# Bill Tubbs

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**Content Feed**

Efficiently calculate exponentially weighted moving averages of matrix?

I find the easiest way is to use a discrete filter. But the input data is in columns here not rows: x = [0 1 1 1 1; 0 0 1 1 1]...

2 months ago | 0

Question

How to index the values of an array using a series of rows, column indices?

Couldn't find an answer about this and it is not mentioned in the Matlab documentation page on array indexing. I want to know h...

3 months ago | 1 answer | 0

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answerQuestion

Efficient algorithm to compute only the most probable sequences of a random variable out of all possible sequences

I'm looking for a better way to compute the possible sequences of a random variable whos value at time k is given by. x(k) = 1 ...

3 months ago | 3 answers | 1

### 3

answersQuestion

Waterfall plot not showing correctly

I think this is an undesirable feature of the waterfall plot function and I'm posting it here so that others don't spend as long...

3 months ago | 0 answers | 0

### 0

answersQuestion

Special characters in m-file comments are being removed/replaced

I've noticed that special charactes such as 'Γ' and '│' that I sometimes use in comments in m-files are being removed: % Comput...

3 months ago | 0 answers | 0

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answersHow to add variable names for each column when using array2table

I wrote a function to do it: function T = array2table_with_name(X, label, sep) % T = array2table_with_name(X, label) converts ...

3 months ago | 0

Question

Best way to generate an array of all possible integer numbers for a given base and number of digits

I want to prepare an array that contains all combinations in rows of possible sequences represented by an d-digit number of base...

4 months ago | 1 answer | 0

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answerCRL:"Simulation Target IPP BLAS" cannot be found in the registry

Problem was solved for me on Mac OS X by closing MATLAB and all Simulink files and restarting.

4 months ago | 0

How to construct a cell array containing a power series of a matrix

Here is a solution using cellfun: results = cellfun(@(i) A^i, num2cell(1:n), 'UniformOutput', false)

4 months ago | 0

Question

How to construct a cell array containing a power series of a matrix

I want to compute the following power series of a square matrix A (as a preliminary step to constructing a larger matrix using t...

4 months ago | 1 answer | 0

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answerBypassing the internal (Linear) observer in MPC toolbox 3

Might be 10 years too late but I had this question and it looks like you can set the following check box below in the Simulink M...

4 months ago | 0

How to deal with Extended Kalman Filter in Simulink when my state transition function is given in continuous time form?

Check out the examples in the documentation here: https://www.mathworks.com/help/control/ref/extendedkalmanfilter.html The exa...

5 months ago | 0

Simulink: There is no solver registered as 14.

I don't know exactly what caused this error but I found I could run the msfcn_limintm.m example from the S-functions in the docu...

5 months ago | 0

How are structs handled when passed to a function?

Seems that MATLAB makes a complete copy of a struct when it is passed to a function if any element is changed by the function (s...

5 months ago | 0

Question

Unable to detect datetime or duration data using readtimetable with a seconds index

Here is a toy example of my problem: % Create a timetable with a seconds index data = timetable(seconds(1:3)', randn(3,1), ran...

5 months ago | 1 answer | 1

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answerFind the First element that satisfies a condition

If you only want to find the locations in A where the condition is true and then index those values you can use find: >> elemen...

5 months ago | 0

What is the 'MeasurementFcn1Inputs' input on the Extended Kalman Filter Simulink block?

I found the problem. I was using the same function (robot_outputs) for the NLMPC and the EKF: function y = robot_outputs(x,u) ...

6 months ago | 0

| accepted

Question

What is the 'MeasurementFcn1Inputs' input on the Extended Kalman Filter Simulink block?

I'm trying to implement an Extended Kalman Filter Simulink block similar to the example shown for the inverted pendulum here whi...

6 months ago | 1 answer | 0

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answerGet a subset of columns from a timeseries object as a timeseries

Here is my answer to illustrates the timetables solution proposed by @dpb in the comments above. u = timetable(seconds(t),u1,u2...

6 months ago | 0

Question

Get a subset of columns from a timeseries object as a timeseries

I have a timeseries containing data for 4 variables: Ts = 0.2; nT = 50; t = Ts*(0:nT-1)'; u1 = 50*idinput(nT); u2 = 50*idinp...

6 months ago | 2 answers | 0

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answersQuestion

How to insert the 'double R' symbol in LiveScript (space of real numbers)

Anyone know how to get this symbol in the LiveScript equation editor? MS Equation editor equivalent: \doubleR Latex: $\mat...

7 months ago | 1 answer | 0

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answerQuestion

Is it possible to solve multiple linear systems of equations in parallel with one matrix operation?

I'm wondering if there's a way to do the following calculations in one go (i.e. without the for loop). V = nan([na nv]); for i...

7 months ago | 0 answers | 0

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answersQuestion

How to replace elements of a cell array using a containers.Map

I have a cell array of VariableNames that Matlab created when reading a csv file. I want to change them to my own choice of nam...

8 months ago | 2 answers | 0

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answersSolve equation that has a complex subexpression

I just discovered that you can also solve this numerically with vpasolve: syms s omega G(s) assume(omega > 0) G(s) = 10/(s*(1...

10 months ago | 0

Question

How to find the 'troughs' using peak finder in Simulink Scope

I've been using the Peak Finder Measurements tool in the Simulink scope output to find the peak of the system responses. But if...

10 months ago | 1 answer | 0

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answerHow to check if two transfer functions are the same?

Based on comments from Paul above I offer these functions as a solution: function c = is_equal_tf(G1,G2) c = almost_zero_s...

11 months ago | 0

Question

Basic math operations on contents of a cell array

Is there any reason why basic math operations don't work with cell arrays? Seems to me it would extremely useful and efficient ...

11 months ago | 2 answers | 0

### 2

answersQuestion

Best way to resample the output of a Simulink simulation with variable time step into a signal with a fixed sample time

I have a simulation model that runs with a variable timestep: (I don't want to change this) For the purpose of system identi...

11 months ago | 1 answer | 0

### 1

answerQuestion

How to turn off text interpreter when plotting timeseries objects

I am plotting timeseries objects using plot. My variable names include underscores (e.g. 'ABC_DEF') and I do not want these int...

11 months ago | 2 answers | 0

### 2

answersQuestion

Evaluate function over a mesh grid (without for loops)

Is there a way to evaluate a function that takes an [x, y] vector as input over a grid of points? Here is the function I want t...

11 months ago | 2 answers | 0