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Steven Lord


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MathWorks

5.195 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
Help with simple bisection method function while loop
Let's say your function was: f = @(x) -x.^2; and your tolerance was 1e-6. Is the tolerance satisfied if I evaluate f at x = 1?...

alrededor de 9 horas ago | 0

Answered
Matlab Bisection Algorithm code
This bisect(sin(x),pi/2,1.5*pi,10^-6,100) attempts to call the sin function with the contents of the variable x as input and u...

alrededor de 11 horas ago | 1

Answered
error: Array indices must be positive integers or logical values.
m=(1/((kw(di)^2 ... There's no such thing as element 0.05 of an array in MATLAB. Perhaps you're missing a multiplication sign t...

alrededor de 13 horas ago | 0

Answered
Unwanted negative solution with ode solver
Either: specify the NonNegative option using odeset to control which components of the solution are not allowed to become negat...

alrededor de 15 horas ago | 0

Answered
Multi Dimension Matrix Elements multiplication
If you're using release R2020b or later, see the pagemtimes function.

alrededor de 18 horas ago | 0

Answered
ode45: use span of length 2
If you want to only evaluate the solution of your ODE at a specific set of times even if that set of times has only two elements...

alrededor de 18 horas ago | 0

Answered
Error: File: centraldiff.m Line: 1 Column: 11 Unbalanced or unexpected parenthesis or bracket
When you define your function, the function declaration line should include the names of the variables into which the input argu...

1 día ago | 0

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Answered
Making animatedlines that dynamically change linestyle depending on conditions
h = animatedline('LineStyle', '-'); axis([0 360 -1 1]) for x = 0:360 if mod(x, 30) == 0 addpoints(h, NaN, NaN); ...

1 día ago | 0

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Answered
Versions at End-of-Life
See the Road Map on the system requirements page. If there is a specific release and operating system combination not on that l...

1 día ago | 0

Answered
Multiply Even Variables in an Array
Hint: use logical indexing twice in the onle line of code that performs this replacement.

1 día ago | 0

Answered
Time difference in 'HH:mm:ss,SSSSSS' format
t0 = '15:30:25,123456' t1 = '16:45:30,123457' theFormat = 'hh:mm:ss.SSSSSS'; timeStart = duration(replace(t0, ',', '.'), 'I...

1 día ago | 1

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Answered
error in using the function fsolve to find steady state
Don't try using a numeric solver like fsolve on a function that returns symbolic answers. Use the solve function from Symbolic M...

1 día ago | 0

Answered
What are symbolic variables in MATLAB? How they are different from normally used variables?
Symbolic variables are instances of a class provided as part of Symbolic Math Toolbox. That documentation for MATLAB does not li...

2 días ago | 1

Answered
Password issues with downladed software
Have you contacted Springer directly to ask them for the password?

2 días ago | 0

Answered
Undefined function 'ln' for input arguments of type 'double'.
The natural logarithm function in MATLAB is named log not ln. There are also log10 and log2 functions listed in the See Also sec...

3 días ago | 1

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Answered
Computation on arrays using loops
Since you seem to be describing change point detection, see the ischange function and/or the Find Change Points task in the Live...

3 días ago | 1

Answered
Check if Lat, Lon coordinate fall inside a polyshape Polygon
I would vectorize the calculations. Let's make a simple polyshape: P = polyshape([0.75 0.3 -0.4 -0.1 -0.6 -0.3 0.5], [0.1 0.6 0...

3 días ago | 0

Answered
how to change order of legends?
You can specify the handles in a particular order when you create the legend. % Sample data x = 0:360; y1 = sind(x); y2 = c...

3 días ago | 0

Answered
How to highlight isolated nodes in a graph?
You want to highlight those nodes that are not connected to any other? G = graph(sprand(10, 10, 0.05), 'upper'); h = plot(G); ...

3 días ago | 1

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Answered
Assign placement choices to student identifying their top three
See the matchpairs function.

3 días ago | 0

Answered
how to normalize a matrix?????
Use the normalize function with a dim input and the 'range' normalization method.

3 días ago | 0

Answered
Implementation of the feedforwardnet Neural Network
How are you handling the preprocessing functions and postprocessing functions? net = feedforwardnet([2]); net.inputs{1}.proces...

3 días ago | 0

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Answered
display biograph in GUI axes
If you want to display a graph in an app or GUI axes, consider building a graph or digraph object and calling plot on it. I beli...

3 días ago | 0

Answered
Group data in bins
If you just need to know in which bin each element falls, use discretize. E = 0:11; x = 10*rand(20, 1); bin = discretize(x, E...

3 días ago | 0

Answered
MatLab Interface font size
Change the font preferences.

5 días ago | 0

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Answered
Finding Mode and Median Without Mode and Median Function
If I gave you a list of numbers: A = randi(10, 1, 7) How would you compute the mode and median of A with pencil and paper (or ...

5 días ago | 1

Answered
Using "fit" function to create a fit type and fit a curve with a function I created
From the description of the 'independent' name-value pair input argument on the documentation page for the fittype function: "In...

5 días ago | 0

Answered
movmean and mean comparasion
Nope. Let's look at an example: BW = magic(4) curve2 = mean(BW, 1) curve = movmean(BW, 1, 1) The movmean call slides a w...

6 días ago | 0

Answered
Can't create/open txt files
Does the file D:\Work\Stage\filename.txt exist when you try to open it for writing? What do these commands return? filename = '...

7 días ago | 0

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