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Craig Cowled


Queensland University of Technology

Last seen: 1 day ago Active since 2011

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  • 3 Month Streak
  • Thankful Level 3
  • Knowledgeable Level 2
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Question


importfile regexp thousands separator returns NaN when negative
I used "Import Data" to generate a function importfile for importing a csv file. Unfortunately, the function returns NaN for ev...

4 years ago | 1 answer | 0

1

answer

Answered
Is it possible to make a manual Nyquist plot using polar(theta,rho)
Jeffrey, I usually keep my data in one complex vector rather than having two vectors (i.e., mag & phase). Then it's a simple th...

11 years ago | 0

Question


how to pass multiple values of x to objective function in GA / Patternsearch
I'm looking for ways to speed up the computation of my optimisation process. I've already used the PROFILE command to pinpoint ...

11 years ago | 1 answer | 0

1

answer

Answered
Genetic Algorithm options 'PopInitRange' not working
Alan, thank you for such a good explanation. Cleared it up for me nicely.

11 years ago | 0

Question


Genetic Algorithm options 'PopInitRange' not working
I am using GAOPTIMSET to establish an upper and lower bound for my initial population in a GA optimisation. I have abbreviate...

11 years ago | 2 answers | 0

2

answers

Answered
How do you share a variable from another function to be used in a different function?
Cordelle, I'm not going to re-write your code for you, but I will suggest that you read up on nested functions, here ... ht...

11 years ago | 0

| accepted

Answered
power spectrum VS amplitude of FFT function
Power = 20 * log10(abs(FFT))

11 years ago | 0

Answered
Restarting Genetic Algorithm after Crash
Many thanks yet again, Alan. Will write a little function to handle the crash and restart the GA. As for patternsearch, I mi...

11 years ago | 0

Answered
Matlab crashes when calling dll
Try using 'loadlibrary'.

11 years ago | 0

Question


Restarting Genetic Algorithm after Crash
I'm using the GA to update my Finite Element Model. The fitness function I am using is computationally expensive and takes 4sec...

11 years ago | 2 answers | 0

2

answers

Answered
Use of PSD functions to obtain FRFs
I thought I should tie up a loose end with this question. I discovered that the data acquisition from my impact hammer was faul...

11 years ago | 1

Answered
Curve fitting a complex function using cftool
MattJ, not sceptical ... always worthwhile to know the intrinsic quirks of an algorithm. I used your code and compared the di...

11 years ago | 0

Answered
Curve fitting problem and strange message
Fei, if the "change in residuals is less than tolerance" then this is an indication that you have a reasonably good fit. I ha...

11 years ago | 0

Answered
genetic algorithm error not enough input arguments
Hey, what do you know, it worked!! Btw, your recommendation of using LSQNONLIN was the right call too. Although the GA wor...

11 years ago | 0

Answered
genetic algorithm error not enough input arguments
Alan, Thank you for taking the time to answer this in so much detail! Point taken regarding the choice of optimization too...

11 years ago | 0

Question


genetic algorithm error not enough input arguments
function deltaH = curvefit_H_2modes(w1,w2,m1,m2,c1,c2) load('file.mat'); z = -(x.^2) .* ((1 ./ ((w1.^2 * m1) -...

11 years ago | 4 answers | 0

4

answers

Answered
How to Fix this Error!
Send this to Matlab Support. Obviously their help file has the wrong code.

11 years ago | 0

Answered
RMS question plss help me
Mohd, if you have the Signal Processing Toolbox, you can use the _rms_ function like this: X = [0.234 0.2338 0.255 3.456 5....

11 years ago | 0

Answered
Curve fitting a complex function using cftool
I just noticed another question on the forum in which someone suggested to use _mldivide_. I'll have a look at this when I get ...

11 years ago | 0

Answered
how to acces and change value inside transfer function inside a loop
Kobi, I tried running your code and got an error message. It looks like you missed a space between G.den{1,1} and (k) in the li...

11 years ago | 0

| accepted

Answered
pseudorandomise vectors in an array
Doug, I use a function that was developed by Jos, called _allcomb_. You can find it at the following link <http://www.mathworks...

11 years ago | 0

| accepted

Answered
How can I generate random numbers with constraints?
I think you have actually answered your own question. If x = randi([3 18], 7); gives you a 7 x 7 matrix of random numbers betwe...

11 years ago | 0

Question


bar3 width depend on zdata?
Ok, so I know how to make the colours on my bar graph depend on zdata .. h = bar3(data); for ii = 1:length(h) zdata =...

11 years ago | 0 answers | 0

0

answers

Answered
Boxplot with time on x axis
Found the answer ... Need to use 'positions' like this boxplot(Y,'positions',X)

11 years ago | 4

| accepted

Answered
Excel Date Format to Matlab Number Array
Have you tried using datevec? Take one of the cells as an example ... '02/03/2013'. >> datevec('02/03/2013','mm/dd/yyyy')...

11 years ago | 0

| accepted

Question


Boxplot with time on x axis
Does anybody know how to obtain a boxplot with time on the x axis? I have collected experimental observations at irregular in...

11 years ago | 1 answer | 1

1

answer

Question


Curve fitting a complex function using cftool
I'm using the cftool toolbox to find fits for a complex valued transfer function. The toolbox clearly can't handle a complex nu...

11 years ago | 3 answers | 0

3

answers

Question


Use of PSD functions to obtain FRFs
Hi, I am doing some modal analysis on a steel structure and have encountered some troubling issues while using Matlab's Power...

12 years ago | 2 answers | 1

2

answers