Community Profile

# Steven Lord

### MathWorks

Last seen: Today Attivo dal 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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Risposto
Viewing Symbolic Matrix Entries in Variable Tab?
If you're planning to use the symbolic expression in a loop you may want to create a MATLAB function file from it using matlabFu...

circa 11 ore fa | 0

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Grey Wolf optimizer in matlab
The ability to define local functions in scripts was introduced in release R2016b.

circa 18 ore fa | 0

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App designer: How to define self-referring properties?
That code does not define a variable named x. It defines an object property named x. You're assuming that defining one property...

3 giorni fa | 1

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rng usability missing seed functionality
It looks like using "seeds" is being considered "old fashioned" in Matlab 2022b, and there is a warning about it suggesting it w...

3 giorni fa | 0

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How do I use matlab.uitest.TestCase to open my app once and perform multple function tests?
You could do this by opening your app in a TestClassSetup method and storing a handle to it in a property of your test class, bu...

4 giorni fa | 1

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How can I access the following builtin function code? [L,p] = chol(A,'lower')
We don't distribute the source code for the built-in chol function.

4 giorni fa | 0

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Trying to Increase efficiency by avoiding using If statements to select data
Can you dynamically create and access variables with numbered names like x1, x2, x3, etc. or similar names like L_Data and R_Dat...

4 giorni fa | 0

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Is Home version an annual-basis or one-time purchase?
For your first question does the MATLAB Home product page (and the FAQ at the end of that page) provide you with sufficient info...

5 giorni fa | 0

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How to Convert symbolic variables to numeric
If it contains no symbolic variable use double. two = sym(2); sqrt2 = sqrt(two) x = double(sqrt2) If it does contain a symbo...

5 giorni fa | 0

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Why in the Test Manager; option of select New > Test for C/C++ Code is not appearing?
According to the Release Notes the capability to perform C/C++ code testing in the Test Manager was introduced in release R2021a...

6 giorni fa | 0

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How to separate real and imaginary components from a given expression in Matlab?
syms X1 X2 XC RL Zin=((X1*XC)-1i*(X2*RL))/(RL+1i*(X1*X2*XC)); A=real(Zin) B=imag(Zin) What leads you to believe something ...

7 giorni fa | 1

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ODE solver not running full time span
That suggests to me that you should have received a warning but perhaps you've suppressed it? Something along the lines of "Fail...

7 giorni fa | 0

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What are the differences between integral and trapz?
The integral function accepts a function handle as input and computes the integral of that function over an interval by evaluati...

7 giorni fa | 2

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how do i solve this error: Undefined function 'imnoise' for input arguments of type 'uint8'.
The imnoise function is part of Image Processing Toolbox. Check the output of the ver function to determine if you have this too...

9 giorni fa | 0

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I am learning still and i have no idea how to write 8y''' - y' = cos(20t) + sin(2t) in matlab
How are you trying to solve the ODE? Numerically or symbolically? If numerically, see the van der Pol example on this documenta...

9 giorni fa | 0

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using linspace in a matrix incrementing by a certain number
There are several functions for creating regularly spaced vectors of given lengths depending on which three of the four paramete...

11 giorni fa | 0

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Can we get functions from the curve fitting toolbox?
You can evaluate a fit as shown by the sections on this documentation page and this documentation page whose names start with "E...

11 giorni fa | 0

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MATLAB switching between integer and floating numbers in a loop during computation
What you're missing is that 0.1 is not exactly one tenth. Welcome to the world of floating point arithmetic. See the "Avoiding C...

12 giorni fa | 0

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MATLAB 'copy command' has unrecognised function or variable
The command is correct. I just tried it and it opened the example as I expected. From the Release Notes for release R2022b, "Ma...

12 giorni fa | 0

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How can I replace inline
To convert a symbolic expression into something you can evaluate numerically use the matlabFunction function.

12 giorni fa | 0

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where is the assised function in the example of using cycle-GAN denoise?
In general, to access helper functions for an example you should open the example in MATLAB (either your desktop installation of...

12 giorni fa | 0

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Unrecognized property string for class Panel
Since handles.fitting1 is a Panel object according to the error message, let's look at the list of Panel properties and see if S...

13 giorni fa | 0

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How can i found the infelction point from the data and remove the data before the first and last infelction points.
The ischange, islocalmin, and/or islocalmax functions may be of use to you, as might the corresponding Live Editor Tasks Find Ch...

14 giorni fa | 0

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How to make a function and input another function
I think what you want is: y = bbb(@humps, 0.5, 1) function [i] = bbb (r,a,b) i=r(a)-r(b); end

14 giorni fa | 1

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Getting error : Unrecognized field name "array".
Does this command indicate that train.mat contains a variable named array? whos -file train.mat % or whos('-file', 'train.mat')...

14 giorni fa | 0

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Using strjoin to put as a variable name in a table
Specify VariableNames as either a cell array containing char vectors or as a string array. Don't specify them as a cell array co...

14 giorni fa | 1

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Why is 'step' function not accessible (MATLAB online and installed)
As far as I'm aware none of the functions named step in MATLAB can be called with no input arguments. Is this perhaps a script o...

15 giorni fa | 0

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Genvarname for array of structs with indexing
Can you dynamically create variables with numbered names like AB1, AB2, AB3, etc.? Yes. Should you do this? The general consens...

17 giorni fa | 0

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Time-based integration of ODEs
The problem you've written out looks quite similar to the "Pass Extra Parameters to ODE Function" example on the ode45 documenta...

17 giorni fa | 0

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Dot indexing is not supported for variables of this type in a for loop
First: n_snapshots = natsortfiles(files); n_snapshots was a struct array. But then: if iscell(n_snapshots) == 0; n_snaps...

18 giorni fa | 0

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