Error in symengine for symbolic integration
12 visualizaciones (últimos 30 días)
Mostrar comentarios más antiguos
vahid s
el 18 de Ag. de 2021
Comentada: vahid s
el 20 de Ag. de 2021
I want to calculate a symbolic integration like below:
syms z
hc=2.5e-9;
hp=1e-9;
e31=-2.2;
z1=z-hc-(hp/2);
z2=z+hc+(hp/2);
B31_1=double(int(e31*(pi/hp)*(sin(pi*z2/hp))*(z^1),'z',-hc-hp,-hc)+int(e31*(pi/hp)*(sin(pi*z1/hp))*(z^1),'z',hc,hc+hp));
But I get this error:
Error using symengine
Out of memory.
Error in sym/int (line 167)
rSym = mupadmex('symobj::intdef',f.s,x.s,a.s,b.s,options);
Note: For z^0 there is no error, but when z has power, this error appears.
What is solution for this? Thanks in advance.
4 comentarios
Walter Roberson
el 19 de Ag. de 2021
Editada: Walter Roberson
el 19 de Ag. de 2021
On my system, in R2020a, it does not even use as much as 1 gigabyte between MATLAB itself and the MuPAD process to do the integration. No hint of a problem at all. MacOS.
Respuesta aceptada
Wan Ji
el 19 de Ag. de 2021
This is a bug in matlab. A good way to avoid this bug is just to predefine symbols rather than use constants in the symbolic process. When symbolic formula is derived, use subs and eval function to obtain the final results.
syms z hc hp e31
z1=z-hc-(hp/2);
z2=z+hc+(hp/2);
p = e31*(pi/hp)*(sin(pi*z2/hp))*z^1;
q = e31*(pi/hp)*(sin(pi*z1/hp))*z^1;
B31_1 = int(p,z,-hc-hp,-hc)+int(q,z,hc,hc+hp)
B31_1_val = eval(subs(B31_1,[hc,hp,e31],[2.5e-9, 1e-9, -2.2]))
The result in this
B31_1 =
(4*e31*hp)/pi
B31_1_val =
-2.801126998417358e-09
Since you observed this bug, I suggest you report it to MATHWORKS. You will be really appreciated. ovo
Más respuestas (0)
Ver también
Categorías
Más información sobre Calculus en Help Center y File Exchange.
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!