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From: Michael on 12 Aug 2010 01:01
hi,

i have 2 vectors input as follow:

a = [0;1;1;0;1;0;0;0;0;1]
b = [0;0;0;0;0;0;0;-1;0;0]

and the output i am trying to generate is
c = [0;1;1;1;1;1;1;0;0;1]

whereby the logic is as follow:
1. if a is '1', c='1'. ('ON' mode)
2. if a is in 'ON' mode, c will always be '1'.
3. if b is '-1', c='0'. ('OFF' mode)
4. if b is in 'OFF' mode, c will always be '0'.

may i ask if there is any matlab function that does this logic?
or is there any efficient ways of getting the output instead of using for-loop?

thanks in advance for sharing!

cheers!
Michael
From: Michael on 12 Aug 2010 01:15
sry for multiple submission, kindly delete this thread.

thx mod.
From: Sean on 12 Aug 2010 09:08
"Michael " <mteo(a)empiricap.com> wrote in message <i3vv6j$kfu$1(a)fred.mathworks.com>...
> hi,
>
> i have 2 vectors input as follow:
>
> a = [0;1;1;0;1;0;0;0;0;1]
> b = [0;0;0;0;0;0;0;-1;0;0]
>
> and the output i am trying to generate is
> c = [0;1;1;1;1;1;1;0;0;1]
>
> whereby the logic is as follow:
> 1. if a is '1', c='1'. ('ON' mode)
> 2. if a is in 'ON' mode, c will always be '1'.
> 3. if b is '-1', c='0'. ('OFF' mode)
> 4. if b is in 'OFF' mode, c will always be '0'.
>
> may i ask if there is any matlab function that does this logic?
> or is there any efficient ways of getting the output instead of using for-loop?
>

C =
> thanks in advance for sharing!
>
> cheers!
> Michael

Your 'c' example doesn't comply with your rules. Why is c(1) ==0 and c(4) ~=0?

I think you're looking for something like this though
c = a | (b>0); %| is the logical 'or' symbol.
From: Matt Fig on 12 Aug 2010 09:28
Your example does not follow the rules you set out. Also, your rules don't seem clear enough to decide in every case. For example, you say that if a is ON then c is always 1, and if b is OFF then c is always 0. But what is c when BOTH a is ON AND b is OFF?

A consistent set of logical rules will not have such ambiguities in it!
From: Roger Stafford on 12 Aug 2010 20:15
"Michael " <mteo(a)empiricap.com> wrote in message <i3vv6j$kfu$1(a)fred.mathworks.com>...
> hi,
>
> i have 2 vectors input as follow:
>
> a = [0;1;1;0;1;0;0;0;0;1]
> b = [0;0;0;0;0;0;0;-1;0;0]
>
> and the output i am trying to generate is
> c = [0;1;1;1;1;1;1;0;0;1]
>
> whereby the logic is as follow:
> 1. if a is '1', c='1'. ('ON' mode)
> 2. if a is in 'ON' mode, c will always be '1'.
> 3. if b is '-1', c='0'. ('OFF' mode)
> 4. if b is in 'OFF' mode, c will always be '0'.
>
> may i ask if there is any matlab function that does this logic?
> or is there any efficient ways of getting the output instead of using for-loop?
>
> thanks in advance for sharing!
>
> cheers!
> Michael
- - - - - - - - - - -
My guess is that you mean that if a = 1, that puts things in an 'on' mode which causes c to become a 1 and stay that way until a value in b puts it in the 'off' mode by becoming -1. When the latter happens, c will turn to 0 and stay there until a again brings it back to the 'on' mode. Matt has already pointed one weakness. How does it behave when a "wants" an 'on' mode and b an 'off' mode at the same time? Another weakness is, what mode do you wish c to start in initially if both a and b start with 0's?

I will assume that if both a and b contradict each other, then you will leave the mode the way it was. Also it is assumed that initially the mode starts at 'off'.

n = length(a);
c = zeros(size(a));
A = a==1;
B = b~=-1;
m = false; % Mode is 'off' initially
for k = 1:n
m = A(k)&&B(k)||A(k)&&m)||B(k)&&m;
c(k) = +m;
end

Roger Stafford
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