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plotting a function from anothe .m file , please help

Asked by Tareq

Tareq (view profile)

on 11 Aug 2012

i am facing a problem plotting this function

objfun244.m

function f=objfun244(tp)
% The objective function: total cost per unit time if replacement interval is tp
% Assumption: The smallest time unit is week. 
% f: total cost per unit time
% tp: Length of the time interval in Weeks (preventive replacement interval)
global Cp Cf   % cost of preventive replacement and failure replacement, respectively
T =ceil(tp);
% f: total cost per unit time C_tp
f=(Cp+Cf*HT(T))/tp;
% % Test
% objfun244(4)

then on another .m file which is called plotting2.m here is the code i wrote

clear all;
clc;
t = i:1:12;
plot(t,objfun244(t));
grid on
xlabel('t')
ylabel('COST')

---------------------------------------

there is another function called H T , here is its code

function H=HT(T)
% The recursive function H(T)
% Calculate the Expected number of failures in (0,T], for Weibull
% Distribution
% Assumption: T's unit is week, the smallest time unit. 
% H: the Expected number of failures in (0,T] 
% T: length of the time interval in weeks (preventive replacement interval)
% T is a nonnegative integer: 0, 1, 2, 3, ...
global Al Be % Alpha and Beta for the Weibull distribution, respectively  % #####
global HT_vec HT_flag % Calculated H(T) values: HT_flag(T)=1 if it has been calculated
H=0;   % H(0)=0: initial value
if T<0.001
%     H=0;   % If T=0, H(T)=0;
elseif HT_flag(T)>0
    % If HT(T) has been calculated, used the saved value    
    H=HT_vec(T);  % Assign the value from HT_vec
else
    % Otehrwise, recursively calculate H(T)
    % i: time from 0 to T-1
      for i=0:(T-1)
          H=H+(1+HT(T-i-1))*(wblcdf(i+1,Al,Be)-wblcdf(i,Al,Be)); % #####
      end
      % Save the calculated H(T) value
      HT_vec(T)=H;
      HT_flag(T)=1;
  end

----------------------------------------------------

i got error : ??? Subscript indices must either be real positive integers or logicals.
Error in ==> HT at 20
elseif HT_flag(T)>0
Error in ==> objfun244 at 12
f=(Cp+Cf*HT(T))/tp;
Error in ==> plotting2 at 11
plot(t,objfun244(t));

-----------------------------

pleaseeee hellpppppp

0 Comments

Tareq

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1 Answer

Answer by Matt Fig

Matt Fig (view profile)

on 11 Aug 2012
Edited by Matt Fig

Matt Fig (view profile)

on 11 Aug 2012
Accepted answer

The problem is here:

clear all;
clc;
t = i:1:12;

Did you mean

t = 1:12;

10 Comments

Tareq

Tareq (view profile)

on 11 Aug 2012
function H=HT2(T)
% The recursive function H(T)
% Calculate the Expected number of failures in (0,T], for Weibull
% Distribution
% Assumption: T's unit is week, the smallest time unit. 
% H: the Expected number of failures in (0,T] 
% T: length of the time interval in weeks (preventive replacement interval)
% T is a nonnegative integer: 0, 1, 2, 3, ...
global Al Be % Alpha and Beta for the Weibull distribution, respectively  % #####
global HT_vec HT_flag % Calculated H(T) values: HT_flag(T)=1 if it has been calculated
T= 2:1:12;
H=0;   % H(0)=0: initial value
for i2 = 1:length(T)
if HT_flag(T(i2))>0
    % If HT(T) has been calculated, used the saved value    
    H=HT_vec(T(i2));  % Assign the value from HT_vec
else
    % Otehrwise, recursively calculate H(T)
    % i: time from 0 to T-1
      for i=0:(T(i)-1)
          H=H+(1+HT2(T(i)-i-1))*(wblcdf(i+1,Al,Be)-wblcdf(i,Al,Be)); % #####
      end
      % Save the calculated H(T) value
      HT_vec(T(i))=H;
      HT_flag(T(i))=1;
  end
  end
plot(T,HT2(T));
grid on
xlabel('t')
ylabel('COST')
Tareq

Tareq (view profile)

on 11 Aug 2012

what about still give me error?

Matt Fig

Matt Fig (view profile)

on 11 Aug 2012

Please use the {} Code button when pasting code. And be specific in your questions. What did the error message say? I bet it is here:

for i=0:(T(i)-1)

In this line you are defining i for the first time (masking MATLAB's imaginary unit, I might add), so you cannot refer to it in the same line.

Matt Fig

Matt Fig (view profile)

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