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gianluca


Last seen: 3 months ago Active since 2011

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Reshape a 3D matrix
I have 3 vectors x = [1 2 3]; y = [4 5 6]; z = [7 8 9]; from which I create a meshgrid (I use this 3D mesh to compute some v...

4 years ago | 2 answers | 0

2

answers

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Nested loop problem with the second index
Dear all, the following code does not work well for index j > 1. I have two vectors cpx = 1-by-n and cpy = 1-by-m. I would a ...

4 years ago | 3 answers | 0

3

answers

Question


Operations on a sliding 2D window
Dear all, my question concerns how can I apply some functions to study a subset of data given a dataset of spatial data (X,Y,Z)...

5 years ago | 0 answers | 0

0

answers

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compare two matrix and for the elements in common find the minimum difference between specif fields
Hi all, I've two matrices A and B. In the 1st columns of both, there are non unique numbers representing the serial code, e.g...

7 years ago | 1 answer | 0

1

answer

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Select specified (max) values
Dear all, I've a matrix, e.g.: A = [2 1 1 1440 62 2 6 8; 2 2 1 1882 65 2 7 8; 3 1 1 820 51 2 5 8; 3 2 1 1435 65 2 6 8; ...

7 years ago | 1 answer | 0

1

answer

Question


Insert figure title in multiple plots from a cell array
Hi all, I've a dataset (records from different places) with the site names stored in a cell array, the records are in a matrix w...

7 years ago | 3 answers | 0

3

answers

Question


find the closest value
Hi, I have two matrices. A = [01 105 6; 01 203 12; 02 99 6; 02 306 15]; B = [01 0 0; 01 100 25; 01 200 50; 01 300 75; 0...

8 years ago | 1 answer | 0

1

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Question


compare matrices with different dimension
Hi, A = [100123 1 1 50; 100123 1 2 53; 100123 1 3 55; 100456 2 1 78; 100456 2 2 75; ...

9 years ago | 2 answers | 0

2

answers

Question


how to use accumarray and polyfit
hi, I would perform a simple linear fit on selected data in a large dataset to obtain the intercept and slope values. The data a...

9 years ago | 1 answer | 1

1

answer

Question


operations on large dataset
Hi, I want to apply functions on specific data stored in a table (Matrix). The data are of the form: A = [100123 1 1 2500; ...

9 years ago | 1 answer | 0

1

answer

Question


reshape 3d matrix to obtain a column vector
Hi, I've a 3D Matrix A(3x3x3): A(:,:,1) = [1 2 3; 4 5 6; 7 8 9] A(:,:,2) = [10 11 12; 13 14 15; 16 17 18] A(:,:,...

9 years ago | 1 answer | 0

1

answer

Question


How to set a variable name in a code
Hi, I'm writing a code to make operations on imported external data coming from several measurement sites and plot results. I w...

10 years ago | 1 answer | 0

1

answer

Question


how create a new matrix with values found in an another matrix
Hi, I've the matrix A with dimension (m*n*p). I've found the indexes of the first non-zero elements along the dimension p. Th...

11 years ago | 1 answer | 0

1

answer

Question


Compute values in the nodes of a 3d matrix
Hi, Let S2 a surface below the surface S1, I would to compute values in the nodes below S2, starting from the values computed...

11 years ago | 1 answer | 0

1

answer

Question


Compute values in the nodes of a 3d matrix
Hi, I've to compute values in the nodes of a 3d matrix. The coefficients vary along i and j index (X and Y direction). They v...

11 years ago | 2 answers | 0

2

answers

Question


where is the error?
Hi, running the following script: % Create a data set: x = rand(100,1)*4 - 2; y = rand(100,1)*4 - 2; S = x.*exp(-...

11 years ago | 2 answers | 0

2

answers

Question


find index on 3d matrix
Hi, I've a grid [X,Y,Z] = meshgrid(XI,YI,ZI); where XI = 1:1:4; YI = 1:1:4; ZI = -500:100:5000; and a 3d ...

11 years ago | 1 answer | 0

1

answer

Question


3d mesh and index operations
Hi, I've a 3d grid: [X,Y,Z] = meshgrid(0:250:1000,0:250:1000,0:250:1000); and a surface (in this example a plane): ...

11 years ago | 1 answer | 0

1

answer

Question


criteria to assign physical properties at each nodes of a 3d model
Hi, I'm building a 3d geological model (i.e. two layers). I would assign at each node of the model a physical property (e.g. th...

11 years ago | 0 answers | 0

0

answers

Question


how plot results of a 3d matrix
Hi, I've a meshgrid [X,Y,Z] = meshgrid(0:250:1000,0:250:1000,0:250:1000) and I computed in each node a value of tempe...

11 years ago | 1 answer | 0

1

answer

Question


matrix manipulation
Hi, I've an ASCII file like this 450 1 2 3 4 5 6 7 8 9 10 11 12 13 451 1 2 3 4 5 6 7 8 9 10 11 12 13 452 1 2 3 ...

12 years ago | 1 answer | 0

1

answer

Question


What is it better?
From the computational point of view, is it better one cycle _for_ with following _if_ statements, or several cycles _for_ for e...

12 years ago | 2 answers | 1

2

answers

Answered
index calculations
This script, to compute one-dimensional steady-state conductive geotherm with internal heat source, works. Any advice to improve...

12 years ago | 0

Question


index calculations
Hi, I need to do index calculations. I've a vertical column divided into thin layers, for which properties are considered const...

12 years ago | 2 answers | 0

2

answers

Question


non linear minimization
Hi, I've this function which describes the temperature T vs depth z T(i) = T0 - (H(i).*z(i).^2)./k(i) + ((Q.*z(i))./k(i)...

12 years ago | 1 answer | 0

1

answer

Question


store solutions of a for loop
Hi, this is my M-file named nle.m function F = nle(x,b1,b2) F = [(1-x(1))*x(2)*30+(1-x(1))*(1-x(2))*150-b1; x(1)*189+(1...

12 years ago | 1 answer | 1

1

answer

Question


fsolve
Hi, I'm solving a system of two non linear equations involving the same number of variables. I'm using the command fsolve, so...

12 years ago | 1 answer | 0

1

answer

Question


operations on specific row
Hi, I've a for example a 5x3 matrix 2015 52 7 2015 53 12 2015 54 20 3096 77 7 3096 83 11 and I want apply ...

12 years ago | 1 answer | 0

1

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