1stOpt 拟合得到的参数,在MATLAB里面绘制出来图形为什么不一样?
SharedModel;
Variable x,y(2);//y1,y2;
Parameter a=[-2,2],b=[-1,1],c=[-2,2],d=[-1,1];
Constant epsilon=0.3921,h0=6.3,R=125,Sf=0.04558,VR=1308.33;
ConstStr h1=h0*(1-epsilon),Delta_h=h0*epsilon,
L=sqrt(R*Delta_h-(Delta_h^2)/4),
z=Delta_h*x^2/(2*L^2)+h1/2,V1=VR*(1+Sf),Vx=h1*V1/(2*z),V0=h1*V1/h0,
delta_f=15+9.2*((h0-2*z)/h0)^0.11,
p1=(exp(2*b*(a*Vx-V0)*x/z^2))*(4/3*b*delta_f*Delta_h/((L^2)*z^3)*(V0-a*Vx)*x^3+delta_f*Delta_h*x^2/(z*L^2)+delta_f*(1-2*Delta_h/h0));
Function y1=p1;
y2=delta_f*Delta_h*x/(L^2)+2*d*(c*Vx-V0)*y1/z;
Data;
//x,y1,y2
1.25 66.16352201 32.45283019
2.5 99.87421384 34.96855346
3.75 86.28930818 41.00628931
5 80.75471698 25.91194969
6.25 76.72955975 21.88679245
7.5 67.67295597 18.36477987
8.75 60.62893082 1.257861635
10 56.60377358 -15.8490566
11.25 54.59119497 -28.42767296
12.5 53.58490566 -28.93081761
13.75 54.08805031 -33.96226415
15 48.55345912 -20.37735849
16.25 44.02515723 -10.81761006
17.5 45.03144654 -5.283018868
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MATLAB
clear;
h0=6.32;epsilon=0.304;R=125;VR=1046.67;Sf=0.03456;h1=h0*(1-epsilon);
Delta_h=h0-h1;L=sqrt(R*Delta_h-(Delta_h^2)/4);
x=0:0.01:L;b=0.0012;
z=Delta_h*x.^2/(2*L^2)+h1/2;
Vx=h1*VR*(1+Sf)./(2*z);V1=(1+Sf)*VR;V0=h1*V1/h0;
delta_f=10+9*(((h0-2*z)/h0).^0.06);
a=0.85;b=0.004;
p2=(exp(2*b*(a*Vx-V0).*x./z.^2)).*(4/3*b*delta_f*Delta_h./(L^2*z.^3).*(V0-a*Vx).*x.^3+delta_f*Delta_h.*x.^2./(L^2*z)+delta_f*(1-2*Delta_h/h0));
plot(x,p2)
c=0.68;d=0.014;
t2=delta_f*Delta_h.*x/(L^2)+2*d*(c*Vx-V0).*p2./z;
hold on
plot(x,t2)
![1stOpt 拟合的曲线为什么和MATLAB里面绘出来的不一样?]()
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![1stOpt 拟合的曲线为什么和MATLAB里面绘出来的不一样?-1]()
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![1stOpt 拟合的曲线为什么和MATLAB里面绘出来的不一样?-2]()
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