Community Profile # Steven Lord

### MathWorks

Last seen: Today 自 2002 起处于活动状态

I joined The MathWorks in the Technical Support department during the summer of 2001 and transferred into the Quality Engineering department in March of 2004. I now work qualifying the core MATLAB numerical functions (PLUS, MINUS, LU, FFT, ODE45, etc.)
Professional Interests: mathematics, MATLAB

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Assigning equation output to second row of a matrix
Implicit expansion. velocity = (1:3).'; % column vector thrust = 10:14; % row vector A = velocity./thrust % Dividing results ...

9 hours 前 | 0

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ode45 graph issue
Instead of defining your integrand function piecewise like this: % Define the thrust as a function of time T = @(t) 6500*(t<=1...

9 hours 前 | 0

I want to extend my license.

10 hours 前 | 0

Does Matlab provide any tools to understand the contents in an image and describe it using words?
There are examples in various products (mainly using Deep Learning Toolbox and/or Computer Vision Toolbox) to perform image clas...

10 hours 前 | 0

Getting values separated by commas from a string array
You can do this with split and double. S = ["52,884,410" "44,878,410" "46,896,410" "82,941,410"] S2 = split(S, ",") D = do...

1 day 前 | 1

Philosophical question: How to get a vector from the output of solve? Why isn't it a vector already?
syms x y sol = solve(x == 5, y^2 == 4) sol.x sol.y How exactly would you want those two solutions to the system of equations...

1 day 前 | 0

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Rather than having your CheckforErrors function return true or false as the first output argument I'd have it throw an error usi...

1 day 前 | 0

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Please send this licensing question to Technical Support directly using the Contact Support link under the Get Support heading a...

1 day 前 | 0

How can I obtain all possible combinations of given vectors in MATLAB?
As of release R2023a you can use the combinations function in MATLAB for this task. T = combinations(1:3, 4:6) While combinati...

5 days 前 | 1

streamline line value v=atan(y/x) not giving me "Warning: Matrix is singular to working precision"
I'd recommend using atan2 instead of dividing. If you had to divide, use element-wise division (the ./ operator) instead of matr...

5 days 前 | 1

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No out of memory error but matlab crash
Did MATLAB crash or did the operating system kill it? Check if there's a message in the log file that the Out of Memory (OOM) ki...

5 days 前 | 1

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How to Draw a Pentagon or Polygon by Using Function
Why not just use nsidedpoly? P = nsidedpoly(5); plot(P); axis equal

6 days 前 | 1

I am getting parse error for this following simple program
Please show us the full and exact text of the warning and/or error messages you receive (all the text displayed in orange and/or...

6 days 前 | 0

Toolbox have added. And the m-file of the function can be found buy 'Which'. However, ERROR: function need the Toolbox
In order to run a function from a toolbox two conditions must be true. I'm going to write in the context of a desktop installati...

6 days 前 | 0

How do you include a mass matrix in ode45?
The "Summary of ODE Examples and Files" section on this documentation page lists a number of examples and indicates which of the...

7 days 前 | 0

how ode solver works
I am looking for knowing or displaying time step in ode solver. At what point during the solution process? If you're trying to ...

7 days 前 | 0

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Problems accepting integer values with power and algebraic symbols using inputdlg
The str2double function is a bit particular about the formats of text that it will convert to double. The format you've describe...

8 days 前 | 2

Not valid variable name despite variable declaration i MATLAB app designer.
'app.para_BF_new' is not a valid variable name. The error message is correct. 'app.para_BF_new' is not a valid variable name. I...

9 days 前 | 0

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How to find the original vector given the outer product of the vector?
n = 3; psi1 = rand(n,1) + 1i * rand(n,1) outer_product1 = psi1 * psi1' psi2 = 1i*psi1 outer_product2 = psi2 * psi2' norm(ou...

9 days 前 | 0

How to get the workspace of a debugged function, from within a GUI debugger
Why not just use the debugging tools included in MATLAB?

9 days 前 | 0

Undefined function or variable 'sigma_sj'. Error in m_phi_code (line 110) Ps_j = sigma_sj*(N/2)*(3.14/4)*d^2*0.001; why this error is showing?
What value should sigma_sj have if none of the conditions in your large if / elseif / elseif / ... statement are satisfied by th...

10 days 前 | 1

Listmonth and listyear functions
I find no entry for a function named listyear in the Help Center. There is one item in the search results for listmonth but it i...

11 days 前 | 0

Why does str2num take much longer to convert 1001 long char array apposed to a 1000 long char array (MatLab R2010b 64bit, on Win 64bit)
What's your ultimate goal here, of which I suspect this conversion is one step in a larger process? If you want to generate 100...

11 days 前 | 0

Using a matrix as an index of another matrix
Take some shuffled data. r = randperm(10) Now sort it. [sortedData, indices] = sort(r) We can get back to r from sortedData ...

11 days 前 | 0

class 'matlab.io.datastore.PixelLabelDatastore' is not allowed. Error !!!!!
You can make an array of numeric data in MATLAB. A = [1 2; 3 4] You cannot make an array of PixelLabelDatastore objects like t...

11 days 前 | 0

Taking away transfer functions
by hand this should give me (5s-90)/s but MATLAB is giving me (5s^2-90s)/s^2 Assuming s isn't 0 (in which case evaluating your ...

12 days 前 | 0

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New Workplace variable from Table
Is there a way to code a script to do this without manually picking the columns? Or a way to create new workplace variables from...

12 days 前 | 1

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Datastore problems with deep learning. "FileExtensions Name-Value"
The imageDatastore object's documentation page states, in the description of the location input argument, that it "supports file...

12 days 前 | 0

App designer and runtime compiler problem for creating exe file
I created an app with app designer and with Matlab 2021a version. I also download Matlab Runtime (version 2021a). If you down...

12 days 前 | 1

How do I receive modelling help/support for my Master Thesis Project?
If you have questions that reasonably fall under the responsibility of Technical Support (more "Why do I receive error X when I ...

12 days 前 | 2