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David Heslop


19 total contributions since 2008

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Responded


Re: Fitting the equation y=a+bx+cx^d
Hi Bruno, thanks for the suggestion and the code. For a collection of test data the separable least-squares approach certainly s...

6 years ago | 3270 views

Posted


Fitting the equation y=a+bx+cx^d
Hi All, I've got some experimental data (x,y) which from theory I know I should be able to fit using the equation y=a+b.*x+c.*x....

6 years ago | 3270 views

Responded


Re: Fitting a (hyper)ellipsoid to data
Thank you Roger for your advice, unfortunately, I cannot assume that the principle axes are aligned with the coordinate axes. Ho...

6 years ago | 6854 views

Posted


Fitting a (hyper)ellipsoid to data
Dear All, I have a (hopefully noise free) collection of points which should all lie on the surface of an ellipse / ellipsoid / h...

6 years ago | 6854 views

Responded


Re: Fitting the hyperbola Ax+Bxy+Cy+D=0 to experimental data
Hi Torsten, I found the problem, I wasn't visualizing the result in a very sensible way. What I thought was mis-fit was simply t...

7 years ago | 11467 views

Responded


Re: Fitting the hyperbola Ax+Bxy+Cy+D=0 to experimental data
Hi Steve, thanks for the advice. NULL does work very well in the case of zero noise, but as soon as I add some noise to the data...

7 years ago | 11467 views

Responded


Re: Fitting the hyperbola Ax+Bxy+Cy+D=0 to experimental data
Hi Torsten Your right, (A,B,C,D) = (0,0,0,0) isn't what I want. I tried the method you suggested and it works really nicely. One...

7 years ago | 11467 views

Posted


Fitting the hyperbola Ax+Bxy+Cy+D=0 to experimental data
Hi all, I’m working with experimental data which is represented as a series of x and y values (both x and y are non-negati...

7 years ago | 11467 views

Responded


Re: What is the probability that random integers sum to a given value?
The question of how far I need to go into the tails is a bit of an open one. I'm using this approach in an attempt to identify a...

7 years ago | 7243 views

Responded


Re: What is the probability that random integers sum to a given value?
Thanks John, that is an extremely demonstrative piece of code, Dave

7 years ago | 7243 views

Responded


Re: What is the probability that random integers sum to a given value?
Dear All, It is an interesting point that the replacement will have little effect given a large enough value of N. As Tristram m...

7 years ago | 7243 views

Responded


Re: What is the probability that random integers sum to a given value?
Hi Bruno, sorry if this led to confusion, I hoped that I had made this aspect explicit in the original problem when stating that...

7 years ago | 7243 views

Responded


Re: What is the probability that random integers sum to a given value?
Thanks for your input, the sampling it assumed to be without replacement. The problem derives from attempting to form significan...

7 years ago | 7243 views

Posted


What is the probability that random integers sum to a given value?
Can anybody suggest an efficient method to approach this problem? Choose W unique random integers drawn from 1 to N, what is th...

7 years ago | 7243 views

Responded


Re: Using normfit with weighted data values
Hi Peter, thanks for your detailed reply. I was using an old version of normfit, I've now updated and things are much clearer wi...

8 years ago | 4581 views

Posted


Using normfit with weighted data values
Hi All, I’m trying to use "normfit" to estimate the 95% confidence limit for the mean of a series of normally distributed ...

8 years ago | 977 views

Posted


Using normfit with weighted data values
Hi All, I’m trying to use "normfit" to estimate the 95% confidence limit for the mean of a series of normally distributed ...

8 years ago | 4581 views

Responded


Re: Specifying the value at which the x and y axes cross
Thanks, that's just what I needed, Dave

9 years ago | 2567 views

Posted


Specifying the value at which the x and y axes cross
Hi, can anyone offer advice on how to adjust the positions of axes in matlab plots. By default the x and y axes always cross at ...

9 years ago | 2567 views