how solve nonlinear equations ?

how to solve nonlinear equations ?
these 9 equations in 3 unknown but nonlinear
31.65951=sqrt((20460991.052399-x)^2+(11012393.207537-y)^2+(13140061.841029-z)^2)-sqrt((20462649.31-x)^2+(11012196.356-y)^2+(13137623.266-z)^2) 243.75898=sqrt((1704791.07688-x)^2+(20550181.098118-y)^2+(16863812.406607-z)^2)-sqrt((1706135.95-x)^2+(20548561.881-y)^2+(16865760.323-z)^2) -349.85327=sqrt((18327975.818007-x)^2+(1722639.77547-y)^2+(18786981.252914-z)^2)-sqrt((18326680.829-x)^2+(1720514.194-y)^2+(18788376.839-z)^2) -575.16382=sqrt((12050174.649623-x)^2+(-9980816.456693-y)^2+(21382458.132242-z)^2)-sqrt((12049062.298-x)^2+(-9983309.044-y)^2+(21381885.534-z)^2) 441.83588=sqrt((6415962.553149-x)^2+(15826350.755284-y)^2+(20754833.300093-z)^2)-sqrt((6418526.123-x)^2+(15826408.315-y)^2+(20754019.037-z)^2) -255.03605=sqrt((18966834.575125-x)^2+(6395897.26812-y)^2+(17720969.794907-z)^2)-sqrt((18965851.475-x)^2+(6393896.947-y)^2+(17722730.048-z)^2) 258.29132=sqrt((26283508.487939-x)^2+(-1051136.220342-y)^2+(4730820.234619-z)^2)-sqrt((26282933.567-x)^2+(-1051377.055-y)^2+(4733941.445-z)^2) -550.04848=sqrt((15456741.418182-x)^2+(19573966.047127-y)^2+(-9158923.170409-z)^2)-sqrt((15456435.97-x)^2+(19572808.522-y)^2+(-9161842.101-z)^2) 549.43288=sqrt((25702282.7043-x)^2+(2962424.062583-y)^2+(-6373870.064627-z)^2)-sqrt((25703029.058-x)^2+(2962107.626-y)^2+(-6370839.228-z)^2) but when using solve function [x,y,z] = solve('sqrt((20460991.052399-x)^2+(11012393.207537-y)^2+(13140061.841029-z)^2)-sqrt((20462649.31-x)^2+(11012196.356-y)^2+(13137623.266-z)^2)=31.65951', 'sqrt((1704791.07688-x)^2+(20550181.098118-y)^2+(16863812.406607-z)^2)-sqrt((1706135.95-x)^2+(20548561.881-y)^2+(16865760.323-z)^2)=243.75898', 'sqrt((18327975.818007-x)^2+(1722639.77547-y)^2+(18786981.252914-z)^2)-sqrt((18326680.829-x)^2+(1720514.194-y)^2+(18788376.839-z)^2)=-349.85327', 'sqrt((12050174.649623-x)^2+(-9980816.456693-y)^2+(21382458.132242-z)^2)-sqrt((12049062.298-x)^2+(-9983309.044-y)^2+(21381885.534-z)^2)=-575.16382', 'sqrt((6415962.553149-x)^2+(15826350.755284-y)^2+(20754833.300093-z)^2)-sqrt((6418526.123-x)^2+(15826408.315-y)^2+(20754019.037-z)^2)=441.83588', 'sqrt((18966834.575125-x)^2+(6395897.26812-y)^2+(17720969.794907-z)^2)-sqrt((18965851.475-x)^2+(6393896.947-y)^2+(17722730.048-z)^2)=-255.03605', 'sqrt((26283508.487939-x)^2+(-1051136.220342-y)^2+(4730820.234619-z)^2)-sqrt((26282933.567-x)^2+(-1051377.055-y)^2+(4733941.445-z)^2)=258.29132', 'sqrt((15456741.418182-x)^2+(19573966.047127-y)^2+(-9158923.170409-z)^2)-sqrt((15456435.97-x)^2+(19572808.522-y)^2+(-9161842.101-z)^2)=-550.04848', 'sqrt((25702282.7043-x)^2+(2962424.062583-y)^2+(-6373870.064627-z)^2)-sqrt((25703029.058-x)^2+(2962107.626-y)^2+(-6370839.228-z)^2)=549.43288')
the solution was empty x = [ empty sym ] y = [] z = []
why???????????????????/

5 个评论

Can you send a .m file instead, very hard to read the code above. Do you have optimization toolbox?
Since it is an overdetermined system (more equations than variables) is it a least squars solution you need or what do you mean by solution?
i tried to solve it manually by linearized these equation using Taylor's series and then solve using least square X= inv(A'A) A' L but the results was wrong i see the probelm in manual solution is the linearization step and the large estimation process so i want to find x y z using software

请先登录,再进行评论。

 采纳的回答

Erik S.
Erik S. 2015-2-18

0 个投票

Look in the documentation for the function lsqnonlin
It can solve nonlinear least squares problems.

更多回答(0 个)

类别

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by