how to differentiate and plot of this function
조회 수: 3(최근 30일)
표시 이전 댓글
k1= @(x) sqrt(1-x^2);
k2=@(x) sqrt(2-x^2);
k3=@(x) sqrt(3-x^2);
k4=@(x) sqrt(4-x^2);
r1=@(x) (k1-k2)/(k1+k2);
r2=@(x) (k3-k4)/(k3+k4);
r3= @(x) (k2-k3)/(k2+k3);
y=@(x,d2,d3) -2*atan(1i*(1-r1)/(1+r1))*exp((1-r2*k1*d2)/(1+r2*km*d2))--2*atan(1i*(1-r3)/(1+r3))*exp((1-k2*d3)/(1+r4*k2*d3));
how to calculate dy/dx dy/dd2 and dy/dd3
plot d2 vs dy/dd2/dy/dd3
variation of d2 from 1 to 100;
y is multivariable depending upon d2,d3 x
댓글 수: 1
답변(1개)
Hiro
2022년 1월 25일
편집: Hiro
2022년 1월 25일
Why don't you use symbolic math expressions as follows?
Please run the script below:
syms k1(x) k2(x) k3(x) k4(x) r1(x) r2(x) r3(x) y(x,d2,d3)
k1 = sqrt(1-x^2)
k2 = sqrt(2-x^2)
k3 = sqrt(3-x^2)
k4 = sqrt(4-x^2)
r1 = (k1-k1)/(k1+k2)
r2 = (k3-k4)/(k3+k4)
r3 = (k2-k3)/(k2+k3)
Note that the first term (atan) does not work due to its singularity and you've got some typos in the expression and I corrected as follows:
y = -2*atan((1-r1)/(1+r1)) *exp((1-r2*k1*d2)/(1+r2*k1*d2))-2*atan(1i*(1-r3)/(1+r3))*exp((1-k2*d3)/(1+r3*k2*d3))
dydx = diff(y,x)
dydd3 = diff(y,d2)
dydd4 = diff(y,d3)
댓글 수: 2
Hiro
2022년 1월 25일
I don't think what you want to do is solve anything. I suppose you want to derive the partial derivatives.
Iif you want to get the analytic forms of the derivatives, use Symbolic Math otherwise numerical derivative would be a good fit.
The easiest way to use numerical derivative is use "approximation" such as numerical derivatives - you can chop the variables into small intervals and perform the calculations as shown in the document.
참고 항목
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!