ZinsLab.org

Steven D. Zins' Physics Projects

User Tools

Site Tools


b:slope_compensation

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Next revision
Previous revision
b:slope_compensation [2022/01/25 03:48]
sz created
b:slope_compensation [2022/01/25 17:41] (current)
sz
Line 2: Line 2:
  
 Miller compensates for the interferometer drift or slope over each page, ie 20 turns. Miller compensates for the interferometer drift or slope over each page, ie 20 turns.
-Advantage calculation are on single page.+Advantage calculation are on single page. see p214 
 + 
 +The purpose of this test is to find the 
 +effect of slope on the sin[ ] component in an interval of 2 Pi. 
 + 
 + 
 + 
 +=== FindFit Approach === 
 + 
 +See ApexMeansTest.nb 
 + 
 +Fourier analysis assumes that a signal repeats on some fixed cycle. If a signal does not do this, then FA cannot be used. At least without closing the cycle or the like. 
 + 
 +This program shows that when the "c" parameter is removed from the model expression, then the "a" parameter  (on Sin[]) increases wildly. But when the "c" is present, the "a" parameter matches the "a1" in the data(xy) generation code. 
 +This means that the linear term "c x" completely prevents the linear slope from affecting the true Sin[ ] component.  
 + 
 +also to find out how to structure data for FindFit  
 + "data" 
 + 
 +<code mathematica> 
 + 
 + 
 +Clear[x,y,x1]; 
 +imax=20; 
 +x2=Table[i/2.,{i,imax}]; 
 +Print[" ",x2]; 
 + 
 +a1=1.01; b1=25; c1=10; 
 +xy= Table[{x1/2.,a1 Sin[2 Pi .1 x1/2.]+ b1 + c1 x1/2.},{x1,imax}]; 
 +Print["xy  ",xy]; 
 + 
 +ff=FindFit[xy, Sin[2 Pi .1 x] + b + c  x,{a,b,c},x]; 
 +Print["angles ",Table[2 Pi .1 x1/2.,{x1,imax}]]; 
 +Print["ff  ",ff]; 
 + 
 +x  {0.5,1.,1.5,2.,2.5,3.,3.5,4.,4.5,5.,5.5,6.,6.5,7.,7.5,8.,8.5,9.,9.5,10.} 
 +xy  {{0.5,30.3121},{1.,35.5937},{1.5,40.8171},{2.,45.9606},{2.5,51.01},{3.,55.9606},{3.5,60.8171},{4.,65.5937},{4.5,70.3121},{5.,75.},{5.5,79.6879},{6.,84.4063},{6.5,89.1829},{7.,94.0394},{7.5,98.99},{8.,104.039},{8.5,109.183},{9.,114.406},{9.5,119.688},{10.,125.}} 
 +angles {0.314159,0.628319,0.942478,1.25664,1.5708,1.88496,2.19911,2.51327,2.82743,3.14159,3.45575,3.76991,4.08407,4.39823,4.71239,5.02655,5.34071,5.65487,5.96903,6.28319} 
 +ff  {a->1.01,b->25.,c->10.} 
 + 
 + 
 +</code> 
 + 
 + 
 +=== First approach. ===
  
 I could do the same over whole day: 24h * 60t/h = 1440 turns.  I could do the same over whole day: 24h * 60t/h = 1440 turns. 
Line 8: Line 52:
 This would cause a daily cycle in the interferometric sin component, albeit 1/1440 as large each day. This would cause a daily cycle in the interferometric sin component, albeit 1/1440 as large each day.
  
-Or even entire set of days in name-list.+Or even an entire set of days in name-list. 
 + 
 +Effect of slope on sin[ ] in interval 2 Pi.  
 + 
 + 
 + 
b/slope_compensation.1643100539.txt.gz · Last modified: 2022/01/25 03:48 by sz