John Petersen
Last seen: 3 days ago
Autonomous Solutions, Inc.
177 total contributions since 2011Control systems engineer with PhD in EE at Autonomous Solutions and I love to ski, run and bike trails.
Professional Interests: Control systems, Localization/Navigation, Estimation, Electronic Design, Sensor Fusion
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Question
How can I determine where or if a bus is used in a simulink model?
I have a complex simulink model that has dozens of busses defined. Some busses are identical but with different names. I have f...
5 days ago | 1 answer | 0
1
answerQuestion
How to convert a layered structure into arrays.
I have a structure like this A.a.b.first, A.a.b.second, A.a.b.third A.c.d.first, A.c.d.second, A.c.d.third A.e.f.first, A.e.f...
1 month ago | 2 answers | 0
2
answersQuestion
Variable Not fully defined on some execution path error
I have some code that is inside a simulink block that gets an error when it's compiled. It says a variable is not fully defined ...
1 month ago | 1 answer | 0
1
answerQuestion
How do I plot the progress of fmincon to see the convergence of the approximation?
I want to see the output at each iteration of the optimization. I am solving for MPC and want to plot the entire future solution...
6 months ago | 0 answers | 0
0
answersDoes a single nodelocked license file support multiple matlab versions
Yes, this is possible. See https://www.mathworks.com/matlabcentral/answers/99348-is-it-possible-to-have-multiple-releases-of-...
7 months ago | 0
Error using cd Cannot CD to 7364 (Name is nonexistent or not a directory).
You are changing directories in the first for loop so that by the time you get in to the second for loop you are not starting in...
7 months ago | 0
How to keep the slider position the same after retrieving its value?
It's not a great idea to be using any globals in here. My guess is that roadA has the value of 5 and that's why slider_input =...
1 year ago | 0
Question
How do I change a configuration parameter for all simulink blocks in my model?
I recently upgraded to 2016b from 2015a and now I'm getting many warnings about units inconsistency. I don't use or care about ...
3 years ago | 0 answers | 0
0
answersQuestion
Can I index into a timeseries using time?
I have a timeseries and I want to index into the timeseries using time to get the data. Is there an elegant way or do you have t...
4 years ago | 1 answer | 0
1
answerQuestion
How do I control the size of a checkbox in a programmatic GUI?
I have a programmatic GUI and I'm trying to change the size of my checkboxes, but I can't get it to change. I've tried changing...
4 years ago | 1 answer | 0
1
answerQuestion
How to index every field of a structure and reassign to a structure with a single element in each field
I have a structure where every field is an array of the same length. I need to pass this structure on but only with a single ele...
4 years ago | 2 answers | 1
2
answersQuestion
How do I get my text to center vertically in a uicontrol textbox?
I am creating a GUI programmatically and I have a panel that I am displaying text boxes. How do I get my text boxes to display t...
4 years ago | 1 answer | 1
1
answerhow do I print a txt file of integers and floats?
Thank you for your input and suggestions! I have finally come up with this Ad = double(A); % cast the int to a double d...
4 years ago | 0
Question
how do I print a txt file of integers and floats?
I have tried in vain to write a text file of a mix of ints and floats. Suppose I have A = nx1 ints, and B = nx1 floats I want ...
4 years ago | 4 answers | 0
4
answersQuestion
How do I rename fields of a structure array?
Say I have a structure array such as A = 1x49 struct array with fields: a b c d H...
5 years ago | 5 answers | 0
5
answersQuestion
How do I assign the same value to every field, including nested fields of a structure?
Say I have a structure which has an unknown number of fields and each field may or may not have subfields. I want to assign a ce...
5 years ago | 1 answer | 0
1
answerQuestion
How do I run a script from a GUI that will run in the 'base' workspace?
I have a simulink model that uses a lot of variables from the base workspace. Now I am making a GUI that runs the model, but I w...
5 years ago | 2 answers | 1
2
answersQuestion
Structured Cell array assignment question
If I have something like A(1).a = {c}; A(2).a = {d}; and B(1).a = {e}; B(2).a = {f}; and want to assign ...
5 years ago | 2 answers | 0
2
answersQuestion
xlsread doesn't recognize file has changed
I have a .xlsx file that I read with xlsread. However, if I change the file and call it with xlsread again, it returns the old v...
5 years ago | 0 answers | 0
0
answersQuestion
How do I make assignments to my workspace using variable names and values in a spreadsheet?
I have an excel file that has names of structures in the top row, names of fields of those structures in the 2nd row and in the ...
5 years ago | 2 answers | 0
2
answersSimulink model does not "continue" after a "pause" by using set_param commands.
Your sim stops because of the pause. When you press play, it continues for one cycle and then is told to pause again in your ass...
5 years ago | 0
Question
Fill a listbox with the text of a set of enumerations
I have a listbox in a GUI that I want to populate using enumerations. My class of enumerations might be something like mye...
5 years ago | 1 answer | 0
1
answerProblem saving cell to txt file
The error is telling you that you can't use cells in your print function. That's because cell arrays can be different lengths, a...
5 years ago | 0
| accepted
How to use LQR and code generation?
The 'work around' is to write your own Ricatti Eq Solver.
6 years ago | 0
Question
Turn a cellarray into a single array.
I have a cell array, sig, with varying lengths of data in each cell. For example (on a simplified scale) sig = [{1}; {[2 ...
6 years ago | 2 answers | 0
2
answersHow to convert step varying signal into linear signal(gradual rise and fall)>
One way to do it is to sample the step varying signal at each step and then use the result or you could fit a spline or polynomi...
6 years ago | 0
Function for Script. I need to write a Function that selects the positive and negative numbers from a matrix. How to write this?
a = 0.5 - rand(3,3); %Positive numbers a(a>=0) % negative numbers a(a>0)
6 years ago | 0
Substituting a number for NaN in anonymous function
You have .*f(x) in g(x), which is still giving you a NaN
6 years ago | 1
Solving steady state Kalman riccati equation
Just write out the equations. If it's 2x2 it shouldn't be too hard. Q and R are almost always diagonal. P is symmetric, so thes...
6 years ago | 0
Extended Kalman Filter converges to wrong values (super simple model)
You have a constant dt used in the filter, but the simulation is variable step. This will cause problems with your predictor. ...
6 years ago | 0
| accepted
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