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Steven Lord

MathWorks

Last seen: Today 2002 年からアクティブ

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 to programmatically get the current/local time zone?
Do you want to create a datetime in the current time zone or do you want to know the current time zone? Those are two different ...

約2時間 前 | 0

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ODE45 requires more parameters than it should
That syntax, where you pass additional input arguments after the options structure, is an older syntax that is no longer documen...

約21時間 前 | 0

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For loop increment value
See the "Decrement Values" example on the documentation page for the for keyword. Though in the case you described, you don't ne...

約21時間 前 | 0

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Error using solve function
You have two variables in your cost function, y and int_l. Is y symbolic or a fixed value? If symbolic, with respect to which va...

1日 前 | 0

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Read text file, identify variables and rewrite some of the variables
I'd probably read this into a table array. A first pass at reading in this file is below. You probably want to customize the imp...

1日 前 | 0

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script for Unit delay block
Use the programmatic model editing tools.

1日 前 | 1

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Error bars with categorical data type
Let's say that your categorical x data contains values apple, banana, and cherry. When the error bars are plotted with errorbar,...

2日 前 | 0

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Change from 2022 to 2021 Plotting Issues
The ability to plot table arrays by passing them as inputs to the plot function was introduced in release R2022a as stated in th...

2日 前 | 1

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Can't find matlab.exe file
The MATLAB Runtime is not the MATLAB you'd use to develop MATLAB code. It is used to run deployed applications created by MATLAB...

2日 前 | 0

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Speed up MatlabFunction or use alternatives
Have you tried telling matlabFunction to skip trying to Optimize the code? cd(tempdir) syms a b c d positive syms x s = solv...

2日 前 | 0

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Detecting maximum with threshold
You may want to take a look at the islocalmax function.

3日 前 | 0

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matlab function syms slows down simulink model
Generate a MATLAB Function block using matlabFunctionBlock as shown on this documentation page.

3日 前 | 1

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left characters of a string
This wasn't an option when the question was originally asked, but the extractBefore function will work for both char vectors and...

4日 前 | 1

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How to solve dot indexing error in matlab reinforcement learning function "sim"?
The documentation page for the sim function in Reinforcement Learning Toolbox states that the env input argument must be a "rein...

4日 前 | 0

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Is it possible to get a time-dependent function as an output of an ODE solver?
Call ode45 with one output argument. Pass that output from ode45 and an array of times into the deval function to evaluate the s...

7日 前 | 0

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can MATLA read very large CSVs (>150GB)?
Use the tools in MATLAB for processing Large Files and Big Data.

7日 前 | 2

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Converting equations to first order system for ODE45
Let's look at your equations and your definition for your state vector. v' + r + phi'' = alpha1 + alpha2 r' + phi'' = alpha1 +...

7日 前 | 2

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Another question on eliminating for loops....
Take a look at the ndgrid function.

7日 前 | 0

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Remove array elements but also store the element indices that were not removed
Do you want the indices or the elements that weren't deleted? a = ["a", "b", "c", "d", "e" ,"f"]; u = [1 5]; indToKeep = setd...

7日 前 | 0

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I need to group certain hours of a day into day and night categories from my xlsx file in the format "yyyy-MM-dd'T'HH:mm:ss."
Let's look at a sample datetime. t = datetime('now') What time of day does that represent? tod = timeofday(t) Is that time o...

8日 前 | 0

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"\newline" "\mu" "pi", etc. doesn't work as intended on xticklabel of boxplot. It just prints as it is instead of printing a new line or μ or π.
Note that in order for tick labels to be interpreted as TeX or LaTeX the TickLabelInterpreter property needs to be set correctly...

8日 前 | 0

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How to resolve "RemoteAPIClient with no properties." error?
This is not an error. This successfully created an instance of the RemoteAPIClient object. I don't see any function named Remot...

8日 前 | 0

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List of all functions an their toolboxes
So you're looking for something like the function lists? This one is for MATLAB; each product has its own page like this. Are y...

8日 前 | 1

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imfinfo doesnt work in R2022b, it's bugged
Since you said imfinfo works for other files but not this one, I'm wondering if the file has somehow been corrupted or if it was...

8日 前 | 0

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Problem with if statements
Don't define a large number of variables whose names match the symbols for the elements and use a large collection of if stateme...

9日 前 | 1

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contradicting date identifier definitions in datestr and datetime
That's correct. This is mentioned in the description of the Format property on the datetime documentation page. If I recall cor...

9日 前 | 0

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How to perform these matrix calculations?
See the diff and cumsum functions.

9日 前 | 2

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Error-Variable might be used before it is defined
This would work if SpeedMaxOpt is a Constant property of the Global class or a Static method of that class that can be called wi...

10日 前 | 0

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Hist3 zero enteries
Instead of using hist3 I recommend you use histogram2 instead. It has some properties, including Normalization and ShowEmptyBins...

11日 前 | 0

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I am getting this preallocation warning
This is a Code Analyzer warning not a run-time warning. If you're not sure what preallocation is, why it can be important, or h...

11日 前 | 1

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