# Matt J

Professional Interests: medical image processing, optimization algorithms PLEASE NOTE: I do not read email sent through my author page. Please post questions about FEX submissions in their respective Comments section.

**Statistics**

RANK**6**

of 265.087

REPUTATION**25.356**

CONTRIBUTIONS

**220** Questions

**9.844** Answers

ANSWER ACCEPTANCE **
75.0%
**

VOTES RECEIVED**3.326**

RANK**239** of 18.111

REPUTATION**5.655**

AVERAGE RATING**4.90**

CONTRIBUTIONS**34** Files

DOWNLOADS **309**

ALL TIME DOWNLOADS**47318**

RANK

of 116.185

CONTRIBUTIONS

**0** Problems

**0** Solutions

SCORE**0**

NUMBER OF BADGES**0**

CONTRIBUTIONS**0 Posts**

CONTRIBUTIONS**0** Public Channels

AVERAGE RATING

CONTRIBUTIONS**3** Highlights

AVERAGE NO. OF LIKES**2**

**Content Feed**

Find the key for vector transformation

See Example 2: Optimal Reordering of Points in the Examples tab of https://www.mathworks.com/matlabcentral/fileexchange/52795-c...

alrededor de 2 horas ago | 0

How to create a column vector repeating the same character n times?

and has the same character repeating in each row like 'on'. 'on' contains two characters. Repeating it for N rows would give a...

alrededor de 4 horas ago | 1

| accepted

Removal of the the edges from the node of a graph

You want to remove the edges but keep the node itself? If so, G=rmedge(G,outedges(G,nodeID)) If you want to remove the node an...

alrededor de 4 horas ago | 0

How to obtain and plot perpedicular lines using the gradient of a function

Your plot is correct. The lines just don't look perpendicular because of the plot aspect ratio. x = linspace(-2,1,100)'; y ...

alrededor de 7 horas ago | 0

| accepted

Fit ellipse in 3D space

I am searching for intersection of plane and ellipsoid If that is the ultimate goal, you should just rewrite the ellipsoid equa...

alrededor de 16 horas ago | 0

How can I transparent my gaussian distribution and convert to a transparent ellipse

You can extract the points on the contour lines using tis FEX download https://www.mathworks.com/matlabcentral/fileexchange/740...

alrededor de 20 horas ago | 0

| accepted

Submitted

Further tools for analyzing objects in N-dimensional images

A collection of tools to supplement bwpropfilt, bwareaopen, and the like.

1 día ago | 4 downloads |

How can I remove object in binary image by using a mask

You can use bwlmaskpropfiltn() from this FEX download, https://www.mathworks.com/matlabcentral/fileexchange/90762-further-tools...

1 día ago | 0

How can I include the legends within the for loop and how can I set the xticks in MATLAB?

So, how can I include legends with the for loop instead of writing it outside? You are assuming here that the for loop is the o...

2 días ago | 0

| accepted

Rect function with Array

function [y] = rect(T0, A, t) y= ((t >= -T0/2) & (t <= T0/2)) * A; end

4 días ago | 0

| accepted

Count the occurrence of each element in an array

string = 'I am happy'; [N,e]=histcounts(double(string),32:130); table(char(e(N>0)'),N(N>0)','VariableNames',{'Character','...

4 días ago | 0

| accepted

Why the outcome of my code is just white image?

Give imshow() a second argument to see the desired grayscale range. img1=im2gray(imread('cameraman.tif')); kernel = ones(3, ...

4 días ago | 1

if and sum not working together

Because the sum cannot be done exactly in floating point. Therefore you need a tolerance, a = zeros(10,1)+0.001; b = sum(a) i...

5 días ago | 1

| accepted

what exactly norm(x) function do?

Assuming you only care about p=2, If you already have code that computes norm(x) for real x, you can extend it to complex x via,...

5 días ago | 0

Formula for norm(x)

Assuming you're only interested in p=2, if you already have code that computes norm(x) for real x, you can extend it to complex ...

5 días ago | 0

Multiple Image reconstruction with real and imaginary part in 2d array

What is the name of the variable stored inside the .mat files? If I assume it is X, then, a_real = load("img_real.mat").X; a_i...

5 días ago | 0

| accepted

Equality between 2 floats not recognized when using <= relational operator

I feel pretty confident that either Money_types or Var2 is not truly equal to 0.05 in spite of what you suppose. It may appear t...

5 días ago | 0

Concatenate vectors stored in cell array

cell2mat( reshape( yourCell.' ,1,[],27) )

6 días ago | 1

Why ifft results of analytic signal spectrum don't match with theoretical time formula?

The IFFT and the continuous inverse Fourier transform are not the same thing. tau=0.4; t0=2.8; mag=10; Fs=200; dT=1/Fs; ...

6 días ago | 0

| accepted

Add constraints to intermediate variables in the process of using least squares to minimize the objective function to fit the parameters of the equation

With the constraints you mention, the problem does not fall within the scope of lsqnonlin. You will have to use fmincon, which a...

6 días ago | 0

| accepted

regionprops Bounding box property returns values outside image dimensions

You should be comparing BoundingBox(1) with ImageSize(2) image = imread('https://www.mathworks.com/matlabcentral/answers/uploa...

6 días ago | 1

How do I graph a summation over an interval?

n=(0:10).'; fcn=@(x)sum( (2/3).^n .* cos(9.^n.*(pi.*x)) ); fplot(fcn,[-1,1]/10)

6 días ago | 1

| accepted

How to Vectorize this Code?

n3Array=normalize(n3Array,2,'n'); b0=b0/norm(b0); b0angles=acosd(n3Array*b0);

6 días ago | 0

| accepted

ScatteredInterpolant for Surface Extrapolation

The surface appears to be very well modeled by a Gaussian. An appropriate thing would therefore be to extrapolate using a Gaussi...

7 días ago | 0

| accepted

ScatteredInterpolant for Surface Extrapolation

[MAP_X,MAP_Y,MAP_Z]=readvars('https://www.mathworks.com/matlabcentral/answers/uploaded_files/1131415/MATLAB.csv'); res=@(q)re...

7 días ago | 0

Using the output of one run of a function as the input of another iteration of that function

for i = 1:Counter List = ReduceArray(List); end

7 días ago | 0

How should we evaluate the similarity of two graphs?

I don't know why you think the MSE is "large", but perhaps the percent area difference would be more suitable to you: load elli...

7 días ago | 0

How to edit the name of a variable which is an object of a class?

This might be what you want. obj={GridSys1,GridSys2,GridSys3}; %list of objects [I,J]=find(A.*(1-eye(size(A)))); K=numel(...

7 días ago | 0

| accepted

Find max value in polyfit

xcrit=roots(polyder(q1)); %set derivatives to 0 xcrit(imag(xcrit)~=0)=[]; %get rid of non-real solutions zmax=max( polyva...

8 días ago | 0