Error in multolying a number and function handle

2025 2 5
1 个回答
更新时间：2025 2 5
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0 个投票

I appreciate if you suggest sth to solve this problem
clear
clc
ro=7800; %%%% density of workpiece in kg/m3
k=14; %%% thermal conductivity of workpiece W/mK
Cp=460; %%%% specific heat capacity of workpiece in J/Kg.k
K=9.2e-6; %%% thermal expansion coefficient in (1/k)
E=114e3; %%%% Young Modulus
nu=0.33; %%% Poisson ratio
eta=0.9; %%%% percentage of total shear energy converted to enthalpy
a=k/(ro*Cp); %% thermal diffusivity (m2/s)
kt=110; %%%%%%% thermal conductivity of workpiece W/mK
rot=15600; %%%% density of tool in kg/m3
Cpt=280; %%% specific heat capacity of tool in J/Kg.k
%%%%%%%%%%%%%
t1=1e-3; % cutting thickness in m
alfa=0; %% rake angle in deg
l=@(x) t1./sind(x(1)); %% leght of shear plane in m
V=1; %% cutting velocity in m/s
Vsh=@(x) V*cosd(alfa)./cosd(x(1)-alfa);
EpilonAB=@(x) (1/(2*sqrt(3)))*cosd(alfa)./(cosd(x(1)-alfa).*sind(x(1)));
EpilondotAB=@(x) (1/sqrt(3))*x(2)*Vsh(x)./l(x);
Rt= ro*Cp*V*t1/k;
tanfi=@(x) tand(x(1));
if Rt*tanfi(x) <10
bettaa=@(x) 0.5-(0.35*log10(Rt*tanfi(x)));
else
bettaa=@(x) 0.3-(0.15*log10(Rt*tanfi(x)));
end
I recive following error for the line including if
Unrecognized function or variable 'x'.
Error in tamrinfunction (line 40)
if Rt*tanfi(x) <10

5 个评论
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John D'Errico
John D'Errico 2025-2-5
What is your problem? What is the rest of your question?
However, when I am mutilpying a number to...
Stephen23
Stephen23 2025-2-5
"I recive following error for the line including if "
What do you expect the value of x to be on that line?
Reza
Reza 2025-2-5

It should be x(1) belonging to the matrix x=[x(1) x(2) x(3)] that will be defined later while optimizing by particleswarm

Torsten
Torsten 2025-2-5
Then define
bettaa=@(x) (0.5-(0.35*log10(Rt*tanfi(x)))).*(Rt*tanfi(x) <10) + (0.3-(0.15*log10(Rt*tanfi(x)))).*(Rt*tanfi(x) >=10);
If it's getting even more complicated, don't use function handles. Write a function with input x where you compute the results needed.
Reza
Reza 2025-2-5

Thank you. I’ll go forward to check if it works with function instead of function handle

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回答（1 个）

Walter Roberson
Walter Roberson 2025-2-5

0 个投票

tanfi=@(x) tand(x(1));
Up to this point, you are creating function handles -- pieces of code that do not take action directly, but can be passed parameters in order to execute.
if Rt*tanfi(x) <10
Here you are trying to invoke tanfi() on a parameter, x. That is a problem because x is not defined.
There are two possibilities here:
  1. That you actually have some specific parameter, x, that you are trying to evaluate those statements over; OR
  2. That you are trying to define conditional logic, creating a bettaa function handle that uses 0.5 or 0.3 depending on the results of Rt*tanfi(x) <10
If you are trying to create a conditional function handle, you need to do something like
bettaa = @(x) (Rt.*tanfi(x) < 10).*(0.5-(0.35*log10(Rt*tanfi(x)))) + (Rt.*tanfi(x) >= 10).*(0.3-(0.15*log10(Rt*tanfi(x))))

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2025-2-5

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