I am using the matlab to solve a simple model in economics. But I came across an error
Function 'subsindex' is not defined for values of class 'struct'
when I run the last line of code.
omega=mkt_share(Par,w,Grid);
It appears wired to me as I call this function repeatedly in the code before reaching the last line, it works fine. Could anyone inform me how to solve the problem? Thanks!
I post the full code of my program as following
clear all
Par.theta = 1.5;
Par.gamma = 6;
Par.beta = 0.1;
Par.zeta = 15;
Par.n = 100;
Grid.q = sort( gprnd(1/Par.zeta,1/Par.zeta,1,Par.n,1));
Grid.q = Grid.q./Grid.q(1);
w0=0.0001;
We0=tot_mkt_share(Par,w0,Grid);
mkt_share=mkt_share(Par,w0,Grid);
w1=0.01;
We1=tot_mkt_share(Par,w1,Grid);
while(We0*We1>0)
if We0<0
w0=w0*0.5;
We0=tot_mkt_share(Par,w0,Grid);
end
if We1>0
w1=w1*1.5;
We1=tot_mkt_share(Par,w1,Grid);
end
end
iconv2=0;
tol2=0.0000001;
maxit2=1000;
it2=1;
while(iconv2==0 && it2<=maxit2)
w=(w0+w1)/2;
We=tot_mkt_share(Par,w,Grid);
if abs(We)<tol2
iconv2=1;
disp('wage has converged in')
it2
else
if We*We1>0
w1=w;
else
w0=w;
end
it2=it2+1;
end
end
if it2>=maxit2
disp('Warning: Zero profit condition not satisfied')
end
omega=mkt_share(Par,w,Grid);
The code for function mkt_share
function omega=mkt_share(Par,w0,Grid)
omega=w0;
for i=2:Par.n
rel_q=Grid.q(i);
fcn=#(omega) (rel_q)^(-Par.gamma)*(omega/w0)^(1-Par.beta*Par.gamma)*((1-
((1-w0)/Par.gamma+w0/Par.theta))/(1-
((1omega)/Par.gamma+omega/Par.theta)))^(Par.gamma-1)-1;
omega_i=fsolve(fcn,w0);
omega=[omega',omega_i]';
end
The code for function tot_mkt_share, which calls function mkt_share
function tot_mkt_share=tot_mkt_share(Par,w0,Grid)
tot_mkt_share=sum(mkt_share(Par,w0,Grid))-1;
When you do:
mkt_share=mkt_share(Par,w0,Grid);
you create a variable with the same name as the function. From this point on, the function is no longer accessible, it is shadowed. The last line attempts to index into this variable, rather than call the function as you intend, because the function is shadowed.
Related
I want to find the Minimum of a function using
[x,fval] = fminsearch(#(param) esm6(param,identi),result(k,1:end-1),options)
now for each Iteration step i want some values that the function 'esm6' calculates to be saved in an Array. I tried the following:
In the first line of the function i wrote
identi.sim.i_optiIter = identi.sim.i_optiIter + 1;
to have an iteration-variable counting the iteration steps of fminsearch. And later to catch the values that I need I used
identi.sim.guete_werte.gew(identi.sim.i_optiIter,:,:) = y_sim;
identi.sim.guete_werte.ungew(identi.sim.i_optiIter,:,:) = y_sim_ungew;
and to make sure that I use the new values of the identi-struct for the next function call, I wrote this at the end of the function:
assignin('base','identi',identi);
Now unfortunatly it doesn't do what I wanted it to do. Can anyone help me with this?
EDIT:
I made another attempt on it, using an Output function. I extendend my Options like this:
options = optimset('Display','iter','MaxIter',3,'OutputFcn',#outfun);
But now the Problem is that i cannot figure out where to put this outfun. The outfun Looks like this:
function stop = outfun(x,optimvalues,state,iteration,y_sim,y_sim_ungew)
stop = false;
if state == 'iter'
guete_werte.gew(iteration,:,:) = y_sim;
guete_werte.ungew(iteration,:,:) = y_sim_ungew;
end
end
Now the Problem with it is, that i can not put it in the file, where i call the fminsearch, because that is a script. If i put the outputfunction into a separate .m-function file, it is not able to Access the variables of the esm6 function. And if I add it to the esm6-function file, matlab can't find the function and says
??? Error using ==> feval Undefined function or method 'outfun' for
input arguments of type 'struct'.
I have a class with a scheduler function that is supposed to insert characters into a cell array:
classdef timeline < handle
properties
schedule
i
%other properties
end
methods
%other functions
function t = timeline()
%other initializations
t.schedule = cell(1,738);
t.i = 1;
end
function scheduler(t, g, fT)
if nargin == 2
fT = t.i;
end
if strcmp(g,'science')
'science' % eclipse occurs after
for j = (fT+t.sTime+1) : (fT+t.sTime+1+t.eTime)
t.schedule{j} = 'e';
end
elseif strcmp(g,'pass')
'pass' % science occurs 2 hrs after end
for j = (fT) : (fT+t.pTime)
t.schedule{j} = 'p'
end
for j = (fT+t.pTime+121) : (fT+t.pTime+120+t.sTime)
t.schedule{j} = 's';
end
scheduler(t, 'science', fT+t.pTime+120);
end
end
end
end
In the command window, I define my object t = timeline() and a mode g = 'pass' and then call the scheduler, t.scheduler(t,g).
It doesn't change the schedule property. What's going on inside the if statements to write the schedule isn't the problem I am concerned with. I put outputs in each part of the if statement, and found that strcmp is returning false and skipping over the whole block. So, I added a break point in the scheduler function, and found that for some reason g is passed to the function as another timeline object instead of the string 'pass'. Why is this?
When you call a method for an object you can use dot notation or function notation. Dot notation means you call the method using the dot operator on the object instance. For example,
obj.methodName(args);
In function notation you pass the object instance variable as the first argument to the method. For example,
methodName(obj, args);
Both the above calls are equivalent and call the same method in the object. In both the calls MATLAB passes obj as input to the method. Note the absence of obj as an argument in the dot notation. In dot notation obj, is added as an input argument before your args. In your code you are mixing both of these options. So you got two obj arguments for your method.
Relevant documentation is at http://www.mathworks.com/help/matlab/matlab_oop/method-invocation.html
I have two functions, one is called from inside of another. I want certain parts of the first function to not execute when being called within the second function.
function vvec = vecVelocity(varargin);
%must be preceded with a 'syms var real' declaration where var is
%the parameter of your vector function
if nargin > 1 & nargin < 3
r = [sym(varargin(1:end))];
elseif nargin > 3
disp('too many inputs')
return
else r = [sym(varargin(1))];
end
if length(r) < 3
r = [r,0];
end
dr = diff(r);
uT = vecUnitTan(r);
speed = sqrt(sum(dr.^2));
v = speed*uT;
vvec = matlabFunction(v);
disp(['Simplified Symbolic Form: ' char(simplify(sym(vvec)))]);
I would like to suppress this last line disp(...) from appearing when I call this following second function from the command window
function speed = vecSpeed(r);
%must be preceded with a 'syms var real' declaration where var is
%the parameter of your vector function
v = sym(vecVelocity(r));
sp = sqrt(sum(v.^2));
speed = matlabFunction(sp);
disp(['Simplified Symbolic Form: ' char(simplify(sym(speed)))]);
At the moment, calling the vecSpeed function, causes a bunch of statements to be displayed from other preceding functions that are called from within the vecSpeed function (and some that are called from within the vecVelocity function), but I only want the disp(...) statement from the vecSpeed function to be called, not any of the others.
In the first function, you can put a block of codes in
if numel(dbstack) == 1
% Your code block
end
to prevent them to be executed unless the function is being called directly from Command Window.
Another way is to check for existence of some variables like debug_1, debug_2 etc.. which you can pass from the 2nd function when you call the 1st function.
I'm having some trouble with local functions within my code so I've pasted a simple example below:
function [avg,testvar] = test(x) %Warning
n = length(x);
avg = mymean(x,n);
end
function [a,testvar] = mymean(v,n)
a = sum(v)/n;
testvar=123;
end
One can probably see what I'm attempting; to pass testvar out of the local functions. However Matlab returns the warning:
"The function return value 'testvar' might be unset"
with respect to the line I've commented "%Warning".
What's the best way of getting around this?
You need to specify the value of the second output of test(). Otherwise how can MATLAB know what its value is supposed to be? It doesn't know the second output of mymean() should be routed to the second output of test(). Perhaps this will solve your problem.
function [avg,testvar] = test(x) %Warning
n = length(x);
[avg, testvar] = mymean(x,n);
end
function [a,testvar] = mymean(v,n)
a = sum(v)/n;
testvar=123;
end
The variables between brackets after function are the output variables.
In your first function, you did not assign any value to testvar hence the warning. If you add testvar = 123; in the first function, the warning goes away. Or you can remove testvar from the output variables, leaving:
function avg = test(x)
I am trying to write a minimal function that can be called with a variable number of arguments but that will not throw a wrong number of arguments error if miscalled.
Here is where I start from :
function varargout=fname(varargin)
% FNAME
% Usage: output=fname(input)
% Arguments check
if(nargin~=1 || nargout~=1)
disp('Function fname requires one input argument');
disp('and one output argument');
disp('Try `help fname`');
varargout(1:nargout)={0};
return;
end
input=varargin{1};
output=input;
varargout(1)={output};
end
However this does not work as I would like it to. Is there a way to write a function that :
never throw a "wrong number of arguments" error (so that the rest of the execution can continue)
accepts variable number of input and output arguments and checks them inside the function
(maybe more tricky) if the number of input / output arguments is not correct, does not replace the value of the provided output arguments (so that any misplaced call does not erase the previous value of the output argument)
I am open to any suggestions / other methods.
Thank you for your help.
UPDATE: thanks to #Amro for his answer, I guess what I miss here is either a call by address of reference for Matlab functions or a way to interrupt a function without returning anything and without stopping the rest of the execution.
Here is one way to implement your function:
function varargout = fname(input,varargin)
%# FNAME
%# Usage: output=fname(input)
%%# INPUT
if nargin<1
varargout(1:nargout) = {[]};
warning('Not enough input arguments.'), return
end
if ~isempty(varargin)
warning('Too many input arguments.')
end
%%# YOUR CODE: manipulate input, and compute output
output = input;
%%# OUTPUT
varargout{1} = output;
if nargout>1
warning('Too many output arguments.')
varargout(2:nargout) = {[]};
end
end
Obviously you can customize the warning messages to your liking...
Also, if you want your function to simply print the message instead of issuing warnings, replace all WARNING calls with simple DISP function calls.
Examples of function call:
fname()
fname(1)
fname(1,2)
x = fname()
x = fname(1)
x = fname(1,2)
[x,y] = fname()
[x,y] = fname(1)
[x,y] = fname(1,2)
The above calls execute as expected (showing warning messages when applicable). One caveat though, in the last three calls, if the variable y already existed in the workspace prior to the calls, it would be overwritten by the empty value y=[] in each...
If I understand your question correctly, then the answer is no. If a caller calls a function like this:
[a, b, c] = fname('foo');
then fname is required to return (at least) three outputs. There's no way to tell MATLAB that it should leave b and c alone if fname only returns one output.