Thread Subject:

How to find x > threshold value for a fixed consecutive days?

Hi,

Kindly assist the following:

I would like to find a series of x >= 130 for a minimum 3 consecutive days.

data = [126 122 130 136 112 135 138 145 109 120 119 131 180 155 130]

Given data, the answer should be 135, 138 and 145 for the first series and 131 180 155 and 130 for the second series.

I only know how to use the find function to figure out the threshold value but not the second condition.

Really looking forward for suggestions to set up the code.

Thanks very much.

data = [126 122 130 136 112 135 138 145 109 120 119 131 180 155 130]

i=diff([0 data>=130 0]);
i1=find(i==1);
i9=find(i==-1);
l=(i9-i1);
b=l>=3;
i1=i1(b);
i9=i9(b)-1;
c=arrayfun(@(i1,i9) data(i1:i9), i1, i9, 'unif', 0);

c{:}

% Bruno

Karren, you can get this in one single line of code if you have the Image Processing Toolbox:

% Generate some sample data.
data = [126 122 130 136 112 135 138 145 109 120 119 131 180 155 130]

% Get all regions >= 130 that bigger than 3 elements.
measurements = regionprops(bwareaopen(data>=130, 3), data, 'PixelValues');

% All done. Now, print them out.
for k = 1 : length(measurements)
measurements(k).PixelValues
end

"Bruno Luong" <b.luong@fogale.findmycountry> wrote in message <jvo8dc$h1q$1@newscl01ah.mathworks.com>...
> data = [126 122 130 136 112 135 138 145 109 120 119 131 180 155 130]
>
> i=diff([0 data>=130 0]);
> i1=find(i==1);
> i9=find(i==-1);
> l=(i9-i1);
> b=l>=3;
> i1=i1(b);
> i9=i9(b)-1;
> c=arrayfun(@(i1,i9) data(i1:i9), i1, i9, 'unif', 0);
>
> c{:}
>
> % Bruno

Thanks Bruno... The code provided really helps. But I still have one more question. Can I write the output c{:} to excel? I tried a couple times but I didn't get it. Kindly advise!

Karren

ImageAnalyst <imageanalyst@mailinator.com> wrote in message <5f0420d6-c0f3-4488-b273-8fce83218279@googlegroups.com>...
> Karren, you can get this in one single line of code if you have the Image Processing Toolbox:
>
> % Generate some sample data.
> data = [126 122 130 136 112 135 138 145 109 120 119 131 180 155 130]
>
> % Get all regions >= 130 that bigger than 3 elements.
> measurements = regionprops(bwareaopen(data>=130, 3), data, 'PixelValues');
>
> % All done. Now, print them out.
> for k = 1 : length(measurements)
> measurements(k).PixelValues
> end

> Hi,
> No.. I do not have the Image Processing Toolbox. Anyway, thanks very much for the suggestion.

Karren

"Bruno Luong" <b.luong@fogale.findmycountry> wrote in message <jvo8dc$h1q$1@newscl01ah.mathworks.com>...
> data = [126 122 130 136 112 135 138 145 109 120 119 131 180 155 130]
>
> i=diff([0 data>=130 0]);
> i1=find(i==1);
> i9=find(i==-1);
> l=(i9-i1);
> b=l>=3;
> i1=i1(b);
> i9=i9(b)-1;
> c=arrayfun(@(i1,i9) data(i1:i9), i1, i9, 'unif', 0);
>
> c{:}
>
> % Bruno

Hi Bruno,

What if I only need the first (and subsequent) output(s) starting from the 3rd consecutive number that exceed 130? For this case, the answer should be

ans = 145
ans = 155 and 130

Thanks very much for helping.

Karren

"Karren" wrote in message <k0ccbi$744$1@newscl01ah.mathworks.com>...

>
> What if I only need the first (and subsequent) output(s) starting from the 3rd consecutive number that exceed 130? For this case, the answer should be
>
> ans = 145
> ans = 155 and 130

Please replace the appropriate command with this:

c=arrayfun(@(i1,i9) data(i1:i9), i1+2, i9, 'unif', 0);

Bruno