Community Profile # Simone A.

### Department DICEA | Sapienza University of Rome - Department of Earth Sciences | University of Turin

Last seen: 3 days ago Active since 2022

Programming Languages:
R, MATLAB
Spoken Languages:
English, Italian, Spanish
Professional Interests:
Earth and Planetary Science

#### Statistics

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Question

Draw a curve defining the bounds of a scatter plot to detect anomalous (sparse or low density) points
Dear all, I have thousands of x,y data paris of observed and theoretical temperatures in a given region, where I need to identif...

21 days ago | 2 answers | 1

### 2

Question

Detect datapoints deviating from the main, curved, cluster. Outlier detection
Dear all, I need to identify some anomalous data points in my data. I have thousands of them, so I need to automatise the proces...

26 days ago | 1 answer | 0

### 1

Question

How can I obtain all possible combinations of 3 decimals whose sum equals 1, without running into memory and space issues?
Hi all, I am trying to obtain all possible combinations for 4 identical vectors (v1, v2, v3, and v4) whose sum equals 1. v1 =...

3 months ago | 4 answers | 0

### 4

Question

Help creating an array with uniformly distributed random numbers (row-wise) comprised between 0 and 1, with each column having a sum of 1
Hi All, I am trying to solve this problem, but I am not even sure this is possible. I need to run a model 1e8+ times. To do th...

3 months ago | 2 answers | 0

### 2

Question

Detect clouds in IR images, taking a cloud-free scene as a reference
Dear all, I am trying to detect clouds in my infrared satellite scenes. I have a reference cloud-free image which I believe mig...

4 months ago | 1 answer | 0

### 1

Question

How to obtain Curl and Divergence of a matrix?
Dear all, I have got a matrix (let's call it M, M=100x100). I am trying to obtain both divergence and curl. So far, I m...

5 months ago | 1 answer | 0

### 1

Question

[Image Analysis] Detect bright targets in images by gradient direction and intensity patterns (or any other applicable approach)
Dear all, I have tried quite a lot of approaches, but I still couldn't find something that actually works consistently accross ...

5 months ago | 1 answer | 0

### 1

Question

Image Processing - Absolute sum of the differences employing a weighted kernel
Dear all, I hope you can help. I am trying to replicate an alghoritm (for target detection) found in a research paper: https:...

5 months ago | 1 answer | 0

### 1

Question

Interpolate to fill missing values in a temperature Matrix by considering the altitude (stored in a separate matrix)
Dear all, I have got a matrix with temperatures (let's call it T), and a matrix with altitudes (let's call it Z). They're both ...

5 months ago | 1 answer | 0

### 1

Question

Help increasing the speed of a piece of code
Dear all, Plain summary: I have a temperature matrix and I need to find the average temperature of the 8 pixels surrounding e...

6 months ago | 2 answers | 0

### 2

Question

Help improving speed of this code/loop
Dear all, I wrote the code below, which does exactly what I need. Basically, I have several (10.000+) 134x134 matrices (images)...

6 months ago | 1 answer | 0

### 1

Question

Average of the surrounding pixels for each 3x3 matrix, excluding the "outliers" from the count.
Dear all, I ve got several 134x134 double class temperature data matrices. For each pixel, I need to calculate the average of ...

6 months ago | 1 answer | 0

### 1

Question

Unclear periodicity output with daily temperature dataset using periodogram
Dear all, I am struggling to find a meaningful periodicity of my dataset. Your help would be much appreciated. I have a dataset...

8 months ago | 2 answers | 0

### 2

Question

Extract area of matrices (lat, lon, data) by shapefile. "Requested array exceeds the maximum possible variable size."
Hi all, I've got 3 matrices, lat, lon, data (8000 X 8192 each) and one shapefile (80 X 1 struct, attached). I need to extrac...

8 months ago | 1 answer | 0

### 1

Question

(Re-)create a matrix of latitude and one of longitude knowing the 4 vertices , taking into account the earth curvature
Dear all, I wonder if the below can be implemented in MATLAB (or at all). I have got a satellite image (Z). Z is a matrix of...

8 months ago | 1 answer | 0

### 1

Question

Custom Matrix Interpolation for every 10 numbers in each column
Dear all, I've got a matrix (Mx) 400 x 410. I need to interpolate it to obtain a 2000x2050 matrix. The final result should be al...

8 months ago | 2 answers | 0

### 2

Question

Exclude central pixel from sliding mean calculation of surrounding pixels in a matrix
I have got a matrix (M) where I need to calculate the average of the surrounding (3x3) pixels for each pixel, excluding the cent...

8 months ago | 1 answer | 0

### 1

Question

Loop to Identify changes/steps for each column of a matrix
Dear all, I've got a matrix, let's call it M. What I need to do, is to identify all of the values, for each column, that are ...

9 months ago | 1 answer | 0

### 1

Question

Identify, for each column of a matrix, numbers that are smaller than the previous ones, creating a 0 1 output having the same size of the original matrix
Dear all, I've got a matrix, let's call it M. M = 1000x1200 The first 3 columns of M look like: 1.05 21.22 17.2 ... 2.01...

9 months ago | 1 answer | 0

### 1

Question

Matlab code contains comments with strange/unrecognisable characters. Can these be "translated" in English?
Dear all, I am currently evaluating this code, available from https://it.mathworks.com/matlabcentral/fileexchange/116570-pre-pr...

9 months ago | 2 answers | 0