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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Answered
New install 2021a not plotting data
Let's make sure you haven't accidentally written or downloaded a function that is taking precedence over the built-in functions ...

36 minutes ago | 0

Answered
Is it possible to add fine-grained operator export operations to the "exportONNXNetwork" function in a future release?
Generally we don't comment on whether something requested is planned or being implemented for a future release. [In this case, I...

1 hour ago | 0

Answered
Discrepancy between eigenvalues and eigenvectors derived from analytical solution and matlab code.
syms eb ep t V phi H=[ep+V/2 t*phi; t*conj(phi) eb+V/2] [E,v]=eig(H) Let's check if the elements in E and v satisfy the defin...

1 hour ago | 0

Answered
Sort a table by two conditions when one column is not unique
Do you need to sort the table or do you need the maximum value of F_H_max for each value of POSITION? Those are two different th...

22 hours ago | 0

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Fill a matrix with matrix powers
A = magic(3); AM = {A^0, A^1, A^2}; celldisp(AM) B = blkdiag(AM{:}) You could create AM automatically rather than hard-codin...

24 hours ago | 0

Answered
unshow unnecessary intervalls in a histogramm
x = randn(1, 1e5); h = histogram(x); C = h.BinCounts; E = h.BinEdges; C([30:40 50 60]) = 0; figure histogram('BinCounts', ...

24 hours ago | 0

Answered
To know the units of t span used in ode45 command
There is no unit inherent to the t variable used by ode45. Just implement your ODE function correctly for your time units. If y...

1 day ago | 2

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How do I find the number of hours?
I have a matrix A with dimensions 35000X1 (datetime). There are hours in matrix A. For example, 01:00, 05:00, 17:00, 23:00, 05:...

2 days ago | 0

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Answered
Clarification about modifying properties in handle class
In the preceding code, count is empty. That is correct, the default value for that propery is the 0-by-0 empty double array []...

3 days ago | 0

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Answered
Hi anyone would help mewith this error 'R_tilde = builtin('subsref',L_tilde,Idx)'
A couple comments / suggestions: syms f(t) cos sin M m1 m2 xddot xddotsq l1 l2 L1 l2 alpha alphadot alphaddot alphadot beta bet...

3 days ago | 0

Answered
Coding an if statement within MATLAB function
Define y on all the execution paths. Consider this example: q = myfun(5) function out = myfun(x) if x < 1 out = 2; else...

3 days ago | 0

Answered
How to add a specific path to Matlab in -batch mode?
For your first question, if you know you're always going to want this directory on the MATLAB path when you start your batch job...

3 days ago | 0

Answered
The third elseif does not work. I cannot figure out what's wrong with my code.
slots_a1 = zeros(10,10); slots_a2 = zeros(10,10); slots_a3 = zeros(10,10); slots_a4 = zeros(10,10); slots_a5 = zeros(10,10);...

3 days ago | 0

Answered
i want more numbers details on y axis
x = 1:7; y = x./7; plot(x, y, 'o-'); yticks(y) title('Formatted using the default format') You can use the TickLabelFormat ...

4 days ago | 0

Answered
How to speed up the computing time?
Consider turning your table into a timetable and calling retime on the timetable.

4 days ago | 1

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Answered
Matlab code on Modification of an inbuilt function
We do not distribute the source code of the inv function. Therefore if you want to modify it you will need to start on our Caree...

4 days ago | 0

Answered
how to store each for loop iteration output in a row of a matrix and then eventually get the full matrix for all iterations?
Try adapting this example that creates the 5-by-5 multiplication table to your needs. I've left off the semicolon inside the loo...

4 days ago | 0

Answered
How do I install Statistics and Machine Learning Toolbox into an existing installation of MATLAB?
I recommend contacting your license administrator (probably someone in your school or company's IT department) and asking them f...

4 days ago | 0

Answered
Explain code to me well found in the program I am new here
See the documentation for anonymous functions, the colon operator, and the fzero function. doc colon doc fzero

4 days ago | 0

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Parse error at 'class' 'properties' 'methods' and 'end', "usage might be invalid syntax"
The name of the attribute is Dependent not Dependant.

5 days ago | 0

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Convolution of function handles
Use the 'ArrayValued', true name-value pair argument as shown in the "Vector-Valued Function" example on the documentation page ...

7 days ago | 0

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Answered
Is it possible to create an Optimized Matlab RunTime to package with my app?
To contact MathWorks Technical Support create a service request using this page.

7 days ago | 0

Answered
Display result with two decimal places
format bank A=1.502357714661695e+04 B=1.096611470555982e+04 C=5.516017989036879e+03

7 days ago | 1

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Answered
how to solve four sets of ode having four variables
Use the "Example: Nonstiff van der Pol Equation" example on this documentation page to rewrite each of your higher order ODEs in...

7 days ago | 0

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Answered
Unittest: Verify whether the function prints correct error message
You can do this in one of two ways. When your function calls error have it call error with an error identifier and use verifyEr...

8 days ago | 0

Answered
How to implement class based unit tests for functions that return random results
The four phases of a four phase test are Setup, Exercise, Verify, and Teardown. In this case, you want to Setup the random numbe...

8 days ago | 0

Answered
In an assignment A(:) = B, the number of elements in A and B must be the same.
indexes(1) = find(abs(data.(field) - rangeLimits(1)) < tolerance); indexes(2) = find(abs(data.(field) - rangeLimits(2))...

8 days ago | 0

Answered
why Normal Distribution with Histogram not matching?
Use: histogram(Cp(:,Distribution_tap),30, 'Normalization', 'pdf')

8 days ago | 0

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Answered
Is it possible to fit with a Fourier series with more than 8 terms?
Curve Fitting Toolbox includes standard library models that contain between 1 and 8 Fourier terms. You could define a custom fit...

8 days ago | 0

Answered
How do I get more colours for scatter plot?
See the description of the c input argument on the documentation page for the scatter function. You want the "Assign different c...

8 days ago | 1