Community Profile

# Matt J

6.203 total contributions since 2009

Professional Interests: medical image processing, optimization algorithms

View details...

Contributions in
View by

How calculate the second and third numerical derivative of one variable f(x)
Matlab's diff command will do this directly, https://www.mathworks.com/help/matlab/ref/diff.html

3 días ago | 0

Creating an optimization constraint - how to only schedule one employee per time slot
The problem-based optimization workflow is especially handy for matrix-valued optimization variables. It lets you write constrai...

3 días ago | 1

Using a for loop, how can I multiply diagonal elements of a matrix NxN?
product = product*B(column,column) ;

3 días ago | 0

| accepted

Single precision matrix multiplication
The Matlab interpreter runs a special dedicated "ctranspose-multiply" function to evaluate expressions of the form, P'*Q It do...

4 días ago | 1

| accepted

Non linear fitting with constraints
You would have to use fmincon, which will let you specify non-linear constraints.

4 días ago | 0

| accepted

imwrite does not save file in specified folder :(
Try this, dest=fullfile(newpath, ['new_' file(k).name(1:end-4) '.jpeg']); imwrite(I,dest);

4 días ago | 0

| accepted

Using lsqcurvefit in a Matlab App
Here is a snippet of the code I am working with. No, the code should look like this, methods (Access = private) %...

5 días ago | 0

| accepted

Fit sum parameters of an overdetermined system
Your xdata should be a 9x11 matrix, your ydata should be a 1x11 vector, and the code for your function should look like this, f...

5 días ago | 0

| accepted

Not (~) operation of binary image after subtracting double data type of binary images. Could I have the explaination of this?
If im1 and im2 start off as uint8, then subtraction operations 0-1 will yield zero values, >> uint8(0)-uint8(1) ans = u...

5 días ago | 1

| accepted

How to separate a variable out of trigonomic expression
These identities may help,

5 días ago | 1

Unable to perform assignment because the left and right sides have a different number of elements error
It's because in that line, b is not a scalar, even though everything else is:

5 días ago | 0

Does anyone know the process of solving this problem?: "Write a MATLAB command to plot 5 cycles of s=sin(1000t)."
This very similar example may be of some help, https://www.mathworks.com/help/matlab/ref/plot.html#btzitot-4

6 días ago | 1

| accepted

least square circle, why doesn't it work?
As I mentioned in your other post, your approach is not a good way to fit a circle. However, assuming you must do it this way, y...

6 días ago | 1

| accepted

Non linear least square fitting
Ok. Could you possibly show me the analytical alternatives to Adam's solution? See attached. Note that my method does not mini...

7 días ago | 2

How can I use graph object info to find: areas, number of sides, and perimeter lengths of a each connected polygon within a network of polygons?
Using one of my recent FEX postings, https://www.mathworks.com/matlabcentral/fileexchange/73630-spatialgraph2d you should be a...

7 días ago | 0

| accepted

Submitted

spatialgraph2D
Creates a graph object with 2D spatial locations associated with the nodes

return the numerator and denimentor
If x is a symbolic variable, then yes >> x=sym(1/2); >> [n,d]=numden(x) n = 1 d = 2

7 días ago | 0

vectorize high dimensional image
result = reshape(yourImage,[],102).';

7 días ago | 0

| accepted

Using functions relating polynomial
result = conv(P,Q)

7 días ago | 1

| accepted

How to replace elements of a matrix with the scaled identity?
B=kron(A,eye(n))

7 días ago | 1

| accepted

Convert matrix 3d into 2d

7 días ago | 1

Find an optimal solution for a system with matrix
f=-A(:); Aineq=[B(:),C(:)].'; bineq=[4;3] Xoptimal=linprog(f,Aineq,bineq)

8 días ago | 0

Trying to plot Eulers, but keep getting straight line
You're getting a straight line because the right hand side of this line acmi(1:10001)=-a+(alpha(n)*l*cos(theta(n)))-((omega(n)^...

9 días ago | 0

how to write a function for quadratic equation
[x1,x2] = QuadraticEquation (1,-2,0) function [x1,x2] = QuadraticEquation (a,b,c) d=b^2-4*a*c; if d>=0 disp ('...

9 días ago | 0

| accepted

How to sum a series of numbers?
sum(numerator./denominator)

9 días ago | 0

multi-variable optimization in matlab?
Many other variables are to be calculated first, which are actually functions of the first two variables, and then they're used ...

9 días ago | 0

| accepted

Call a function in a sub directory?
The only way, I believe, is to visit each folder and create a function handle to each respective version of sayhi(), cd folder1...

9 días ago | 0

Map a 2D matrix into 3D using loop for allotment along the 3rd dimension
You could try this. clear data_trialwise for i=20:-1:1 data_trialwise(:,:,i)=data(:,begin(i):end(i)); % begin and end bot...

10 días ago | 0