Rank: 866 based on 141 downloads (last 30 days) and 7 files submitted
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Per Sundqvist

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Company/University
Chalmers Tekniska Högskola

Personal Profile:
Professional Interests:
quantum and mathematical physics

 

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Files Posted by Per View all
Updated   File Tags Downloads
(last 30 days)
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09 Jan 2009 Screenshot Exponential fit, without start-guess Fits 1) f=s1+s2*exp(-t/s3) or 2) f=s1+s2*exp(-t/s3)+s4*exp(-t/s5) to numerics, without startguess Author: Per Sundqvist nonlinear, exponential, least square, fit, exact, initial guess 49 13
  • 3.7
3.7 | 11 ratings
12 Nov 2008 3D Data Interpolation 3D interpolation using modified 4-point vector Newton interpolation Author: Per Sundqvist approximation, interpolation, 3d interpolation, newton, nonuniform, mathematics 14 5
  • 2.5
2.5 | 6 ratings
16 Jan 2008 Screenshot erfi function Imaginary error function (could be complex) using matlab's incomplete gamma function gammainc Author: Per Sundqvist imaginary error funct..., complex, gaussian, integral 18 8
  • 3.0
3.0 | 4 ratings
13 Jan 2005 Orthogonal Linear Regression Fits a line y=p0+p1*y to a dataset (xdata,ydata) in an orthogonal way. Author: Per Sundqvist approximation, interpolation, linear regression, interpolation orthogo..., least squares fit 16 11
  • 3.25
3.2 | 9 ratings
22 Nov 2004 Screenshot Points Inside polygone Finds those points (xi,yi) who are inside the polygon, defined by the vectors (x,y) Author: Per Sundqvist approximation, interpolation, 2d contour, random, find, polygon 7 3
  • 2.0
2.0 | 2 ratings
Comments and Ratings by Per
Updated File Comments Rating
03 Nov 2008 Exponential fit, without start-guess Fits 1) f=s1+s2*exp(-t/s3) or 2) f=s1+s2*exp(-t/s3)+s4*exp(-t/s5) to numerics, without startguess Author: Per Sundqvist

HI, B. Roossien. I'm not sure what kind of help you want. The code is standard but assumes perhaps that you are a bit familiar with matlab. nargin<4 means that your input arguments are 3 and you will then get options as specified, later on, at the end of the program used in the matlab function lsqcurvefit. Maby I should tell that t and f should be vectors of the same size? Or do you want me to explain the theoretical model? Its lengthy though...

As well I realize now that I in the beginning of the program should have wrote:
t=t(:);
f=f(:);
[t,ix]=sort(t);
f=f(ix);
%to make time and function f vectors sorted column vectors in case they have a funny formate like matrices.
/Per

Comments and Ratings on Per's Files View all
Updated File Comment by Comments Rating
07 Jan 2014 Koch Star Eigenvalues Gets the coordinates of kocks snowflake and creates the poygone in femlab3.0. Author: Per Sundqvist amir

25 Jun 2013 erfi function Imaginary error function (could be complex) using matlab's incomplete gamma function gammainc Author: Per Sundqvist Del Águila, Javier

Thank you so much

09 Jun 2013 Orthogonal Linear Regression Fits a line y=p0+p1*y to a dataset (xdata,ydata) in an orthogonal way. Author: Per Sundqvist G. Neto, Guilherme

13 Mar 2013 erfi function Imaginary error function (could be complex) using matlab's incomplete gamma function gammainc Author: Per Sundqvist Chris

Thanx man.
You saved my life!

19 Jan 2013 Cylinder Between 2 Points Generalization of the MATLAB function cylinder Author: Per Sundqvist Chris

Very good function, it was very helpful

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