Evaluating polynomial functions to get integer as answer
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I am trying to evaluate:
syms x y
eq = (x^2 + y^3 == 31)
solve(eq)
eqs = [x^2 + y^3 == 31, x^2 == 31 - y^3]
S = solve(eq,[x y])
S.x and S.y still not 2 and 3
i am expecting to get as answer two integer: x=2 and y=3. How can i do it?
Thanks
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采纳的回答
Walter Roberson
2021-4-4
编辑:Walter Roberson
2021-4-4
syms x y integer
eq = (x^2 + y^3 == 31)
solx = solve(eq,x,'returnconditions',true)
soly = solve(solx.conditions)
X = subs(solx.x,y,soly)
Y = soly
Caution: this kind of process will not generally attempt to find more than one solution for solx.conditions. But you could
soly = solve(eq,y,'returnconditions',true)
solx = arrayfun(@solve, soly.conditions, 'uniform', 0)
X = solx{2}
Y = subs(soly.y(2), x, X)
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更多回答(1 个)
darova
2021-4-4
solve can be used for simple problems. Use fsolve or vpasolve to get numerical results
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Walter Roberson
2021-4-4
Not the point. The point is that solve() is having difficulty processing integer constraints in this case. fsolve and vpasolve have no chance of processing integer constraints.
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