how to detect vector value in sequence in stateflow

Hi

i have large vector data, let say vector(1x200) in stateflow that the value is between 1 to 10, i want to detect at least 10 consecutive value on that vector (1x200) is bigger than 5 then the action y= 1000, for example:

vector(1x10): X = [3 4 6 6 6 6 7 2 1 3]

in that vector, vector 3 to 7 has value: bigger than 5 and 5 value (3 to 7) in sequence ,, then the condition is accepted so the value y=1000

other example: X = [3 4 6 6 6 6 4 7 1 3]

in that vector, there are vector value that bigger than 5 BUT not 5 value in sequence, cause the vector 7 value is 4,only 4 in sequence, so the condition is not accepted...

vector input value is from simulink, the question is how was the script on stateflow?? or any suggestion???

Answer 1

[Sean de Wolski]

Ahh! Nice clarification.

%Sample Data
X1=[1 1 6 6 6 7 7 2 3 4];% correct
X2=[1 1 6 6 6 7 4 2 3 4];% wrong
X3=[8 8 9 9 8 0 0 1 1 2];% condition: correct
X4=[8 8 9 9 2 8 0 1 1 2];% condition: wr

%Engine
correct = @(x)any(diff(find(diff([0 x]>5)))>=5); %is it correct?

%Checks
correct(X1)
correct(X2)
correct(X3)
correct(X4)

[Luhur]

what if the correct replace by value, if correct then y=1000 (for example)

is that syntax "correct = @(x)any(diff(find(diff([0 x]>5)))>=5);" is how we wrote in stateflow???

[Sean de Wolski]

if correct(X1) %copied from Matt Fig

y = 1000;

else

%whatever

end

[Fangjun Jiang]

Thanks, Sean! I suspect it could be done in a way other than searching but I just couldn't come up with it. Smart!

Answer 2

[Fangjun Jiang]

This task is not that straightforward even in Matlab. I can suggest one way to do it in Matlab. Please chime in if you have other ways.

X=ceil(10*rand(1,200));
A=X>5;
B=num2str(A);
C=strfind(B,repmat('1  ',1,5)); %5 is the number of consecutive occurance
if any(C)
    Y=1000
end

With this, it can be done in Stateflow but it will require using the "ml namespace operator" (see reference "Using Matlab Functions and Data in Actions"). I am not sure if you could pass those obstacles. Maybe you should re-consider your approach and use the Embedded Matlab Function block.

[Sean de Wolski]

I would use diff a few times to find where there are changes and to ensure they're either zero or one. I didn't totally understand the OP's question; however.

[Fangjun Jiang]

What do you mean, Sean? I am not following your comments.

[Sean de Wolski]

consecutive values in a vector (either the same or with an increment of one) will have a value of 0 or 1 when you take the diff of it.

>> diff([0 3 2 4 4 4 4 5 6 9 2])

I think the OP has refined the question and this approach may be wrong. Like I said I don't really understand the question, so nevermind I guess ;-|

[Fangjun Jiang]

What does OP stand for?

[Sean de Wolski]

Original poster.

[Luhur]

to sean de..

it only a simple condition:

1. the value must in sequence in order the place of vector,for example the vector value must have value=4 and 5 times in a row (sequence)

X=[0 0 0 4 4 4 4 4 0 0 0] condition= correct

X=[4 4 4 4 4 0 0 1 1 2 2] condition= correct

X=[0 0 1 1 2 2 4 4 4 4 4] condition= correct

X=[4 0 4 4 4 4 3 2 2 1 1] condition= wrong

2. the value must bigger (>) 5, for example

if we combine two condition above then:

X=[1 1 6 6 6 7 7 2 3 4] condition: correct

X=[1 1 6 6 6 7 4 2 3 4] condition: wrong (because not 5 times in a row and the value of vector (1x7)=4 is bigger than 5)

X=[8 8 9 9 8 0 0 1 1 2] condition: correct

X=[8 8 9 9 2 8 0 1 1 2] condition: wrong (because only 4 times in a row the value is bigger than 5, the vector (1x5)= 2 then its wrong)

to Fangjun, i will try first... thanks...

Answer 3

[Matt Fig]

Another alternative:

correct = @(x) any(strfind(x>5,[1 1 1 1 1]))

if correct(X1)
   y = 1000;
else
   % Whatever
end

[Sean de Wolski]

That takes about 80% of the time mine does.

[Fangjun Jiang]

Thanks, Matt! I didn't know that you can use strfind() directly on data arrays.

[Matt Fig]

This use for FINDSTR and STRFIND is one of those hidden gems of MATLAB! It is very useful and fast...

[Luhur]

THANK YOU SO MUCH SEAN DE, MATT FIG and FANGJUN JIANG... :)

don't know it helps other knowledge... thanks again for fast respond!!

wait my other question... :P