# lstsq

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## lstsq

 Hi, I would like to use lstsq to fit a curve y using a simple linear combination of three spectra (spectrum1-3 see below). Since the program below always crashes, I played around with it and found that it does not crash if I copy the contents of the array "spectrum2" to the array "spectrum3" (using spectrum3[0:36]=spectrum2[0:36]). But as soon as I change one of the numbers in array "spectrum3" it crashes again. What is the mistake? Thanks, Gregor from numpy import * from numpy.random import normal from pylab import * t = arange(205, 241, 1.0) #spectrum1 spectrum1=array([-25.35,-30.85,-34.6,-36.5,-36.75,-35.95,-35.2,-34.2,-33.6,-33.55,-33.8,-34.2,-34.2,-34.8,-35.4,-36.25,-36.6,-36.85,-36.55,-35.85,-35.05,-33.55,-31.7,-29.6,-27.15,-24.1,-21.5,-18.95,-16.4,-13.85,-11.45,-9.43,-7.76,-6.24,-4.81,-3.88]) #spectrum2 spectrum2=array([8.08,5.37,1.24,-3.07,-6.02,-8.84,-11.2,-13.05,-14.85,-17.75,-17.5,-18,-18.35,-18.65,-18.15,-17.45,-17.15,-16.3,-15,-13.15,-11.57,-9.76,-7.98,-5.79,-3.73,-2.37,-0.61,0.08,0.15,1.17,0.73,0.77,0.38,0.56,0.28,0.64]) #spectrum3 spectrum3=array([-25.8,-21.45,-18.0,-15.59,-12.82,-10.41,-8.41,-6.58,-4.99,-3.85,-2.62,-1.74,-1.02,-0.5,-0.13,0.17,0.03,-0.08,-0.32,-0.35,-0.48,-0.75,-1.12,-1.31,-1.5,-1.55,-1.17,-1.04,-0.72,-0.46,-0.14,0.21,0.01,0.23,0.03,-0.22]) #make curve y y=0.8*spectrum1+0.1*spectrum2+0.2*spectrum3+ normal(0.0, 1.0, len(t)) from numpy.linalg import lstsq Nparam = 3 A=zeros((len(t), Nparam),float) #helix A[:,0]=spectrum1 #beta A[:,1]=spectrum2 #coil A[:,2]=spectrum3 (p, residuals, rank, s) = lstsq(A,y) #A=p*A #fit = A[:,0]+A[:,1]#+A[:,2] #plot (t, y) #plot (t, fit) _______________________________________________ SciPy-user mailing list [hidden email] http://projects.scipy.org/mailman/listinfo/scipy-user
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## Re: lstsq

 Gregor Hagelueken wrote: > Hi, > > I would like to use lstsq to fit a curve y using a simple linear > combination of three spectra (spectrum1-3 see below). Since the > program below always crashes, I played around with it and found that > it does not crash if I copy the contents of the array "spectrum2" to > the array "spectrum3" (using spectrum3[0:36]=spectrum2[0:36]). But as > soon as I change one of the numbers in array "spectrum3" it crashes again. > > What is the mistake? > > Thanks, > Gregor > > from numpy import * > from numpy.random import normal > from pylab import * > > t = arange(205, 241, 1.0) > > #spectrum1 > spectrum1=array([-25.35,-30.85,-34.6,-36.5,-36.75,-35.95,-35.2,-34.2,-33.6,-33.55,-33.8,-34.2,-34.2,-34.8,-35.4,-36.25,-36.6,-36.85,-36.55,-35.85,-35.05,-33.55,-31.7,-29.6,-27.15,-24.1,-21.5,-18.95,-16.4,-13.85,-11.45,-9.43,-7.76,-6.24,-4.81,-3.88]) > #spectrum2 > spectrum2=array([8.08,5.37,1.24,-3.07,-6.02,-8.84,-11.2,-13.05,-14.85,-17.75,-17.5,-18,-18.35,-18.65,-18.15,-17.45,-17.15,-16.3,-15,-13.15,-11.57,-9.76,-7.98,-5.79,-3.73,-2.37,-0.61,0.08,0.15,1.17,0.73,0.77,0.38,0.56,0.28,0.64]) > #spectrum3 > spectrum3=array([-25.8,-21.45,-18.0,-15.59,-12.82,-10.41,-8.41,-6.58,-4.99,-3.85,-2.62,-1.74,-1.02,-0.5,-0.13,0.17,0.03,-0.08,-0.32,-0.35,-0.48,-0.75,-1.12,-1.31,-1.5,-1.55,-1.17,-1.04,-0.72,-0.46,-0.14,0.21,0.01,0.23,0.03,-0.22]) > > #make curve y > y=0.8*spectrum1+0.1*spectrum2+0.2*spectrum3+ normal(0.0, 1.0, len(t)) > > from numpy.linalg import lstsq > Nparam = 3 > A=zeros((len(t), Nparam),float) > > #helix > A[:,0]=spectrum1 > #beta > A[:,1]=spectrum2 > #coil > A[:,2]=spectrum3 > > (p, residuals, rank, s) = lstsq(A,y) > > #A=p*A > #fit = A[:,0]+A[:,1]#+A[:,2] > #plot (t, y) > #plot (t, fit) > ------------------------------------------------------------------------ > > _______________________________________________ > SciPy-user mailing list > [hidden email] > http://projects.scipy.org/mailman/listinfo/scipy-user>   Hi, This works for me on Linux x86_64, Python 2.5 and '1.1.0.dev5133'. What are you using and what is the actual error message? Bruce _______________________________________________ SciPy-user mailing list [hidden email] http://projects.scipy.org/mailman/listinfo/scipy-user
 Bruce Southey wrote: ```Gregor Hagelueken wrote: ``` ```Hi, I would like to use lstsq to fit a curve y using a simple linear combination of three spectra (spectrum1-3 see below). Since the program below always crashes, I played around with it and found that it does not crash if I copy the contents of the array "spectrum2" to the array "spectrum3" (using spectrum3[0:36]=spectrum2[0:36]). But as soon as I change one of the numbers in array "spectrum3" it crashes again. What is the mistake? Thanks, Gregor from numpy import * from numpy.random import normal from pylab import * t = arange(205, 241, 1.0) #spectrum1 spectrum1=array([-25.35,-30.85,-34.6,-36.5,-36.75,-35.95,-35.2,-34.2,-33.6,-33.55,-33.8,-34.2,-34.2,-34.8,-35.4,-36.25,-36.6,-36.85,-36.55,-35.85,-35.05,-33.55,-31.7,-29.6,-27.15,-24.1,-21.5,-18.95,-16.4,-13.85,-11.45,-9.43,-7.76,-6.24,-4.81,-3.88]) #spectrum2 spectrum2=array([8.08,5.37,1.24,-3.07,-6.02,-8.84,-11.2,-13.05,-14.85,-17.75,-17.5,-18,-18.35,-18.65,-18.15,-17.45,-17.15,-16.3,-15,-13.15,-11.57,-9.76,-7.98,-5.79,-3.73,-2.37,-0.61,0.08,0.15,1.17,0.73,0.77,0.38,0.56,0.28,0.64]) #spectrum3 spectrum3=array([-25.8,-21.45,-18.0,-15.59,-12.82,-10.41,-8.41,-6.58,-4.99,-3.85,-2.62,-1.74,-1.02,-0.5,-0.13,0.17,0.03,-0.08,-0.32,-0.35,-0.48,-0.75,-1.12,-1.31,-1.5,-1.55,-1.17,-1.04,-0.72,-0.46,-0.14,0.21,0.01,0.23,0.03,-0.22]) #make curve y y=0.8*spectrum1+0.1*spectrum2+0.2*spectrum3+ normal(0.0, 1.0, len(t)) from numpy.linalg import lstsq Nparam = 3 A=zeros((len(t), Nparam),float) #helix A[:,0]=spectrum1 #beta A[:,1]=spectrum2 #coil A[:,2]=spectrum3 (p, residuals, rank, s) = lstsq(A,y) #A=p*A #fit = A[:,0]+A[:,1]#+A[:,2] #plot (t, y) #plot (t, fit) ------------------------------------------------------------------------ _______________________________________________ SciPy-user mailing list [hidden email] http://projects.scipy.org/mailman/listinfo/scipy-user ``` ```Hi, This works for me on Linux x86_64, Python 2.5 and '1.1.0.dev5133'. What are you using and what is the actual error message? Bruce _______________________________________________ SciPy-user mailing list [hidden email] http://projects.scipy.org/mailman/listinfo/scipy-user ``` Hi Bruce, I have a Vista PC (Intel Core2Duo) and Python 2.5 installed. I do not get any error message, it just hangs up, uses 50% of CPU and does not stop again. Sorry, but I am not sure what you mean by '1.1.0.dev5133'? Thanks, Gregor _______________________________________________ SciPy-user mailing list [hidden email] http://projects.scipy.org/mailman/listinfo/scipy-user