Steven Lord

Last seen: Today

MathWorks

4,651 total contributions since 2002

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

For assistance with MATLAB question please post to MATLAB Answers or contact Technical Support using the Contact Us link in the upper-right corner of the page instead of contacting me directly.

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Answered
Compare two text files from MATLAB Command Window using FC Windows 10 file comparison command
Use the system function instead of the ! (bang) operator.

3 hours ago | 2

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Answered
Extracting specific rows with different content from a large table array
Consider storing your data in a timetable, converting your MatDate variable into a datetime array and using table2timetable (or ...

4 hours ago | 1

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Matrix cos. Did I write the expression and correctly?
You can check your answer using the funm function in MATLAB.

4 hours ago | 0

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I did Exercise 3.1 by commenting the code. However while doing Exercise 3.2 onwards part (a) I am getting some errors. I had pasted my code below the pictures.
Your assignment instructs you to write a MATLAB function image_sample but you have written a MATLAB script image_sample. See thi...

5 hours ago | 0

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How do I fix this ?
In addition to the output argument renaming others have suggested, as written you need to assign something to the output argumen...

8 hours ago | 0

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How to install DSP system Toolbox in an Offline Machine?
See this Answers post.

8 hours ago | 0

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Why is matlab busy?
i = 1+1; Did you mean to add 1 to i rather than adding 1 to 1? The length of r is greater than 2, so the condition of your ...

15 hours ago | 0

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About function in methods of a class
If getRandomMusic is a non-Static method of a class (which I'll call iPod just to have some way to refer to the class) then at l...

15 hours ago | 0

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Citing MathWorks Documenation (ASCE format)
This Answers post offers some suggestions.

18 hours ago | 0

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simple problem with double integral, why give me an error?
The function you pass into simulannealbnd must return a double array not a sym array. Convert the value of the integral into dou...

19 hours ago | 0

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SOS: How do I get the same amount of positive and negative values in a random vector?
% Generate sample data x = randn(1, 50); y = randn(1, 50); % Determine where positive and negative values occur in each xp...

1 day ago | 0

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Answered
How to...live script
When you're checking with your calculator, are you taking the sine of x in degrees (for which the corresponding function in MATL...

2 days ago | 0

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How to Display a message in a separate window
If you're using App Designer use uialert. If you're not using App Designer use msgbox.

2 days ago | 0

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Undefined function 'mtimes' for input arguments of type 'function_handle'.
You can't multiply a function handle and a number or two function handles. You can multiply the result you get from evaluating ...

3 days ago | 0

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Answered
Solve (a*B) + (c*D) = E without the Symbolic Toolbox
This is a generalization of Cleve's simplest impossible problem. Cleve's has B = 1/2, D = 1/2, E = 3.

3 days ago | 0

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Add Edges to Network Graph Without Changing the Layout
plot the first graph. Turn hold on. plot the second graph, specifying the XData, YData, and (if plotting the graph in 3D) ZDat...

3 days ago | 1

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Answered
assign categorical value for weekday variables
Since you have a timetable you can use the isweekend function to get true and false values (which you could convert to categoric...

3 days ago | 0

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Answered
It shows "Your MATLAB license will expire in 5 days. Please contact your system administrator or MathWorks to renew this license."What to do
As the message suggests, I would contact your system administrator. If you're using your educational institution's license or yo...

3 days ago | 0

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Redistribution of histogram type data in specified bins
>> x = randi(12, 1, 1000); >> h = histogram(x, 0:4:12); % Look at the histogram before running the next line of code >> h.B...

3 days ago | 0

Answered
How to make a list of appearance
histcounts and histogram can handle categorical arrays. names = ["cat" "dog" "cat" "cat" "dog"]; animals = categorical(names);...

3 days ago | 0

Answered
Something is wrong with my Matlab
A = [x x x; x y y; y -2z] b = [60 30 3]' I suspect this is supposed to represent the equations 3*x = 60, x+2*y = 30, y-2*z = 3...

4 days ago | 3

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Answered
Convert/copy array to different type of array (single to uint16 for example) bit by bit
Are you trying to typecast one of the variables into the other?

4 days ago | 0

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Answered
Variable from function to change value
What's the purpose of your function? Is it simply to score the set of dice (meaning that it's some other function, perhaps its c...

4 days ago | 0

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Help calling my basic function
That is the correct and documented behavior. See the first Note on this documentation page. You could do this by either creatin...

4 days ago | 1

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Python 3.8 interoperability
The Release Notes for release R2020b indicate that cPython 3.8 is now supported.

5 days ago | 1

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Row unity in matrix
>> P = rand(9); >> NP = normalize(P, 2, 'norm', 1); >> sum(NP, 2) ans = 1 ...

5 days ago | 0

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Index daily values in TT over many years to determine mean
Use groupsummary with the GROUPBINS input specified as "dayofyear".

5 days ago | 1

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Can someone provide me the theory and math behind this function of eigen?
You might find the "Eigenvalues and Singular Values" chapter in Cleve Moler's Numerical Computing with MATLAB, available here, u...

5 days ago | 0

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Can't figure out the error in my pcolor line, keep getting color data input must be a matrix error
Please run this command immediately before the line where you call pcolor and show us the output from just before the pcolor cal...

6 days ago | 0

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Answered
Error using barrier Objective function is undefined at initial point. Fmincon cannot continue.
What values do you receive when you evaluate your objective function fun at the initial values in the start field of the paramet...

6 days ago | 0