...
1
vote
1answer
827 views

Using the Norm Function

I am trying to take the norm of a general vector and show that for vectors, v,w, that Norm[v cross w]^2==Norm[v]^2*Norm[w]^2-(v dot w)^2 In Mathematica, here are my steps: ...
1
vote
2answers
299 views

Pulling out a prefactor from a dot product

I have three complicated vectors u, v and w as well as three simple prefactors ...
5
votes
2answers
388 views

Factor out the scalar multiplier for the dot product of 2x2 matrices

If yy and zz are 2x2 Hermitian matrices, is there a way that I can mark them (with a property?) as Hermitian so that Mathematica can assume that it can factor out and simplify scalar multipliers from ...
1
vote
1answer
184 views

Unexpected inefficiency when calculating matrix product by Dot

There is an unexpected inefficiency when I calculate matrix product by Dot. The only relevant part of my code is presented as follows: ...
4
votes
2answers
369 views

Dot product for lists

Suppose we want to get the dot product for the following lists aa and bb, whose elements (a, ...
21
votes
3answers
849 views

Why is calling Dot with many arguments so inefficient?

Say I want to multiply a reasonably large list of symbolic matrices. ...
13
votes
1answer
370 views

Why does partitioning increase Dot execution speed?

I have noticed that multiplying a list of matrices can be significantly sped up by partitioning the list, calculating the product of the partitions matrices, and then multiplying the results. ...
3
votes
1answer
1k views

Draw grid with points

How would I draw a grid with dots on specified intersections? The image below shows the basic idea: If I wanted to label the grid lines with index numbers or letters, how would I do that?