Steven Lord

Last seen: Today

MathWorks

4,627 2002 年以降の合計貢献数

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.

Steven Lord's バッジ

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

約5時間前 | 1

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

約7時間前 | 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".

約11時間前 | 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...

約20時間前 | 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...

1日前 | 0

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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...

1日前 | 0

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How to modify an anonymous function with another function
As written, y1sig and y2sig aren't function handles. You could make them function handles like this: f1 = @(d) sind(d); f2 = @...

3日前 | 0

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How I can correct this error? "Undefined operator '/' for input arguments of type 'function_handle'."
z=@(x) x(1)+x(2)+x(3)+x(4)+x(5); F1=@(x) 19720+(R*T*log(x(1)/z))-x(6)-4*x(7); You can't divide x(1) by the function handle z. ...

3日前 | 2

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specifying the horizontal linetype '_' produces an error.
The horizontal and vertical line markers for plots were introduced in release R2020b. If you're using an older release you will ...

3日前 | 2

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Property access in subclass
As you've defined A and B they are value classes but you're using them like they are handle classes. See this documentation page...

3日前 | 0

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Error using odearguments with a symbolic system of differential equations
Your ODE function can use symbolic calculations internally but it must return a double or single array to the ODE solver. Call d...

3日前 | 0

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I can't find the mistake in the code
I've seen two different conventions for representing polynomials as vectors of coefficients. The one used by functions like poly...

4日前 | 0

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How to extract input variable name when calling to GUI (GUIDE) function?
If you want your app to display the name of the file that was loaded, you should probably have your app accept the filename rath...

4日前 | 1

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System Error (MATLAB R2019a) after update
See Maadhav Akula's answer on this Answers post.

4日前 | 1

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Why do I get these errors in Toolbox package? Help me out
The MCR directories in the directory for MATLAB Compiler should not be on the MATLAB path. If you've added toolbox\compiler\mcr ...

5日前 | 0

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Error using 'pi' too many input errors with my equation
You're missing * operators after the two calls to pi on the line where you define y, just like you did on the lines where you de...

6日前 | 0

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Even binned histogram to uneven bins?
Let's make some sample data. x = randi(255, 1, 1e5); Use bin edges that are the squares of the integers between 1 and 16. Each...

6日前 | 0

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Error using subplot using for loops: subplot index too large
Set a conditional breakpoint on the line where you call subplot. The condition is nVals1*4 < indexplot. Run your code. When MATL...

6日前 | 0

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Array of Structures (not structure array)
Consider a struct whose fields are themselves struct arrays. arr.asdf = struct('A', 3, 'B', 2); arr.zxcv = struct('A', 7, 'B',...

6日前 | 1

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Unable to use CTRL+R to comment
Open the Preferences using the button in the Enviroment section on the Home tab of the Toolstrip. In the MATLAB section of the p...

7日前 | 0

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How to upgrade Matlab Online?
I'm not on the MATLAB Online team but I see in the Application Status page that there was an issue around noon that caused some ...

7日前 | 0

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Setting Limits to end of table Variable
Use bounds and/or min and max on your time data to find the tight bounds and use those with xlim to adjust the limits.

7日前 | 0

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Simplifying a matematical expression
After inserting it into Answers using the sigma button on the toolstrip: Honestly, I wouldn't enter this as one term. As you ...

7日前 | 1

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How can i vectorize a matrix multiplication of higher dimension arrays?
If you're using release R2020b or later, take a look at the pagemtimes function introduced in that release.

7日前 | 1

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How to multiply N matrices without a FOR loop? (Slices of 3D array)
If you're using release R2020b or later, take a look at the pagemtimes function introduced in that release.

7日前 | 0

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Matching string from multiple arrays
If you have your data stored in timetable arrays, call synchronize with your three timetable arrays as input and specify the new...

7日前 | 0

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Table manipulation for saving variables
Here's a small example you could use as a model: T = array2table(magic(3)) % T is a 3-by-3 T(4, :) = {10, 11, 12} % T is now a...

7日前 | 0

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How to enter a function into MATLAB
Is your calculator computing the cosine of angles in degrees (which in MATLAB is the cosd function) or in radians (cos)?

7日前 | 0

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Operations Research formulation in MATLAB
Looking at the code you posted as a comment I have a couple of observations and suggestions. The Queen's MATLAB was only an Apr...

7日前 | 0

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How can I multiply N dimensional matrices
See the pagemtimes function introduced in release R2020b.

7日前 | 0