Error "First input argument must be a function handle." function used fzero Please help to resolve the issue. Thanks

Jai
2023 10 29
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回答已采纳
更新时间：2023 10 29
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LHS = n(1) * (hf_0(1) + dh_CH4 ) + n(2) * (hf_0(2) + dh_O2); % I holds a double
%function [T_ad] = usolver(dh_CH4,dh_O2,n,hf_0,dh_CO2,dh_H2O,epsilon)
n = [1,2,1,2];
hf_0 = [-74873 , 0, -39352, -241826];
f = @(x) (- n(3) * (hf_0(3) + dh_CO2(x)) - n(4) * (hf_0(4) + dh_H2O(x))) + LHS ; % dh_CO2 & dh_H2O are functions in x
fzero(f,1000)
Error using fzero>localFirstFcnEvalError
FZERO cannot continue because user-supplied function_handle ==> @(x)(-n(3)*(hf_0(3)+dh_CO2(x))-n(4)*(hf_0(4)+dh_H2O(x))) failed with the error below.
First input argument must be a function handle.

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 采纳的回答

Star Strider
Star Strider 2023-10-29
Ran in:

1 个投票

Ran in:
The assignment statements are out-of-order (so ‘n’ and ‘hf_0’ do not yet exist when they are assigned in ‘LHS’) and two functons and two variable values are missing.
Supply the correct functions and values values and it should actually produce a useful result —
%function [T_ad] = usolver(dh_CH4,dh_O2,n,hf_0,dh_CO2,dh_H2O,epsilon)
dh_CO2 = @(x) sin(x);
dh_H2O = @(x) cos(x);
dh_CH4 = 1/42;
dh_O2 = 1/42^2;
n = [1,2,1,2];
hf_0 = [-74873 , 0, -39352, -241826];
LHS = n(1) * (hf_0(1) + dh_CH4 ) + n(2) * (hf_0(2) + dh_O2); % I holds a double
f = @(x) (- n(3) * (hf_0(3) + dh_CO2(x)) - n(4) * (hf_0(4) + dh_H2O(x))) + LHS ; % dh_CO2 & dh_H2O are functions in x
fzero(f,1000)
Exiting fzero: aborting search for an interval containing a sign change because NaN or Inf function value encountered during search. (Function value at -Inf is NaN.) Check function or try again with a different starting value.
ans = NaN
.

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