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Steven Lord


MathWorks

2,887 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
SYMS expression not being replaced with values
Do any of your expressions involve division by 0 if you substitute lambda = 0? Running your code in the Live Editor, I don't bel...

22 hours ago | 0

Answered
Check if element in array are square of each other
I would probably do this using some subset of the ismember, any, sum, all, and/or isequal functions. Read through the help text ...

1 day ago | 2

Answered
Vectors of the sums for an array of arbitrary dimensions.
I have overcomplicated a relatively simple problem, which essentially boils down to summing over all dimensions of the array wi...

2 days ago | 0

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Answered
Is there a good pattern to combine unit testing and performance testing?
Generally, a performance test class that subclasses from matlab.perftest.TestCase is also a unit test, since the performance tes...

2 days ago | 0

Answered
supporting files for matlab example
Open the example Live Script in the Live Editor. The helper functions are in the same directory as the example. When the example...

2 days ago | 0

Answered
confusion related to 'for' loop.
Do you need the elements in a cell array, or is having them in a regular vector sufficient? epsilon = 2; thepowers = 1:8; p =...

3 days ago | 1

Answered
How to normalize all the matrices in a loop so that each row sums up to 1
The sum of the absolute values of the elements of a vector is the 1-norm. You can use the normalize function introduced in relea...

3 days ago | 1

Answered
There is an error in exp function but it doesn't tell what the error is?
M(1, 1) refers to one element in M. I suspect one of a and DivW is not a scalar (I'm guessing one of them is 1-by-61, the size ...

3 days ago | 0

Answered
Problem integrating a function handle which contain an integral
What requirement does integral2 place on the integrand function you pass into it as the first input? From the documentation: "Th...

3 days ago | 0

Answered
Sparse to full matrix conversion not working...
Something is definitely odd here. Your A and AA should be full matrices, not still sparse. Let's make sure you're calling the c...

4 days ago | 0

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Answered
I am trying to make an algorithm within Matlab. I have 4 constraints that I need to hit: any suggestions are appreciated.
No, not without involving negative amounts of some of these foodstuffs. Consider if you ate just one of these entries exclusive...

4 days ago | 0

Answered
Problems to install matlab in windows 10 for user
Try the steps in this Answer. If after following those instructions MATLAB still continues to prompt you to activate every time ...

4 days ago | 1

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Answered
How to plot an alphaShape to a specific axes in app designer
The plot method of alphaShape objects does not accept an axes handle as its first input. Instead you'll need to specify the uiax...

5 days ago | 1

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Answered
Conversion function taking a very long time to run in loop, anyway to improve?
Call asind on arrays of data instead of on scalars. Use the hypot function if your data is real. n = 100; X = rand(n); Y = ra...

5 days ago | 0

Answered
Error in first line of edfread.m
Leave the first line of the function in the declaration as the following: function [hdr, record] = edfread(fname, varargin) Wh...

8 days ago | 1

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Answered
how to plot fewer marker ?
The MarkerIndices property was introduced in release R2016b. If you're using an older release, consider upgrading to R2016b or a...

8 days ago | 0

Answered
Create cell array from 00.00 to 23.59
minutesAfterMidnight = minutes(0):minutes(1):(hours(24)-minutes(1)); minutesAfterMidnight.Format = 'hh:mm'; firstTen = minutes...

8 days ago | 0

Answered
How can I bin Data
If I understand your application correctly use histcounts2 to bin the data. The fourth and fifth output are the indices of the b...

9 days ago | 0

Answered
How to create class from .txt
While you can create individual variables from the rows or columns of a matrix, doing so is strongly discouraged. If your matrix...

9 days ago | 0

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Answered
Custom function App Designer [Matlab] [App Designer]
No, the app object is not optional. You must pass it into the method in order to invoke the method. What you're seeing is one o...

9 days ago | 1

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Answered
Report Generator Program Example https://uk.mathworks.com/help/rptgen/ug/create-a-report-program.html
That documentation page is for the most recent release of MATLAB Report Generator, currently release R2018b. The Release that yo...

9 days ago | 0

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Answered
integers error in matlab
n= (( 4.6 / 2 ) / 0.1 ) + 1 In theory, n is an integer value, specifically 24. In practice, because neither 4.6 nor 0.1 are ex...

10 days ago | 0

Answered
I need to know how to organize a find statement into a set order with characters instead of it's number's. I want information to come out like below.
discretize your data. A=[18 33 31 34 15 37 10.5 48 50 38 35 39 42 33 ... 31 1 5 9 13 11 27 35 -1 46 22 6 19 36]; volt=rou...

10 days ago | 1

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Answered
Online access to MATLAB
According to the MATLAB Online product page, if you are current with a MATLAB and Simulink Student Suite license or a MATLAB Stu...

11 days ago | 0

Answered
I do not know what's wrong with my code
If you receive an error when running your code, post the full text (everything displayed in red) of the error message you receiv...

11 days ago | 0

Answered
Not enough input arguments
Your function is declared to accept six input arguments: function E = ecc_anomaly(tow, toe, GM, sqrta, M0, ecc) When you call ...

12 days ago | 1

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Answered
Class method calls method of other instantiated class
If the object stored in the offer property of the Operator class is a CentralMarket object, this should work. function submitOf...

12 days ago | 0

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Answered
How to generate a file name by combining variable characters based on the input of the matlab?
If you're using a sufficiently recent release of MATLAB, you can combine string, char, and numeric data using +. name='abc'; a...

12 days ago | 0

Answered
audioDatastore Variable or Function undefined
The note at the end of the documentation page for the audioDatastore function states "Introduced in R2018b". If you are using an...

13 days ago | 1

Answered
Peak "coordinates of a histogram
Are you creating the histogram (the graphics object) or binning the data using histcounts? In the former case. retrieve the Bin...

13 days ago | 1

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