How to modify the ND procedure to handle derivatives with respect to more than three independent variables for higher-dimensional PDEs, it is work for [x,t] i want it work for [x,y,z,t] ,
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alias(F=F(x, t), G=G(x, t))
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with(PDEtools):
undeclare(prime):
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ND := proc(F, G, U)
local v, w, f, g, a:
v := op(F):
if v[1] in U then w := -v[1] else w := v[1] end if:
if v[2] in U then w := w, -v[2] else w := w, v[2] end if:
f := op(0, F):
g := op(0, G):
a := diff(f(w)*g(v), U);
convert(subs([w]=~[v], a), diff)
end proc:
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ND(F, G, [x]);
ND(F, G, [t]);
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(4) |
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ND(F, F, [x]);
ND(F, F, [x, x]);
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#if i collect P1+P1+...+P7 it must get equation 26 in paper so i want define the up proc to open but is not for (3+1) dimesnion,
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Download define.mw
