if statements inside a function file and the function called by a for loop
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hi every body im new in matlab and i have this script
clear all
format long
k=100;
dx=1;
x=zeros(k,1);
y=zeros(k,1);
x(1)=1;
for n=2:k;
x(n)=x(n-1)+dx;
[ y ] = test( x );
end
tb=[x(1:k) y(1:k)]
and this function file
function [ y ] = test( x )
if x<25
y=x*2;
elseif x>25
y=x*10;
else
y=x*1000;
end
when i run it just the
else
y=x*1000;
end
part is evaluated, and i want all the x(n) be evaluated in the correct if.
what im doing wrong?
1 Comment
Answers (3)
Walter Roberson
on 25 Jan 2013
An evaluated expression is true when the result is nonempty and contains all nonzero elements (logical or real numeric). Otherwise, the expression is false.
What are you testing? x<25.
How big is x?
Does x<25 result in all non-zero elements?
0 Comments
Roger Stafford
on 25 Jan 2013
Edited: Roger Stafford
on 25 Jan 2013
When you write "y=test(x)" rather than "y=test(x(n))" or "y=test(x(n+!))", you are passing 'test' an x vector with 100 elements in it and the resulting y will also have 100 elements. At the 'if' and 'elseif' points in 'test' each would always require that the given condition hold for all hundred cases of x and that is never true. Hence only the 'else' part is ever executed. Look up the documentation on 'if' and 'elseif'.
2 Comments
MEXICO
on 25 Jan 2013
1 Comment
Walter Roberson
on 25 Jan 2013
Please look in the MATLAB documentation for information about logical indexing.
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