Mercurial > hg > ltpda
comparison m-toolbox/test/straight_line_fit/lin_vs_nonlin.m @ 0:f0afece42f48
Import.
| author | Daniele Nicolodi <nicolodi@science.unitn.it> |
|---|---|
| date | Wed, 23 Nov 2011 19:22:13 +0100 |
| parents | |
| children |
comparison
equal
deleted
inserted
replaced
| -1:000000000000 | 0:f0afece42f48 |
|---|---|
| 1 mc | |
| 2 | |
| 3 a = 2; | |
| 4 b = 3; | |
| 5 x = -1:0.01:1; | |
| 6 xa = ao(plist('dtype', 'cdata', 'yvals', x)); | |
| 7 | |
| 8 n = 1*randn(size(x)); | |
| 9 sn = 2; | |
| 10 na = sn.*ao(plist('dtype', 'cdata', 'yvals', n)); | |
| 11 | |
| 12 y0 = a.*(xa + b).^3; | |
| 13 ya = y0 + na; | |
| 14 | |
| 15 %% linearisation | |
| 16 | |
| 17 | |
| 18 % ylin = dyda.*da + dydb.*db + y0; | |
| 19 | |
| 20 da = 0.2; | |
| 21 db = -0.3; | |
| 22 ag = a+da; | |
| 23 bg = b+db; | |
| 24 y0 = ag.*(xa + bg).^3; | |
| 25 | |
| 26 dyda = (xa+bg).^3; | |
| 27 dydb = ag.*(xa+bg).^2; | |
| 28 | |
| 29 tgtData = ya-y0; | |
| 30 fitData = lscov(dyda, dydb, tgtData); | |
| 31 | |
| 32 dfit = fitData - tgtData; | |
| 33 iplot(dfit) | |
| 34 iplot(hist(dfit)) | |
| 35 | |
| 36 params = find(fitData.procinfo, 'P') | |
| 37 af = ag + params(1) | |
| 38 bf = bg + params(2) | |
| 39 | |
| 40 errs = find(fitData.procinfo, 'STD'); | |
| 41 | |
| 42 afe = 100*errs(1)./af | |
| 43 bfe = 100*errs(2)./bf | |
| 44 | |
| 45 %% Non-linear fit | |
| 46 | |
| 47 xy = ao(plist('xvals', x, 'yvals', ya.y)); | |
| 48 pl = plist('Function', 'P(1).*(Xdata + P(2)).^3', 'P0', [ag bg]); | |
| 49 nlfit = curvefit(xy, pl); | |
| 50 | |
| 51 | |
| 52 |