# Tag Info

Accepted

Grid ...
• 396k

### How to align images?

Using ImageFeatureTrack works pretty well: ...
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Accepted

### CorrelationTest vs PearsonCorrelationTest

Update: Added at the end what happens when the tests for normality have small P-values. The difference in the results of the two functions is not due to considering different null hypotheses. They ...
• 41.7k
Accepted

### How to align images?

My solution is the following: Determine the shift between both images: ...
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• 6,057

• 10.2k
Accepted

### Confusion about the correlation coefficient

You are confusing a particular sample of size 1 ({x,1-x}) and the bivariate random variable $(X, 1-X)$ where $X\sim U(0,1)$. Also, your use of ...
• 41.7k

### Nonlinear experimental data fit without initial parameters

The main issue is that you haven't programmed your model correctly. In your theoretical model you have $|\tau|$ but in the Mathematica code you don't have the absolute value. Making that change and ...
• 41.7k
Accepted

### Partial and semipartial correlation

Mathematica has a PartialCorrelation function but that is for time series data. However by following the information in Partial and semipartial correlation you can ...
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### quantifying striations in XY plot

While I agree with @J.M. that asking on the stats site would be a good idea, I thought I'd have a go anyway. But be warned: I'm no statistician. The basic idea is that if you can project the data ...
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Accepted

### Numerics & List Manipulation:ListCorrelate: yield $\{-f1 + f2, \dots, -f2 + f4, \dots\}$ from $\{f1, f2, f3, f4, f5\}$

ListCorrelate[{-1, 0, 1}, {f1, f2, f3, f4, f5}, {2, 2}, "Fixed"] {-f1 + f2, -f1 + f3, -f2 + f4, -f3 + f5, -f4 + f5}
• 396k
Accepted

### MATLAB to Mathematica CorrelationMatrix implementation

That was already a very good start. I take your function and modify it only slightly. I anticipate from the Matlab code that not the indices but the maturities ...

### Revealing correlation between one parameter and set of parameters.

If you can build a classifier for your data, e.g. $$F : \{p^k_1,p^k_2,...,p^k_{10}\} \longrightarrow P_i ,$$ then you can use the approach described in this discussion: "How can I determine the ...
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### Determining Which Pattern Correlates with Each Sublist The Most

I apologize if I have misunderstood the aim. In the following are two approaches. The first uses absolute correlation as distance function to generate a distance matrix and the major diagonal is ...
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### MATLAB to Mathematica CorrelationMatrix implementation

Starting from Henrik's implementation of corrFunc[], I have managed to shorten it slightly (after correcting a sign mistake): ...
Accepted

### Stochastic process: Understanding Ornstein Uhlenbeck Process

You have different x axes. For the correlation function the x axis is 0,1,2,... And for the Table you have 0,0.1,0.2,0.3,... (Note: f is not defined, I set it to f=0.1) If we change the x axis of the ...
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### Autocorrelated random field generation

As noted by @mikado generating the random sample directly is more than a bit sluggish. If you have something on the order of 10,000 points (a 100 x 100 array), then the following code is simple and ...
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### Expectation of correlated variables

It's not different behavior. When you use Expectation[s1*s2,{s1\[Distributed]S1,s2\[Distributed]S2}] the documentation states that you are assuming that ...
• 41.7k
Accepted

### Speed up computation of a correlation matrix

m = RandomInteger[40, {10000, 40}]; (a = N[Correlation[m]]) // Timing // First (b = Correlation[N@m]) // Timing // First 5616.29 0.0468003 10^5 time ...
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### Correlation Matrix Not Working on All Numerical Dataset

Correlation is not tuned to take Dataset but there are ways to calculate. With ...
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Accepted

Perhaps ...
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### Caclulate second partial derivatives of a numerically defined function

There is a package called NumericalCalculus which has a function ND, which takes a numerical derivative. This is a bit odd (to ...
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### Eigensystem for simple equi-correlation matrix

Eigensystem does not orthonormalize the eigenvectors if the matrix consists only of exact input. What worses the situation in this case is that there is an ...

### Wrong definition of auto-correlation function(ACF)

Update: My original answer which constructed the estimate of the sum of all of the correlations one-at-a-time was much, much slower than the method provided by the OP. (I should have followed the ...
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Accepted

### Correlation test for $x$ and $y$ values of a list

What you want for a correlation test is CorrelationTest[data, Automatic, "TestDataTable"] ListPlot[data] The $p$-value indicates that, were you to pick ...
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### How to generate a random matrix with arbitrary correlation between elements?

Simplify $ij\to u$ and $kl\to v$: find $M_u$ such that $\langle M_u\rangle=0$ and $\langle M_u M_v\rangle=\tau_{u v}$. This notation makes the analysis a bit simpler. We can achieve this effect by ...
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Accepted

### Correlated random field generation

I'm not sure what you mean by "correlated" in "correlated gaussian random fields" but you can generate two independent fields and then compare the first with the sum of the first ...
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### Probability of a point being from the same distribution as sample

Expanding the above comment: Let's assume that we have a sample of 2D points, generated here at random (fill in your points instead): ...
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1 vote

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1 vote

### Problem with tracing a marker in an image

The reason that the marker image changes is because of the different coordinate origins used by ImageTake and PixelValuePositions...
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