changeble patern on strfind in embedded matlab function or stateflow

hi all,,

my previous post http://www.mathworks.com/matlabcentral/answers/11244-please-help-strfind-in-stateflow-not-yet-solved talk about strfind with exact pattern:

correct = any(strfind((x')>4,[1 1 1 1 1]))

what if during the x value change, the pattern change too,, for example:

from:

correct = any(strfind((x')>4,[1 1 1 1 1]))

become:

correct = any(strfind((x')>4,[1 1 1 1 1 1 1]))

while the x value increase from 5 to 8,

then the pattern change again if the x value increase from 9 to 12.

become:

correct = any(strfind((x')>4,[1 1 1 1 1 1 1 1 1]))

how we do it on Embedded matlab function or STATEFLOW???

thanks.

Answer 1

[Fangjun Jiang]

Have a second input to your EML, say n, feed a constant block with value of 5, 6, 7, etc, or this input could be a varying signal. Inside your EML, you can generate the [1 1 1 1] vector with ones(1,n);

[Luhur]

what if the x value that change fang???

x value change (for example increase) then the pattern also increase (for example: from [1 1 1 1] become [1 1 1 1 1 1]????

how its gonna be?? like this??

function V=sequence(x)

%#codegen

correct= testinput(x);

if correct

V=10000;

else

V=1;

end

function correct = testinput(x)

eml.extrinsic('strfind');

correct = any(strfind((x')>4,[1,n]));

(how we manage to control the n value of the pattern??? is it give another input from simulink???)

[Fangjun Jiang]

Well, that is up to you. From your description, I thought you want to do:

correct = any(strfind((x')>4,ones(1,n))); where n is a varying number, it could be 5, 6, 7, or 12. That's what you want, right? You could make n the second input of your EML, change those lines accordingly,

function V=sequence(x,n)

correct= testinput(x,n)

function correct = testinput(x,n)

Answer 2

[Luhur]

SORRY... NOT X CHANGE, BUT ANOTHER VARIABLE, LET SAY Y...

Answer 3

[Luhur]

i use this in my EMF fang:

function V=sequence(x,n)
%#codegen
correct= testinput(x,n);
if correct
   V=10;
else
   V=1;
end
function correct = testinput(x,n)
eml.extrinsic('strfind');
correct = any(strfind((x')>4,ones(1,n)));

and still error. it was shown:

*Computed maximum size is not bounded. Static memory allocation requires all sizes to be bounded. The computed size is [1 x :?].

Function 'Embedded MATLAB Function' (#37.186.195), line 11, column 30: "ones(1,n)" Launch diagnostic report.*

[Fangjun Jiang]

Did you feed a value (e.g. Constant 6) to the second input n?

[Luhur]

yes, constant 6, 8, 9 it can be change because i use slider gain fang.

[Fangjun Jiang]

Try put a fixed number first to see if it passed, like correct = any(strfind((x')>4,ones(1,6))) in your EML code. Then add a data type conversion block between your slide gain block and the EML block. I wonder if it requires n to be explicitly specified as an unsigned integer.

Answer 4

[Luhur]

succeed fang,, but its not in sequence...

for example the value:

[1 2 5 5 5 5 5 2 6 6 6 6 6 2 1 1 2 1 1 2] when n=10 supposed to be false. because there was 2 between it. but the condition said it TRUE.

not in sequence.. so???

[Fangjun Jiang]

All I can say is to double check everything. Did you save after modification?

[Luhur]

oh i see, this function correct = any(strfind((x')>4,ones(1,n)));

was not precise in sequence fang??

for example, if n=8 then the value inside it if there was 10 in sequence value then the condition is correct fang???

not precise must 8 in sequence for example???

[Fangjun Jiang]

It's getting harder and harder for me to understand your question. Can you write it in a complete sentense?

[Fangjun Jiang]

If you run it in MATLAB directly, it gives correct result. I suspect you made mistake somewhere else. That's why I asked you to double check everything.

x=[1 2 5 5 5 5 5 2 6 6 6 6 6 2 1 1 2 1 1 2]';

n=10;

correct = any(strfind((x')>4,ones(1,n)))

correct =

0

Answer 5

[Luhur]

haha.. sorry fang... :D

i mean this condition:

correct = any(strfind((x')>4,ones(1,n)));

will TRUE even the result in sequence is more than the n value.

for example n=2, then [5 5 5 2 2] the condition is TRUE right?? because in sequence more than n=2, value 5 mention 3 times a row. not exact must mention 2 times a row.

right???

what about the condition if we want have exact in sequence. i mean, like in the above: for example n=2, then [5 5 5 2 2] the condition is FALSE, because strict to the condition must only 2 times a row.

get it fang???

[Fangjun Jiang]

The answer is YES. If n=2, then when x has 2 or more consecutive value that is great than 4, correct will return TRUE.

[Luhur]

what if we want exact value fang???

i mean, if n=2, then x only true if it has 2 consecutive value that is great than 4.

how fang??

[Fangjun Jiang]

In the case of n=2, x=[5 5 1 5 5], should it return TRUE or FALSE?

[Luhur]

if TRUE the code is???

if FALSE the code is???

Answer 6

[Fangjun Jiang]

TRUE when there is one and only one exact number of consecutive values greater than 4.

correct=length(strfind((x')>4,ones(1,n)))==1

TRUE when there is exact number of consecutive values greater than 4, multiple occurrence is allowed, however, more consecutive values greater than 4 will result in FALSE.

correct=or(isempty(diff(strfind((x')>4,ones(1,n)))),all(diff(strfind((x')>4,ones(1,n)))>1))

I realize that I don't have to make it an one-liner. Using the following two lines is better for readability.

correct=diff(strfind((x')>4,ones(1,n)));
correct=or(isempty(correct),all(correct>1));

[Luhur]

THANK YOU FANG, THANKS AGAIN... :D