Community Profile # Ulrik William Nash

##### Last seen: 23 days ago
35 total contributions since 2015

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Question

I am running a simulation that in some places consists of functions, which in turn have functions. The end of one of these "bran...

3 months ago | 0 answers | 0

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Question

Lookup-scheme for potentially large n choose k matrices
I am writing a simulation that includes the variables and . These variable serves a part in numerous " choose " calculations. S...

3 months ago | 1 answer | 0

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Question

Pasting large code without forced wrapping
I am trying to paste a very large portion of code, which has been via Mathematica. The problem is that MATLAB breaks the code at...

3 months ago | 0 answers | 0

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Question

Efficient code for obtaining the probability of X or less, when the PDF is known, but the CDF cannot be expressed precisely
I am working on a problem relating to a PDF that I can express precisely, and the related CDF, which I have given up expressing ...

3 months ago | 1 answer | 0

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Question

Use a string as a struct name
In different files, I have a struct. Each struct has the same underlying structure and variable names. But the name of each stru...

4 months ago | 1 answer | 0

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Question

The most efficient way to locate the first 1's in each row of a matrix
I have a potentially large r by c matrix, m, consisting of 1's and 0's. What is the most efficient way create a r by 1 vector, v...

4 months ago | 2 answers | 0

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Find the ID of a specific text in a specific column of a many-columned cell.
dx = find(strcmp(Fundamentals, 'ZYXI'))

6 months ago | 0

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Question

Find the ID of a specific text in a specific column of a many-columned cell.
A simple question, for which a simple, to the point answer has been hard to find. Please see the attached image of my cell. I w...

6 months ago | 1 answer | 0

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Question

Parallel Computing - how to run jobs from clients on servers with the same version.
After submitting a batch, I try to retrieve the computed data using j.fetchOutputs{:} However, the system throws the following...

10 months ago | 1 answer | 0

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Question

Normalizing a sparse matrix so that rows sum to 1
I have the following sparse matrix, which relates to a markov process. The parts of the matrix have been assembled sequentially,...

12 months ago | 1 answer | 0

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Question

randsample([0 1],1,true,[1 - p p]) ..... with p as a vector?
I have the following code that generates a 0 or a 1 depending on the probability p: randsample([0 1],1,true,[1 - p p]) But sup...

1 year ago | 2 answers | 0

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Question

A bug in pearsrnd?
With the following values for mean, std, skewness, and kurtosis, pearsrnd stalls without warning: mean = -9.0000e-08 std = 0...

1 year ago | 1 answer | 0

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Question

Computing the average across columns, while discounting a specific column
What is the best way to compute the simple average across the columns of a matrix, when one of the columns must be completely di...

1 year ago | 2 answers | 0

### 2

Question

Obtaining the significance of coefficients from polyfit
It is a simple matter to obtain the coefficients of a simple linear relationship using polyfit. For example coeff = polyfit(x,y,...

1 year ago | 1 answer | 0

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Question

Why does the set dimensions of my figure change upon saving?
I begin my charting with the following code: x0 = 10; y0 = 10; width = 556; height = 588; set(gcf,'un...

1 year ago | 0 answers | 0

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Question

Using MATLAB to collect and store data from INVESTOPEDIA
I am about to write a script that collects stock price data from INVESTOPEDIA. The data is available free of charge by entering ...

1 year ago | 1 answer | 0

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Question

Drawing random numbers according to a particular scheme
I have a vector, p, and each entry in p is a number between 0 and 1. Moreover, the sum of all entries in p is exactly 1. Another...

1 year ago | 1 answer | 0

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Question

An effiient way to isolate permutations of 0's and 1's that sum to k.
I am working on a problem where I need information about all permutations of n coinflips, where the sum of heads is k. I cou...

1 year ago | 2 answers | 0

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An effiient way to isolate permutations of 0's and 1's that sum to k.
Thank you, Walter Roberson. If I am not mistaken, the following provides the general answer: partitions(k,ones(1,n),1)

1 year ago | 0

Question

The fastest way to create a random network?
I am trying to create a square matrix of 1's and zeros, where 1's represents a communication link and 0's represents a lack of t...

2 years ago | 1 answer | 0

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Question

Is this a bug in max(x)?
I have the following two vectors: a = [0.5 0.6 0.1 0.2 0.2]; b = [0.5 0.4 0.1 0.0 0.0]; and I now define x as their diffe...

2 years ago | 1 answer | 0

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Question

How do I center a double-lined diagram title, interpreted as LaTex?
Why does the following not center the first line of the double-lined diagram title? str_title = {'Line 1';'Line 2'}; title(s...

2 years ago | 2 answers | 0

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Question

m1(m2 == 1), but with dimensions of m1 intact?
I have a matrix of 1's and 0'1, m2. I have another matrix with the same dimensions as m2, containing values (i.e., m1). Of these...

2 years ago | 1 answer | 0

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Question

Removing rows from MyFolderInfo = dir('myfolder') before specific date
Having applied the code: MyFolderInfo = dir('myfolder') ; and having thus created the struct "MyFolderInfo" with 5 fields ...

2 years ago | 1 answer | 0

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Question

How important is the accurate specification of nnz for spalloc?
How important for performance is the accurate specification of nnz for spalloc? And is undershooting worse than overshooting?

2 years ago | 1 answer | 0

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Question

I found the function below on File Exchange developed by Loginatorist, which creates a matrix of permutations of elements with r...

2 years ago | 1 answer | 0

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Question

Out of memory - an alternative to this algorithm?
I am working on Markov Chain problem involving a large, sparse transition matrix. Unfortunately, in generating the transition ma...

2 years ago | 2 answers | 0

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Question

Summing values for duplicate rows and columns
I have a vector of rows, columns, and values that I will use to create a sparse matrix: rows = [1 2 3 1]; columns = [1 1 2 1...

2 years ago | 2 answers | 0

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Question

Updating a matrix based on conditions in other matrixes
I have coded the attached loop to update matrix Lr but I would ideally like to use code that can achieve what the shown loop is ...

2 years ago | 2 answers | 0

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Question

Creating a matrix based on information in a vector and another matrix
Suppose I have a vector of success probabilities, for example: p = [0.5,0.25,0.75] I also have a matrix of outcomes, o, w...

2 years ago | 1 answer | 0