using fsolve to solve non-linear equations in matlab
I'm trying to solve this system equations in matlab
syms y z i
x=[29.6,29.4,34.4,35.1,34.3,36.1,31.6,32.9,31.5,28.3,37.1,28.4,27.3,33.1,31.3,33.1]
n = 16
eqns = sym(zeros(1, 2 * n));
for i = 1:n
a = 0;
for j = 1:i
a = a + exp(-((x(j) - y) / z));
end
a = i/z - a/z;
eqns(i) = a == 0;
end
for i = 1:n
a = 0;
for j = 1:i
a = a + ((x(j) - y)/z^2) - ((x(i) - y)/z^2) * exp((-x(j) + y)/z);
end
a = -i/z + a;
eqns(i + 16) = a == 0;
end
eqns
solve(eqns, [y, z])
But it seems solve can't solve this one.
Warning: Cannot find explicit solution.
> In solve (line 316)
In xx (line 24)
I tried to use fslove but by follow the tutorial at https://www.mathworks.com/help/optim/ug/fsolve.html?s_tid=gn_loc_drop
but when I tried to enter
function F = root2d(x)
F(1) = exp(-exp(-(x(1)+x(2)))) - x(2)*(1+x(1)^2);
F(2) = x(1)*cos(x(2)) + x(2)*sin(x(1)) - 0.5;
matlab throw error.
Can someone please help me?
Thank you.
P/S: Can this problem be solved with singular?I'm trying to solve this system equations in matlab
systems-of-equations matlab singular-cas
asked Mar 8 '17 at 3:05
Lan Anh Nguyễn
11
add a comment |
I'm trying to solve this system equations in matlab
syms y z i
x=[29.6,29.4,34.4,35.1,34.3,36.1,31.6,32.9,31.5,28.3,37.1,28.4,27.3,33.1,31.3,33.1]
n = 16
eqns = sym(zeros(1, 2 * n));
for i = 1:n
a = 0;
for j = 1:i
a = a + exp(-((x(j) - y) / z));
end
a = i/z - a/z;
eqns(i) = a == 0;
end
for i = 1:n
a = 0;
for j = 1:i
a = a + ((x(j) - y)/z^2) - ((x(i) - y)/z^2) * exp((-x(j) + y)/z);
end
a = -i/z + a;
eqns(i + 16) = a == 0;
end
eqns
solve(eqns, [y, z])
But it seems solve can't solve this one.
Warning: Cannot find explicit solution.
> In solve (line 316)
In xx (line 24)
I tried to use fslove but by follow the tutorial at https://www.mathworks.com/help/optim/ug/fsolve.html?s_tid=gn_loc_drop
but when I tried to enter
function F = root2d(x)
F(1) = exp(-exp(-(x(1)+x(2)))) - x(2)*(1+x(1)^2);
F(2) = x(1)*cos(x(2)) + x(2)*sin(x(1)) - 0.5;
matlab throw error.
Can someone please help me?
Thank you.
P/S: Can this problem be solved with singular?I'm trying to solve this system equations in matlab
systems-of-equations matlab singular-cas
asked Mar 8 '17 at 3:05
Lan Anh Nguyễn
11
Yourfsolvecode doesn't match the system of 32 equations you're trying to solve symbolically. It's not clear what you're trying to do. I'm also not sure why you're usingias a symbolic variable and the re-defining it in yourforloops.
– horchler
Mar 8 '17 at 19:59
add a comment |
I'm trying to solve this system equations in matlab
syms y z i
x=[29.6,29.4,34.4,35.1,34.3,36.1,31.6,32.9,31.5,28.3,37.1,28.4,27.3,33.1,31.3,33.1]
n = 16
eqns = sym(zeros(1, 2 * n));
for i = 1:n
a = 0;
for j = 1:i
a = a + exp(-((x(j) - y) / z));
end
a = i/z - a/z;
eqns(i) = a == 0;
end
for i = 1:n
a = 0;
for j = 1:i
a = a + ((x(j) - y)/z^2) - ((x(i) - y)/z^2) * exp((-x(j) + y)/z);
end
a = -i/z + a;
eqns(i + 16) = a == 0;
end
eqns
solve(eqns, [y, z])
But it seems solve can't solve this one.
Warning: Cannot find explicit solution.
> In solve (line 316)
In xx (line 24)
I tried to use fslove but by follow the tutorial at https://www.mathworks.com/help/optim/ug/fsolve.html?s_tid=gn_loc_drop
but when I tried to enter
function F = root2d(x)
F(1) = exp(-exp(-(x(1)+x(2)))) - x(2)*(1+x(1)^2);
F(2) = x(1)*cos(x(2)) + x(2)*sin(x(1)) - 0.5;
matlab throw error.
Can someone please help me?
Thank you.
P/S: Can this problem be solved with singular?I'm trying to solve this system equations in matlab
systems-of-equations matlab singular-cas
asked Mar 8 '17 at 3:05
Lan Anh Nguyễn
11
I'm trying to solve this system equations in matlab
syms y z i
x=[29.6,29.4,34.4,35.1,34.3,36.1,31.6,32.9,31.5,28.3,37.1,28.4,27.3,33.1,31.3,33.1]
n = 16
eqns = sym(zeros(1, 2 * n));
for i = 1:n
a = 0;
for j = 1:i
a = a + exp(-((x(j) - y) / z));
end
a = i/z - a/z;
eqns(i) = a == 0;
end
for i = 1:n
a = 0;
for j = 1:i
a = a + ((x(j) - y)/z^2) - ((x(i) - y)/z^2) * exp((-x(j) + y)/z);
end
a = -i/z + a;
eqns(i + 16) = a == 0;
end
eqns
solve(eqns, [y, z])
But it seems solve can't solve this one.
Warning: Cannot find explicit solution.
> In solve (line 316)
In xx (line 24)
I tried to use fslove but by follow the tutorial at https://www.mathworks.com/help/optim/ug/fsolve.html?s_tid=gn_loc_drop
but when I tried to enter
function F = root2d(x)
F(1) = exp(-exp(-(x(1)+x(2)))) - x(2)*(1+x(1)^2);
F(2) = x(1)*cos(x(2)) + x(2)*sin(x(1)) - 0.5;
matlab throw error.
Can someone please help me?
Thank you.
P/S: Can this problem be solved with singular?I'm trying to solve this system equations in matlab
systems-of-equations matlab singular-cas
systems-of-equations matlab singular-cas
asked Mar 8 '17 at 3:05
Lan Anh Nguyễn
11
asked Mar 8 '17 at 3:05
Lan Anh Nguyễn
11
asked Mar 8 '17 at 3:05
Lan Anh Nguyễn
11
asked Mar 8 '17 at 3:05
Lan Anh Nguyễn
11
asked Mar 8 '17 at 3:05
Lan Anh Nguyễn
11
11
Yourfsolvecode doesn't match the system of 32 equations you're trying to solve symbolically. It's not clear what you're trying to do. I'm also not sure why you're usingias a symbolic variable and the re-defining it in yourforloops.
– horchler
Mar 8 '17 at 19:59
add a comment |
Yourfsolvecode doesn't match the system of 32 equations you're trying to solve symbolically. It's not clear what you're trying to do. I'm also not sure why you're usingias a symbolic variable and the re-defining it in yourforloops.
– horchler
Mar 8 '17 at 19:59
Your
fsolve code doesn't match the system of 32 equations you're trying to solve symbolically. It's not clear what you're trying to do. I'm also not sure why you're using i as a symbolic variable and the re-defining it in your for loops.– horchler
Mar 8 '17 at 19:59
Your
fsolve code doesn't match the system of 32 equations you're trying to solve symbolically. It's not clear what you're trying to do. I'm also not sure why you're using i as a symbolic variable and the re-defining it in your for loops.– horchler
Mar 8 '17 at 19:59
add a comment |
1 Answer
1
active
oldest
votes
It's not clear what the problem is without being given the error, but:
F=@(x) [exp(-exp(-(x(1)+x(2)))) - x(2)*(1+x(1)^2);x(1)*cos(x(2)) + x(2)*sin(x(1)) - 0.5];
x0=[1;1];
fsolve(F,x0)
worked for me. You can do this using "function F = ..." syntax, but then you need to write @F in the call to fsolve.
answered Mar 8 '17 at 3:36
Ian
67.3k25386
add a comment |
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It's not clear what the problem is without being given the error, but:
F=@(x) [exp(-exp(-(x(1)+x(2)))) - x(2)*(1+x(1)^2);x(1)*cos(x(2)) + x(2)*sin(x(1)) - 0.5];
x0=[1;1];
fsolve(F,x0)
worked for me. You can do this using "function F = ..." syntax, but then you need to write @F in the call to fsolve.
answered Mar 8 '17 at 3:36
Ian
67.3k25386
add a comment |
It's not clear what the problem is without being given the error, but:
F=@(x) [exp(-exp(-(x(1)+x(2)))) - x(2)*(1+x(1)^2);x(1)*cos(x(2)) + x(2)*sin(x(1)) - 0.5];
x0=[1;1];
fsolve(F,x0)
worked for me. You can do this using "function F = ..." syntax, but then you need to write @F in the call to fsolve.
answered Mar 8 '17 at 3:36
Ian
67.3k25386
add a comment |
It's not clear what the problem is without being given the error, but:
F=@(x) [exp(-exp(-(x(1)+x(2)))) - x(2)*(1+x(1)^2);x(1)*cos(x(2)) + x(2)*sin(x(1)) - 0.5];
x0=[1;1];
fsolve(F,x0)
worked for me. You can do this using "function F = ..." syntax, but then you need to write @F in the call to fsolve.
answered Mar 8 '17 at 3:36
Ian
67.3k25386
It's not clear what the problem is without being given the error, but:
F=@(x) [exp(-exp(-(x(1)+x(2)))) - x(2)*(1+x(1)^2);x(1)*cos(x(2)) + x(2)*sin(x(1)) - 0.5];
x0=[1;1];
fsolve(F,x0)
worked for me. You can do this using "function F = ..." syntax, but then you need to write @F in the call to fsolve.
answered Mar 8 '17 at 3:36
Ian
67.3k25386
answered Mar 8 '17 at 3:36
Ian
67.3k25386
answered Mar 8 '17 at 3:36
Ian
67.3k25386
answered Mar 8 '17 at 3:36
Ian
67.3k25386
67.3k25386
add a comment |
add a comment |
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Your
fsolvecode doesn't match the system of 32 equations you're trying to solve symbolically. It's not clear what you're trying to do. I'm also not sure why you're usingias a symbolic variable and the re-defining it in yourforloops.– horchler
Mar 8 '17 at 19:59