Error in plotting - indices not compatible
Afficher commentaires plus anciens
I have the following code -
syms y t g
f1 = -2*g*(t.^3 +t.^2)/((1 - y).^(1-2*g)) + 2*g*(3-t)*(3 - t.^2)^2./(((2 - t).^2).*y.^(1-2*g)) + (8*g*(t+1))./(y.^(1- 2*g)) - 2*g*(3-t)*(3 - 2*t).^2./(((2 - t).^2).*(1 - y).^(1-2*g));
[N1,D1] = numden(f1);
f2 = t - (((y.^(2*g))*(2/3) - (((1-y).^(2*g)).*((3 - 2*t)./(3*(2-t)))))./((y.^(2*g)).*(((3-t.^2))./(3*(2-t))) - ((1-y).^(2*g)).*(t/3)));
[N2,D2] = numden(f2);
tsol = solve(N2==0,t,'MaxDegree',3);
N1_subs_tsol1 = subs(N1,t,tsol(1));
N1_subs_tsol2 = subs(N1,t,tsol(2));
N1_subs_tsol3 = subs(N1,t,tsol(3));
G = 0.01:0.001:0.12;
soly1(1) = vpasolve(subs(N1_subs_tsol1/(y*(1-y)^(2*g)),g,G(1))==0,y);
soly2(1) = vpasolve(subs(N1_subs_tsol2/y/(-2*g),g,G(1))==0,y);
soly3(1) = vpasolve(subs(N1_subs_tsol3/y/(-2*g),g,G(1))==0,y);
for i = 2:numel(G)
soly1(i) = vpasolve(subs(N1_subs_tsol1/(y*(1-y)^(2*g)),g,G(i))==0,y,soly1(i-1));
soly2(i) = vpasolve(subs(N1_subs_tsol2/y/(-2*g),g,G(i))==0,y,soly2(i-1));
soly3(i) = vpasolve(subs(N1_subs_tsol3/y/(-2*g),g,G(i))==0,y,soly3(i-1));
end
solt1 = arrayfun(@(soly1,G)subs(tsol(1),[y,g],[soly1,G]),soly1,G);
solt2 = arrayfun(@(soly2,G)subs(tsol(2),[y,g],[soly2,G]),soly2,G);
solt3 = arrayfun(@(soly3,G)subs(tsol(3),[y,g],[soly3,G]),soly3,G);
hold on
p1 = plot(G,soly1,'r');
%plot(G,solt1,'r')
p2 = plot(G,soly2,'b');
%plot(G,solt2,'b')
p3 = plot(G,1./(1+(1/3).^(1./(1-2*G))),'g');
legend([p1,p2,p3],[" Slice 1","Slice 2","Slice 3"])
xlabel("g")
hold off
grid on
Why I am getting the following error -
Unable to perform assignment because the
indices on the left side are not compatible
with the size of the right side.
Error in sym/privsubsasgn (line 1200)
L_tilde2 = builtin('subsasgn',L_tilde,struct('type','()','subs',{varargin}),R_tilde);
Error in indexing (line 1031)
C = privsubsasgn(L,R,inds{:});
Please help @Torsten
Réponses (1)
vpasolve is returning empty (because it found no solution), so you cannot assign it to soly3(1)
>> vpasolve(subs(N1_subs_tsol3/y/(-2*g),g,G(1))==0,y)
ans =
Empty sym: 0-by-1
5 commentaires
Sabrina Garland
le 18 Sep 2023
Matt J
le 18 Sep 2023
You can rewrite the code along the following lines
tmp= vpasolve(subs(N1_subs_tsol3/y/(-2*g),g,G(1))==0,y);
if ~isempty(tmp)
soly3(1)=tmp;
else
Do something else
end
Dyuman Joshi
le 18 Sep 2023
Remove the index and store in a variable instead of storing in an element.
Sabrina Garland
le 19 Sep 2023
Matt J
le 19 Sep 2023
That's what my last comment shows.
Catégories
En savoir plus sur Number Theory dans Centre d'aide et File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!