Community Profile # Steven Lord

### MathWorks

Last seen: Today Active 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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How do I pick a number from a set of random numbers?
Since I suspect this is part of a homework assignment I'm not going to give you the answer, but I will point you toward two func...

alrededor de 4 horas ago | 0

Efficient way to solve an equation in MATLAB
Solve numerically using fzero. Here I've written a function handle that itself makes function handles. I can pass that generated...

alrededor de 10 horas ago | 1

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How to find parent uifigure for a child several layers down
Use ancestor. >> f = uifigure; >> h = uipanel('parent', f); >> f2 = ancestor(h, 'matlab.ui.Figure'); >> f == f2 ans = ...

2 días ago | 1

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if and sum not working together
Please try this little experiment. Find something to write with and something to write on (ideally compatible things; pencil and...

2 días ago | 1

Would like a script that removes repeat data
Dates_Wrong = ['2/4/21';'2/5/21';'2/5/21';'2/6/21';'2/7/21'] dt = datetime(Dates_Wrong, 'InputFormat', 'M/d/yy') differences =...

2 días ago | 0

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Equality between 2 floats not recognized when using <= relational operator
I searched it up and apparenty it's to do with matlab not storing floats very accurately, No, that is not the cause. Are the n...

3 días ago | 1

divide year time data into days and nights
I'm going to use the sunrise and sunset times for Natick, MA for this example. I'll create some random datetime values for the n...

4 días ago | 2

APP Designer code convert to CPP code
If upgrading to a release (R2020a or later) that includes Simulink Compiler is an option, you might find the workflow on this do...

4 días ago | 0

How to obtain the piecewise expressions of spline fit obtained using MATLAB's command spapi?
i want to obtain the expression and calculate it derivatives further. Do you need the actual expression, or do you just want to...

4 días ago | 1

Add code to have switch repeat if a case is not met
You can simplify your switch call so you don't have to include 2^(number of letters) cases each with a different combination of ...

4 días ago | 0

How can I drawing equipotential lines?
Take a look at the contour function.

5 días ago | 0

installing two MATLAB versions at same time.
It is possible to have multiple versions of MATLAB installed on the same machine at the same time. Just don't install them both ...

5 días ago | 0

I need to understand what's the mistake and how to define vector
When MATLAB runs line 7 of your code, it tries to access the second element of the variable u (or to call a function named u wit...

5 días ago | 1

How to reduce the file size of a saved histogram figure
You could avoid creating the histogram using the data by specifying 'BinCounts' and 'BinEdges'. If you do this, there won't be a...

5 días ago | 1

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Is it possible to generate a Mex function which has within it another mex function?
I'm not 100% certain but if you're trying to generate code using MATLAB Coder on a file that calls a MEX-file, you may be able t...

5 días ago | 0

Join strings together with '_' between them
Use the string append operator +. a = {'A11';'A12';'A21';'A22';'A23';'A24'}; b = {'A300';'A5300';'A291';'A5291'}; C1 = a + "_...

5 días ago | 1

Identifying if reaction times are 3 standard deviations away from mean
Take a look at the "mean" method for the isoutlier function.

6 días ago | 0

Translate sine coding? Need understanding
To start off, I suggest you start with the free MATLAB Onramp tutorial to quickly learn the essentials of MATLAB. Then work you...

6 días ago | 1

How to fix the large and mad fractions when dealing with symbolic vars
Symbolically, use vpa or double or use the sympref function to change the FloatingPointOutput preference. Numerically, if you w...

7 días ago | 1

Why is my table displaying 1x1 in workspace but displays actual values in command window?
You're creating a timetable whose elements are tables. If you want to change a table into a timetable instead take a look at the...

7 días ago | 0

How to subtract ?
A=[0 1 2 3 4 5 6]; B = 12; C = B-cumsum(A)

10 días ago | 2

error when I try to open a file to edit
Do you have a function you've created named settings.m? Does the command below show just one item (in a subdirectory under toolb...

16 días ago | 0

how can i change the value of a variable with a slider in matlab designer?
Rather than changing the value of a fixed variable I would likely retrieve the Value property of the slider object whenever I ne...

16 días ago | 0

MPC toolbox computation time
If you're trying to analyze the performance of your Simulink model (to identify bottlenecks?) consider using Simulink Profiler.

16 días ago | 0

I wan to display an image of size 512x512x150 using matlab.
Take a look at the tools listed in the Volume Visualization section of the documentation.

16 días ago | 0

why my conditional function is not what I expected?
if X>=0 & X^2+Y^2<4 From the documentation for the if keyword: "if expression, statements, end evaluates an expression, and exe...

18 días ago | 1

Why isn't my figure consistent? It keeps changing every time
Here's one line of your code. I've put it in block comments so MATLAB Answers won't try to execute it, since I have other code l...

18 días ago | 0