Community Profile

Steven Lord


MathWorks

2,211 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 the MATLAB Newsgroup 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
Re-sizing vectors?
When you call the |plot| function with one input argument, the X coordinates used for the plot are the indices. In this example,...

24 hours ago | 0

Answered
Transferring a symbolic expression to a odefun
If you want to solve the ODEs numerically, read through the examples for the <https://www.mathworks.com/help/symbolic/odefunctio...

2 days ago | 0

Answered
Error in ode45 using odearguments: "Inputs must be floats, namely single or double"
The function you pass into |ode45| *must* return a |single| or |double| precision array, not a symbolic array. It may internally...

3 days ago | 0

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Answered
I need to leave values in an array in blank. NaN problem
If you use |NaN| or |missing| (which for numeric arrays are the same thing) to represent the missing data in your data set, you ...

3 days ago | 0

Answered
Why function 'sparse' is not supported by Matlab compiler?
According to the <https://www.mathworks.com/help/coder/release-notes.html?rntext=sparse&startrelease=R2015a&endrelease=R2018a&gr...

3 days ago | 0

Answered
Error in importing data in community detection toolbox
You'll probably have better luck if you try contacting the author of that File Exchange submission directly.

3 days ago | 0

Answered
How can people who are bad at math and have no programming aptitude learn MATLAB? (Long question)
Perhaps working through some of the <https://www.mathworks.com/support/learn-with-matlab-tutorials.html introductory tutorials> ...

4 days ago | 2

Answered
Number of elements must be the same?
Are you certain that at each iteration of your |for| loop at least one element in |abs(V(:,j)-K+S)| is strictly less than eps_st...

4 days ago | 0

Answered
How do I make a script which can call for other scripts for every x time interval?
You probably want to use a |timer| object.

4 days ago | 0

Answered
Daily Returns to Biweekly Returns
If you're storing your data in a |timetable| array, use the |retime| function.

5 days ago | 0

| accepted

Answered
Renaming columns within the variable editior screen
So you want to create either 136 or 4*136 = 544 individual variables (depending on whether you "combined" them vertically or hor...

5 days ago | 0

Answered
Why is det a bad way to check matrix singularity?
A non-zero scalar multiple of the identity matrix is about as far from singular as you can get, right? A = 0.1*eye(400); ...

9 days ago | 3

Answered
outedges function is not defined in my Matlab2017!
According to the note at the end of its documentation page, the <https://www.mathworks.com/help/matlab/ref/graph.outedges.html |...

9 days ago | 1

| accepted

Answered
Does uigetfile in MATLAB 2018 no longer support *img-files?
You're trying to turn the variable mask which according to the help text in getbeta_chf is "a file name (full path if not in the...

9 days ago | 1

Answered
Determine outlne of dataset points
As Walter suggested, |boundary| is one option. Depending how tightly you want the boundary to surround the points, <https://www....

9 days ago | 0

Answered
Spectral radius of matrix?
Ask the |eigs| function to return the largest magnitude eigenvalue. % Generate a vector of eigenvalues suitable for the 'ra...

9 days ago | 1

Answered
Using a second call to copyobj is not working
If you want an axes with rulers on both the left and right, you should use |yyaxis|. If you're using a release that predates the...

9 days ago | 0

Answered
Replace NaN with mean of previous values
Use the <https://www.mathworks.com/help/matlab/ref/fillmissing.html |fillmissing| function>, specifically the |F = fillmissing(A...

10 days ago | 1

Answered
Computing a weighted sum of matrices
If you're using a release that supports <https://www.mathworks.com/help/matlab/release-notes.html?rntext=%22implicit+expansion%2...

10 days ago | 0

Answered
using fminsearch--how to realize the display of the x values in every step of iteration?Thank you!!!
See the examples in <https://www.mathworks.com/help/matlab/math/output-functions.html this page in the documentation>. You ca...

11 days ago | 1

Answered
ODE45 & heaviside- [Inputs must be floats, namely single or double.]
The |ode45| function cannot accept functions that return a |sym| object as the first input to |ode45|. You could use symbolic ca...

11 days ago | 0

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Answered
Error in symbolic engine with latest R2018a Trial
Are you using Windows 10 Spring Creator Update 2018? If so see <https://www.mathworks.com/support/bugreports/1755918?s_tid=answe...

11 days ago | 0

Answered
Define matlab functions with input selected from a "list"
If I understand your description correctly, it sounds like you want to implement tab completion for your function. If you're usi...

11 days ago | 0

Answered
B = A(abs(diff(A))); i want to find the abs difference of 08 values
You've likely created variables named abs and/or diff. Rename those variables and you will be able to use the |abs| and |diff| f...

11 days ago | 0

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Answered
query regarding while loop application
I think what you want is the <https://www.mathworks.com/help/matlab/ref/discretize.html |discretize| function>, though the fact ...

11 days ago | 0

Answered
I have the symbolic math toolbox, but 'syms' isn't working. How can I fix this?
Are you using Windows 10 Spring Creator Update 2018? If so see <https://www.mathworks.com/support/bugreports/1755918 Bug Report ...

12 days ago | 0

| accepted

Answered
Handle invalid fieldnames when parsing python dict to matlab via struct
If you can get a list of the names in your dict object that you want to be the fieldnames in the MATLAB |struct| array, pass the...

12 days ago | 0

Answered
Calculating the probability of a data point in a histogram
Change the Normalization property of the |histogram| object then get the appropriate element of the Values property of that obje...

12 days ago | 0

| accepted

Answered
Not able to access functions in Matlab 2018a
Those functions are helpers for the example and are mainly intended to be used by the example, not reused for general purposes. ...

12 days ago | 0

Answered
Populating a Legend Dynamically
Rather than building a large cell array of names that you pass into |legend|, I would instead use the DisplayName property of th...

12 days ago | 0

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