I have a mex-function specialRationalMap_00001.mexw64, that can be called without problems
vm = specialRationalMap_00001(vm,amplitude);
If I am trying to use the function name and str2func
f_str = 'specialRationalMap_00001';
fz = str2func(strcat('#(vm,amplitude)', f_str));
vm = fz(vm,amplitude);
I got the error: "A map input and a (scalar) amplitude required", but I am using exactly this as input.
Dont forget to actually pass the input arguments. Either do
fz = str2func(strcat('#(vm,amplitude)', f_str, '(vm,amplitude)'));
But better, you can just do:
fz = str2func(f_str);
Related
This is the code I write in Matlab. As you can see, I have defined the symbolic variable tao. However, it still shows that undefined variable or functions. I didn't know where is wrong in the code.
The function is like this:
Ch = 0.8; H=0.6088;
syms t u s k tao
fsb= limit( symsum( (int( Ch*s^(1/2)*int((u-s)^(H-3/2)*u^(H-1/2),u,floor(t/tao)*tao,floor((t+tao)/tao)*tao),s,(k-1)*tao,k*tao ))^2,k,1,floor(t/tao)),tao,0) + ...
+limit( (int( Ch*s^(1/2)*int((u-s)^(H-3/2)*u^(H-1/2),u,s,floor((t+tao)/tao)*tao ),s,floor(t/tao)*tao,floor((t+tao)/tao)*tao) )^2,tao , 0);
fsb = matlabFunction(fsb);
sss=fsb(1);
I have tried change the path into the Matlab installed path, but it didn't work.
The fsb is a function defined by my self. It's a complicated function including integral and limit.
This is the information about the error:
undefined functions or variables 'tao'
symengine>#(t)limit(integral(#(s)sqrt(s).*integral(#(u)u.^(6.8e1./6.25e2).*1.0./(-s+u).^(5.57e2./6.25e2),s,tao.*floor((t+tao)./tao)).*(4.0./5.0),tao.*floor(t./tao),tao.*floor((t+tao)./tao)).^2,tao==0.0)+limit(symsum(integral(#(s)sqrt(s).*integral(#(u)u.^(6.8e1./6.25e2).*1.0./(-s+u).^(5.57e2./6.25e2),tao.*floor(t./tao),tao.*floor((t+tao)./tao)).*(4.0./5.0),tao.*(k-1.0),k.*tao).^2,k,1.0,floor(t./tao)),tao==0.0,Real)
I am a newbie of matlab and am trying to define a pretty complex function to plot it. The content of file is following:
function [res] = distribution (input)
a = factorial(30)
b = factorial(input) * factorial(30-input)
c = power(0.05, input)
d = power(0.95, 30-input)
a/b*c*d
end
in the file named distribution with .m extension. But when I run it error returns: "Error using distribution (line 4). Not enough input arguments."
I read through the "Getting Started" and find no solution. Does anyone have suggestions on this?
The name of the single argument to your function distribution(..), namely argument input, conflicts with the existing native input command of Matlab,
input: Prompt for user input.
...
x = input(prompt)
Try choosing a different name of this argument (in example below: foo), and also remember to return your result by assigning it to the return variable res:
function res = distribution (foo)
a = factorial(30);
b = factorial(foo) * factorial(30-foo);
c = power(0.05, foo);
d = power(0.95, 30-foo);
res = a/b*c*d; % <--- note, return parameter assignment
end
I called Matlab's genetic algorithm solver, ga, in the following way:
[theta,fval,exitflag] = ga(smmobj,26,[],[],[],[],LB,UB,[],[]);
where theta is a 26-by-1 column vector that needs to be optimized.
So in the main function, it goes like this:
clc
clear
global var1 var2...
load ('abcd.mat')
theta0=[1 2 3....];
LB=[26-by-1 row vector];
UB=[26-by-1 row vector];
[theta,fval,exitflag] = ga(smmobj,26,[],[],[],[],LB,UB,[],[]);
The fitness function, smmobj, is defined as:
function [obj]=smmobj(theta)
global var1 var2...
But when I run it, it always says:
Error using smmobj (line 4)
Not enough input arguments.
Error in SMMga (line 32)
[theta,fval,exitflag] = ga(smmobj,26,[],[],[],[],LB,UB,[],[]);
But I run the fitness function by itself, it works.
[theta,fval,exitflag] = ga(smmobj,26,[],[],[],[],LB,UB,[],[]);
will throw that error because you are essentially calling the function smmobj (with no parameters) instead of passing your ga function a function handle to your objective function. You do this using the # symbol so
[theta,fval,exitflag] = ga(#smmobj,26,[],[],[],[],LB,UB,[],[]);
Incidentally, I would recommend that you do not use global in order to pass the extra parameters of var1 and var2 to your objective function but rather use anonymous functions:
[theta,fval,exitflag] = ga(#(x)(smmobj(x,var1,var2)),26,[],[],[],[],LB,UB,[],[]);
and then change smmobj's definition to
function [obj]=smmobj(theta,var1,var2)
I created an anonymous function inside a script and I can't get MATLAB to run the fminsearch? Here's an what I have so far:
V=x(1);
f=x(2);
q=#(x) (pi.*D.*L)./(1000.*V.*f);
fminsearch(#q,x);
The variables D and L are defined, but MATLAB gives me the following error:
Error: File: Testing.m Line: 51 Column: 17
"q" was previously used as a variable, conflicting with its use here as the name of a function or command.
See "How MATLAB Recognizes Command Syntax" in the MATLAB documentation for details.
q is not mentioned before this command. What am I doing wrong?
Another thing that could solve my problem is to get my script to write a function file, but how to do that?
Remove the second #:
V=x(1);
f=x(2);
q=#(x) (pi.*D.*L)./(1000.*V.*f);
fminsearch(q,x);
q is a function handle. fminsearch expects a function handle. You can create a function handle out of a function using an # (e.g. #min), but you don't need to do that here.
You can also write the anonymous function inline with the search command:
V=x(1);
f=x(2);
fminsearch(#(x) (pi.*D.*L)./(1000.*V.*f),x);
UPDATE (credits to #wakjah)
For your code to do anything sensible, you should use the argument x of the anonymous function:
x0 = [initialV, initialF];
fminsearch(#(x) (pi.*D.*L)./(1000.*x(1).*x(2)), x0);
#function creates a function handle for an existing function.
q = #(x) whatever... creates a function handle called q.
But, you can't create a function handle for a function handle, only for a function.
See this:
>> fones = #ones
fones =
#ones
>> ffones = #fones
Error: "fones" was previously used as a
variable,
conflicting with its use here as the name
of a function or command.
See MATLAB Programming, "How MATLAB
Recognizes Function Calls That Use
Command Syntax" for details.
In Matlab, a function handle is a kind of a pointer to a function and is distinct from a function (unlike in some other languages where the a function identifier can be passed and stored as any other variable).
It's important to note that calling a function and a function handle results in the same behaviour. Except for the case where the identifier is used without any parentheses following it:
>> ones
ans =
1
>> fones
fones =
#ones
>> ones(2)
ans =
1 1
1 1
>> fones(2)
ans =
1 1
1 1
This is my function
function [mean,stdev] = stat(x)
n = length(x);
mean = sum(x)/n;
stdev = sqrt(sum((x-mean).^2/n));
and I called
[mean stdev] = stat([12.7 45.4 98.9 26.6 53/1])
??? Undefined function or method 'stat' for input arguments of type 'double'.
I also tried
mean,stdev = stat([12.7 45.4 98.9 26.6 53/1])
??? Input argument "x" is undefined.
Error in ==> mean at 30
y = sum(x,dim)/size(x,dim);
Both of them are wrong and I cannot figure out why.
Could you please help me =] Thanks a lot
Your function looks fine to me, therefore I assume that your Matlab "Current Directory" is not the same directory where your function lives.
Another reason might be that the file in which this function exists does not have the same as this function. In order for Matlab to know that this function exists, it has to live in a separate file called stat.m (note how file name is the same as the function name).