How do I multiply two functions handles?
4 views (last 30 days)
Show older comments
Tlotlo Oepeng
on 14 Jun 2022
Commented: Star Strider
on 14 Jun 2022
%%---------constants:
Gma_32 = 100
Gma = 210e-15
gamma_u = 500
gamma_c = 50
a = Gma_32/sqrt(2*gamma_u*Gma)
n = 4e10
c1 = -4
c2 = 2.05
c3 = 1
K = 10
%--------Function
%
% X = @(k) -4*n - a^2*n*sqrt(n) + 4*c1*k.^4 + (2*a*sqrt(n)-16*K^2 + 4*a*c1*c3*sqrt(n) + 8*n*c1*c2)*k.^2
% Sq = @(k) sqrt((-X(k) + sqrt(X(k).^2 + Y^2 ))/2)
% f = @(k) -2*k.^2 - 2*n - a*sqrt(n) + Sq(k)
% f2 = @(k) -2*k.^2 - 2*n - a*sqrt(n) - Sq(k)
%------------------------------Fns:
b_i = @(k) -4*c1*k*K
b_r = @(k) 2*k.^2 +2*n + a*sqrt(n)
c_i = @(k) ( 4*n*c2* - 2*(2*n + a*sqrt(n))*c1 + 2*a*sqrt(n)*c3 )*K*k
c_r = @(k) -(1 + c1^2)*k.^4 - (2*n -4*(1 + c1^2)*K^2 + sqrt(n)*c3*c1 + 2*n*c1*c2 )*k.^2
D_r = @(k) b_r(k).^2 - b_i(k).^2 -4*c_r(k)
D_i = @(k) 2*b_i(k).*b_r(k) - 4*c_i
f = @(k) -b_i(k) + sqrt( -D_r(k) + sqrt(D_i(k)^2 + D_r(k)^2))/4
%-------Grid:
k = -200:0.1:200
% %-------Plot
%
plot(k,f(k))
%plot(k,f2(k))
theres an error on line with function f, how do i multiply two functoin handles. or suggest a bwtter way of plotting this function.
1 Comment
Steven Lord
on 14 Jun 2022
FYI for the future, when you're asking for help with code that throws an error message or issues a warning message please include the full and exact text of the error or warning message in your original question. This information may help readers determine the cause of the error and how to correct it more quickly. Thanks.
Accepted Answer
Star Strider
on 14 Jun 2022
In the ‘D_i’ function, ‘c_i’ was originally missing its argument, and that threw the error.
Correcting that, and vectorising the exponentiations produces —
%%---------constants:
Gma_32 = 100;
Gma = 210e-15;
gamma_u = 500;
gamma_c = 50;
a = Gma_32/sqrt(2*gamma_u*Gma);
n = 4e10;
c1 = -4;
c2 = 2.05;
c3 = 1;
K = 10;
%--------Function
%
% X = @(k) -4*n - a^2*n*sqrt(n) + 4*c1*k.^4 + (2*a*sqrt(n)-16*K^2 + 4*a*c1*c3*sqrt(n) + 8*n*c1*c2)*k.^2
% Sq = @(k) sqrt((-X(k) + sqrt(X(k).^2 + Y^2 ))/2)
% f = @(k) -2*k.^2 - 2*n - a*sqrt(n) + Sq(k)
% f2 = @(k) -2*k.^2 - 2*n - a*sqrt(n) - Sq(k)
%------------------------------Fns:
b_i = @(k) -4*c1*k*K;
b_r = @(k) 2*k.^2 +2*n + a*sqrt(n);
c_i = @(k) ( 4*n*c2* - 2*(2*n + a*sqrt(n))*c1 + 2*a*sqrt(n)*c3 )*K*k;
c_r = @(k) -(1 + c1^2)*k.^4 - (2*n -4*(1 + c1^2)*K^2 + sqrt(n)*c3*c1 + 2*n*c1*c2 )*k.^2;
D_r = @(k) b_r(k).^2 - b_i(k).^2 -4*c_r(k);
D_i = @(k) 2*b_i(k).*b_r(k) - 4*c_i(k);
f = @(k) -b_i(k) + sqrt( -D_r(k) + sqrt(D_i(k).^2 + D_r(k).^2))/4;
%-------Grid:
k = -200:0.1:200;
% %-------Plot
%
plot(k,f(k))
%plot(k,f2(k))
.
0 Comments
More Answers (1)
See Also
Categories
Find more on Loops and Conditional Statements in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!