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.

Answered

Array indices must be positive integers or logical values.

Nn=1:2:30; This is valid MATLAB code. Nn(i)=60; As long as i has been defined as an array containing only positive integer va...

Array indices must be positive integers or logical values.

Nn=1:2:30; This is valid MATLAB code. Nn(i)=60; As long as i has been defined as an array containing only positive integer va...

3 hours ago | 0

Answered

errors in sortrow in matlabr2020

"Column sorting vector must contain integers with absolute value between 1 and the number of columns in the first argument." Ho...

errors in sortrow in matlabr2020

"Column sorting vector must contain integers with absolute value between 1 and the number of columns in the first argument." Ho...

5 hours ago | 0

Answered

function used for grading, :how do i get it to work?

I would do my input argument checking up front. Why go through the effort of classifying data that I know is invalid? if mark >...

function used for grading, :how do i get it to work?

I would do my input argument checking up front. Why go through the effort of classifying data that I know is invalid? if mark >...

5 hours ago | 0

Answered

Error using quad (line 70) The integrand function must return an output vector of the same length as the input vector. Error in sprawozdanie1 (line 37) Ssr=quad(x1,-0,6*pi);

x1=@(t)x; x is a numeric vector. That vector is not necessarily the same size or shape as the array t that quad passes into you...

Error using quad (line 70) The integrand function must return an output vector of the same length as the input vector. Error in sprawozdanie1 (line 37) Ssr=quad(x1,-0,6*pi);

x1=@(t)x; x is a numeric vector. That vector is not necessarily the same size or shape as the array t that quad passes into you...

6 hours ago | 0

Answered

Is there any limitation with fimplicit and fimplicit3 when functions have sqrt ?

Let's look at the value of your function at one of the corners of the region on which you want to plot: R = 0.35; L = 0.264;...

Is there any limitation with fimplicit and fimplicit3 when functions have sqrt ?

Let's look at the value of your function at one of the corners of the region on which you want to plot: R = 0.35; L = 0.264;...

6 hours ago | 1

Answered

Finding local minimums/maximums for a set of data

For more recent releases take a look at the islocalmin, islocalmax, and (perhaps) detrend functions.

Finding local minimums/maximums for a set of data

For more recent releases take a look at the islocalmin, islocalmax, and (perhaps) detrend functions.

1 day ago | 0

Answered

Eigenvector different to expected using eig

A=[1.5 -0.5; -1 1]; [Vec,Val]=eig(A) What does the eig function return? From its documentation: "[V,D] = eig(A) returns diag...

Eigenvector different to expected using eig

A=[1.5 -0.5; -1 1]; [Vec,Val]=eig(A) What does the eig function return? From its documentation: "[V,D] = eig(A) returns diag...

1 day ago | 1

| accepted

Answered

Extreme difference between the value of a function and the result in matlab

One of the terms in your expression involves b^8. For b = 30000 what is the value of that term? b = 30000; b8 = b^8 That valu...

Extreme difference between the value of a function and the result in matlab

One of the terms in your expression involves b^8. For b = 30000 what is the value of that term? b = 30000; b8 = b^8 That valu...

1 day ago | 0

Answered

what does MatLab Home license cover?

For official answers to these licensing questions please contact Customer Service using the "Contact Support" link on the Suppor...

what does MatLab Home license cover?

For official answers to these licensing questions please contact Customer Service using the "Contact Support" link on the Suppor...

1 day ago | 0

Answered

sym error in define functions

As the error message states, "To evaluate character vectors and strings representing symbolic expressions, use 'str2sym'." So u...

sym error in define functions

As the error message states, "To evaluate character vectors and strings representing symbolic expressions, use 'str2sym'." So u...

1 day ago | 0

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Answered

How to write a short syntax for the legend?

Set the DisplayName property of each line just like you set the LineWidth. Then legend show will make the legend appear and use ...

How to write a short syntax for the legend?

Set the DisplayName property of each line just like you set the LineWidth. Then legend show will make the legend appear and use ...

1 day ago | 0

Answered

hour of datenum type

What is the full and exact text of the error messages they receive? Show all the text displayed in red (and if there is any text...

hour of datenum type

What is the full and exact text of the error messages they receive? Show all the text displayed in red (and if there is any text...

2 days ago | 0

Answered

Solve system of linear equations ...matrix output is not as expected

A being a 9-by-9 matrix is correct. syms A11 A12 A13 A21 A22 A23 A31 A32 A33 real; eq1 = A11*-0.001179+A12*-6.581+A13*0.008...

Solve system of linear equations ...matrix output is not as expected

A being a 9-by-9 matrix is correct. syms A11 A12 A13 A21 A22 A23 A31 A32 A33 real; eq1 = A11*-0.001179+A12*-6.581+A13*0.008...

2 days ago | 0

| accepted

Answered

How can I do to enable zoom only for a specific axes?

Call zoom with an output. Call setAllowAxesZoom on that object. See the "Object Functions" section on the documentation page for...

How can I do to enable zoom only for a specific axes?

Call zoom with an output. Call setAllowAxesZoom on that object. See the "Object Functions" section on the documentation page for...

2 days ago | 0

Answered

Task: write matlab code for a class MinAngle which calculates the minimum angle between two bearings (bearing A and bearing B).

The assignment operator in MATLAB is =. The element-wise comparison operator is ==. But you should use neither of those in your ...

Task: write matlab code for a class MinAngle which calculates the minimum angle between two bearings (bearing A and bearing B).

The assignment operator in MATLAB is =. The element-wise comparison operator is ==. But you should use neither of those in your ...

2 days ago | 0

Answered

Switching between open files in editor by searching

There is an API you could potentially use for this sort of task. I have my installation of release R2019b open, so I'll just ope...

Switching between open files in editor by searching

There is an API you could potentially use for this sort of task. I have my installation of release R2019b open, so I'll just ope...

2 days ago | 0

Answered

Integral Function inside while loop only works for certain values. ArrayValued results in empty volumn vectors.

You probably want to recompute S *while* it is empty not *if* it is empty. Otherwise S could still be empty after the second vpa...

Integral Function inside while loop only works for certain values. ArrayValued results in empty volumn vectors.

You probably want to recompute S *while* it is empty not *if* it is empty. Otherwise S could still be empty after the second vpa...

3 days ago | 1

Answered

how do I take the matrix A and a vector with the indexes of the rows to be considered, and takes out a vector of the mean values?

function A(meanValue) = HW3Part3Function A(meanValue) = mean((A(1:2:end,:),2)) When you define your function, the function dec...

how do I take the matrix A and a vector with the indexes of the rows to be considered, and takes out a vector of the mean values?

function A(meanValue) = HW3Part3Function A(meanValue) = mean((A(1:2:end,:),2)) When you define your function, the function dec...

3 days ago | 0

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Answered

convert logical values to numeric values

What do you want the double array to represent? Just 0 and 1 instead on false and true? Use Jan's approach. 0 where there isn'...

convert logical values to numeric values

What do you want the double array to represent? Just 0 and 1 instead on false and true? Use Jan's approach. 0 where there isn'...

3 days ago | 0

Answered

Syntax Question, Why does this equal zero?

What happens if you compute it by hand? Start with the expression in the parentheses since they're at the top level of the opera...

Syntax Question, Why does this equal zero?

What happens if you compute it by hand? Start with the expression in the parentheses since they're at the top level of the opera...

4 days ago | 0

Answered

Can I assign a variable to a number in a matrix from another matrix?

There's a way to do this without creating 2*n individual variables. A = magic(7); E = eig(A); w = E(1:3); m = [3; 11; -7];...

Can I assign a variable to a number in a matrix from another matrix?

There's a way to do this without creating 2*n individual variables. A = magic(7); E = eig(A); w = E(1:3); m = [3; 11; -7];...

4 days ago | 0

Answered

Not Enough Input Arguments

Your function can be called with at most two inputs, and since it uses both inputs on the line you called out it must be called ...

Not Enough Input Arguments

Your function can be called with at most two inputs, and since it uses both inputs on the line you called out it must be called ...

4 days ago | 0

Answered

Convert Text into Date Format

If you have a number: x = 196307; datetime(100*x+1, 'ConvertFrom', 'yyyymmdd') If you have text: y = string(x); datetime(y,...

Convert Text into Date Format

If you have a number: x = 196307; datetime(100*x+1, 'ConvertFrom', 'yyyymmdd') If you have text: y = string(x); datetime(y,...

4 days ago | 1

Answered

represent a function in Matlab

Let's look at your function symbolically. xo = 400; yo = 7000; x = 260; y = 6954; a = 0.5; b =0.4; K = b*xo-a*yo; % t=...

represent a function in Matlab

Let's look at your function symbolically. xo = 400; yo = 7000; x = 260; y = 6954; a = 0.5; b =0.4; K = b*xo-a*yo; % t=...

4 days ago | 0

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Answered

Fit operation with defined variables

See the "Create Fit Options and Fit Type Before Fitting" example on the documentation page for the fit function. It uses the 'pr...

Fit operation with defined variables

See the "Create Fit Options and Fit Type Before Fitting" example on the documentation page for the fit function. It uses the 'pr...

4 days ago | 1

| accepted

Answered

Array indices must be positive integers or logical values.

If x only has one element, x(end-1) is an attempt to access element 0 of x. Arrays in MATLAB don't have an element 0. Their firs...

Array indices must be positive integers or logical values.

If x only has one element, x(end-1) is an attempt to access element 0 of x. Arrays in MATLAB don't have an element 0. Their firs...

5 days ago | 0

Answered

How to define these two functions?

The name gamma already has a meaning in MATLAB, and in fact it calculates the function you're trying to evaluate with your anony...

How to define these two functions?

The name gamma already has a meaning in MATLAB, and in fact it calculates the function you're trying to evaluate with your anony...

5 days ago | 1

| accepted

Answered

How do I calculate this definite integral in matlab

When I encounter a problem integrating, one of my first thoughts is to look at the function I'm trying to integrate over the int...

How do I calculate this definite integral in matlab

When I encounter a problem integrating, one of my first thoughts is to look at the function I'm trying to integrate over the int...

5 days ago | 1

Answered

use vector as input

So you want to compute the value of e and the time required to compute that value for each element of n? A couple of suggestions...

use vector as input

So you want to compute the value of e and the time required to compute that value for each element of n? A couple of suggestions...

5 days ago | 0

Answered

How to extend the colon operator for my own class

The colon function in MATLAB for numeric inputs does not return an iterator, it returns a vector. See the documentation page for...

How to extend the colon operator for my own class

The colon function in MATLAB for numeric inputs does not return an iterator, it returns a vector. See the documentation page for...

5 days ago | 0