Submitted

Multiple eigen-values for 2x2 and 3x3 matrices

Compute in one shot the eigen-values of multiples (3 x 3) matrices using Cardan's formula

15 días ago | 12 downloads |

Submitted

MultipleQR

Perform a bunch of QR factorization of same size matrix

15 días ago | 4 downloads |

Answered

How to put a spline through points representing a path

Put this next-below to your code waypoints=unique(waypoints,'rows','stable'); % <- this is required because your example as dup...

How to put a spline through points representing a path

Put this next-below to your code waypoints=unique(waypoints,'rows','stable'); % <- this is required because your example as dup...

17 días ago | 1

| accepted

Answered

Extract first and last nonzero elemenents inside subarrays avoiding mat2cell

A = [0 0 1 2 0 5 0 0 6 0 3 0 ; 0 3 0 2 6 0 0 0 0 0 0 0]; b = reshape(A.',6,[]) ~= 0; [m,n] = size(b); [~,istart] = max(b,[]...

Extract first and last nonzero elemenents inside subarrays avoiding mat2cell

A = [0 0 1 2 0 5 0 0 6 0 3 0 ; 0 3 0 2 6 0 0 0 0 0 0 0]; b = reshape(A.',6,[]) ~= 0; [m,n] = size(b); [~,istart] = max(b,[]...

19 días ago | 0

| accepted

Answered

how to generate permutations of N numbers in K positions

No loop, no extrenal file needed N=5; K=3; P=nchoosek(1:N,K); P=reshape(P(:,perms(1:K)),[],K) You might further sort the p...

how to generate permutations of N numbers in K positions

No loop, no extrenal file needed N=5; K=3; P=nchoosek(1:N,K); P=reshape(P(:,perms(1:K)),[],K) You might further sort the p...

19 días ago | 1

Answered

How to generate this matrix?

>> rho=rand rho = 0.8832 >> N=4 N = 4 >> a=rho.^(0:N-1); >> M=toeplitz(a,a) M = 1.0000 ...

How to generate this matrix?

>> rho=rand rho = 0.8832 >> N=4 N = 4 >> a=rho.^(0:N-1); >> M=toeplitz(a,a) M = 1.0000 ...

20 días ago | 0

| accepted

Answered

Roots of a sixth order polynomial in symbolic form

"Ok let me elaborate a bit further. I have a system with a sixth order denominator polynomial, like i mentioned in the question....

Roots of a sixth order polynomial in symbolic form

"Ok let me elaborate a bit further. I have a system with a sixth order denominator polynomial, like i mentioned in the question....

22 días ago | 0

| accepted

Answered

How to vectorize A\B operation on slices of 3D matrices?

Yes there is new news since I post this MultipleQR fex (MEX required, OpenMP multithreading), for 6 x 6 this is the speed up on ...

How to vectorize A\B operation on slices of 3D matrices?

Yes there is new news since I post this MultipleQR fex (MEX required, OpenMP multithreading), for 6 x 6 this is the speed up on ...

23 días ago | 1

Answered

Determine polynomial coefficients so that it's roots lie on the unit circle

For P(z) = a*z^2 + b*z + c; I claim this is these two conditions are equivalent to the fact that P has two roots on unit circ...

Determine polynomial coefficients so that it's roots lie on the unit circle

For P(z) = a*z^2 + b*z + c; I claim this is these two conditions are equivalent to the fact that P has two roots on unit circ...

25 días ago | 1

Answered

Readability of matlab code

Why not use object oriented programing? Put your external parameters in properties. Put your functions as methods. Implement an...

Readability of matlab code

Why not use object oriented programing? Put your external parameters in properties. Put your functions as methods. Implement an...

alrededor de 1 mes ago | 0

Answered

Piecewise differentiation, automatic identification of pieces

https://www.mathworks.com/matlabcentral/answers/587987-linear-segmentation-of-noisy-data?s_tid=ta_ans_results

Piecewise differentiation, automatic identification of pieces

https://www.mathworks.com/matlabcentral/answers/587987-linear-segmentation-of-noisy-data?s_tid=ta_ans_results

alrededor de 1 mes ago | 2

Submitted

Random derangement

Generate sequences of random derangement

alrededor de 1 mes ago | 3 downloads |

Answered

Why Contour matrix M ( [M,c] = contour(__) ) contains the data points exceeding xmax/ymax?

[M,h]=contourf(f,8) Return contours of 8 levels, not single level of value 8. You might use this function to decode the output...

Why Contour matrix M ( [M,c] = contour(__) ) contains the data points exceeding xmax/ymax?

[M,h]=contourf(f,8) Return contours of 8 levels, not single level of value 8. You might use this function to decode the output...

alrededor de 1 mes ago | 0

| accepted

Answered

What frustrates you about MATLAB? #2

Some time data comes as single, but text just rejects it >> x=single(0); >> y=single(0); >> text(x,y,'Why single is not suppo...

What frustrates you about MATLAB? #2

Some time data comes as single, but text just rejects it >> x=single(0); >> y=single(0); >> text(x,y,'Why single is not suppo...

alrededor de 1 mes ago | 1

Answered

How can I get randperm to return a permutation of a vector that has no entries at their original positions?

Here is an implementation of a non-rejection method and unbiased random derangement: function p = randder(n) % p = randder(n) ...

How can I get randperm to return a permutation of a vector that has no entries at their original positions?

Here is an implementation of a non-rejection method and unbiased random derangement: function p = randder(n) % p = randder(n) ...

alrededor de 1 mes ago | 2

Answered

matrix in special arrangment for cycler gemetry

>> A=[11 12 13 14 15] A = 11 12 13 14 15 >> toeplitz(A,A) ans = 11 12 13 14 15 ...

matrix in special arrangment for cycler gemetry

>> A=[11 12 13 14 15] A = 11 12 13 14 15 >> toeplitz(A,A) ans = 11 12 13 14 15 ...

alrededor de 1 mes ago | 0

| accepted

Answered

how matlab stores graphics objects?

All graphic objects are class "handle". Handles is a identify to designate the object and it's obviously 8 bytes as showed by wh...

how matlab stores graphics objects?

All graphic objects are class "handle". Handles is a identify to designate the object and it's obviously 8 bytes as showed by wh...

alrededor de 1 mes ago | 0

Answered

speeding up my for loop

function y=divisors2(N) f = factor(N); [~,~,J] = unique(f); n = accumarray(J,1); y = prod(n+1); end Test >> N=27022021 ...

speeding up my for loop

function y=divisors2(N) f = factor(N); [~,~,J] = unique(f); n = accumarray(J,1); y = prod(n+1); end Test >> N=27022021 ...

alrededor de 1 mes ago | 1

| accepted

Answered

Check if nullspace is contained in another + finding intersection of 2 nullspaces.

First question: KA = null(A); KB = null(B); % Check span KA is included in span KB PKA = KB*(KB'*KA); % Projection KA on ...

Check if nullspace is contained in another + finding intersection of 2 nullspaces.

First question: KA = null(A); KB = null(B); % Check span KA is included in span KB PKA = KB*(KB'*KA); % Projection KA on ...

alrededor de 1 mes ago | 1

Answered

How can I get randperm to return a permutation of a vector that has no entries at their original positions?

This will do what you ask for https://www.mathworks.com/matlabcentral/fileexchange/30189-randpermfull?s_tid=srchtitle Even bet...

How can I get randperm to return a permutation of a vector that has no entries at their original positions?

This will do what you ask for https://www.mathworks.com/matlabcentral/fileexchange/30189-randpermfull?s_tid=srchtitle Even bet...

alrededor de 1 mes ago | 0

| accepted

Answered

Theory of Bicubic interpolation

It has been answered here https://www.mathworks.com/matlabcentral/answers/78116-algorithm-of-bicubic-interpolation In 2D you d...

Theory of Bicubic interpolation

It has been answered here https://www.mathworks.com/matlabcentral/answers/78116-algorithm-of-bicubic-interpolation In 2D you d...

alrededor de 2 meses ago | 0

Submitted

Free-knot spline approximation

Least squares approximation of 1D data using free-knots spline

alrededor de 2 meses ago | 29 downloads |

Answered

Finding LAT LONG inside a circle of a given LAT LONG .

% Random data lonA=rand*360; latA=rand*180-90; n = 10000; lonP=rand(1,n)*360; latP=rand(1,n)*180-90; earthradius = 6357;...

Finding LAT LONG inside a circle of a given LAT LONG .

% Random data lonA=rand*360; latA=rand*180-90; n = 10000; lonP=rand(1,n)*360; latP=rand(1,n)*180-90; earthradius = 6357;...

alrededor de 2 meses ago | 0

| accepted

Answered

HELP. Need to understand MATH behind scatteredInterpolant or Interp2 function

"Based on the equation that I had in that screen shot would you assume that the other model is using a simplified linear interpo...

HELP. Need to understand MATH behind scatteredInterpolant or Interp2 function

"Based on the equation that I had in that screen shot would you assume that the other model is using a simplified linear interpo...

alrededor de 2 meses ago | 0

| accepted

Answered

How to generate a nearly symmetric matrix?

Just generate first a symettric matrix then perturb a "the overwhelming minority" of elements. Whatever that definnition means....

How to generate a nearly symmetric matrix?

Just generate first a symettric matrix then perturb a "the overwhelming minority" of elements. Whatever that definnition means....

alrededor de 2 meses ago | 1

| accepted

Answered

HELP. Need to understand MATH behind scatteredInterpolant or Interp2 function

Run this, that show the "formula" and how to get zq = -38.5561 zq_check = -38.5561 Code to check 'linear' met...

HELP. Need to understand MATH behind scatteredInterpolant or Interp2 function

Run this, that show the "formula" and how to get zq = -38.5561 zq_check = -38.5561 Code to check 'linear' met...

alrededor de 2 meses ago | 0

Answered

In a vector, how to remove neighbours too close from one another

Using stock function >> uniquetol([1 6 12 17 23 25 34],10,'DataScale',1) ans = 1 12 23 34 Jan's various ...

In a vector, how to remove neighbours too close from one another

Using stock function >> uniquetol([1 6 12 17 23 25 34],10,'DataScale',1) ans = 1 12 23 34 Jan's various ...

alrededor de 2 meses ago | 2

Answered

Generate random integers that sums to a specific number within a specific range

Unfortunately the uniform distribution with bounds for integer is much more challenging. One way is to approximate by rounding t...

Generate random integers that sums to a specific number within a specific range

Unfortunately the uniform distribution with bounds for integer is much more challenging. One way is to approximate by rounding t...

alrededor de 2 meses ago | 0

Answered

How to calculate the pairwise distince between two dataset without any loop

If you have latest MATLAB release (for pagemtimes) and download this Multiple same size solver FEX X = [1 2 1;3 4 2;5 6 3] Y =...

How to calculate the pairwise distince between two dataset without any loop

If you have latest MATLAB release (for pagemtimes) and download this Multiple same size solver FEX X = [1 2 1;3 4 2;5 6 3] Y =...

2 meses ago | 0

| accepted

Answered

How could I separate the geometry data from single stl file contains multiple objects by stlread?

You can use conncomp of the triangulation graph data=stlread('research_stl_read.stl'); s=data.ConnectivityList(:,[1 2]); t=...

How could I separate the geometry data from single stl file contains multiple objects by stlread?

You can use conncomp of the triangulation graph data=stlread('research_stl_read.stl'); s=data.ConnectivityList(:,[1 2]); t=...

2 meses ago | 1

| accepted