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I am trying to write a code that will use a specific column of data to start filling a new array when m(iii)>1, however, it now only gives back the data in the new array when m(iii)>1 so i'm not sure how to fix it. I also want it to collect 720000 data points starting when that first m(iii)>1. Any help would be appreciated, thank you.
length = 720000;
m = acq2.data(:,4);
empty_array2 = zeros(size(length));
for iii = 1:length
if m(iii) > 1
empty_array2(iii) = acq2.data(iii);
end
if iii <= length
end
end

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Gatech AE
Gatech AE 2021-6-8
Be careful naming variables after built-in functions. The "length" function returns the largest dimension of an input. Also, you have size(length) where length is defined as a scalar, so your empty_array2 variable is actually only 1 by 1 in size.

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Star Strider
Star Strider 2021-6-8
Ran in:

0 个投票

Ran in:
I am not certain what you want to do.
Try this —
acq2.data = randi([0 5], 10, 5) % Create Matrix
acq2 = struct with fields:
data: [10×5 double]
idx = acq2.data(:,4) > 1 % Select Rows
idx = 10×1 logical array
1 1 1 0 1 1 0 1 0 1
empty_array = acq2.data(idx,:) % Assign Selected Rows To 'empty_array'
empty_array = 7×5
3 2 3 2 2 2 5 2 3 0 0 4 2 4 3 3 3 4 5 4 4 2 3 4 5 0 2 5 4 2 3 0 1 5 5
This will create ‘empty_array’ with rows of ‘acq2.data’ with values in column 4 are greater than 1. It is probably easier (and more efficient) than the loop.
.

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Sydney Kehoe
Sydney Kehoe 2021-6-8
What I want to do is start collecting data from a certain row (iii) from column 4 of a data set when m(iii)>1 happens for the first time. I only want this to happen once because when it does happen for the first time I want that to be the starting data point and then from there I want 720000 points to be collected from the data set. So ideally I would have a new array that has data starting from row iii of column 4 and then ending at that row iii+720000 if that makes any sense at all?
Star Strider
Star Strider 2021-6-8
Ran in:
Ran in:
I am not certain that I ujnderstand what you want to do.
If you want to collect every row after the first time column 4 is greater than 1, something like this would work:
acq2.data = randi([0 5], 10, 5) % Create Matrix
acq2 = struct with fields:
data: [10×5 double]
Show = acq2.data
Show = 10×5
3 5 1 1 0 1 4 4 4 2 4 5 0 0 1 1 1 5 1 0 3 4 3 5 1 0 0 3 5 5 2 1 5 0 3 2 1 4 1 0 1 2 4 5 5 5 3 2 4 0
start = find(acq2.data(:,4)>1,1,'first')
start = 2
empty_array = acq2.data(start:end,:)
empty_array = 9×5
1 4 4 4 2 4 5 0 0 1 1 1 5 1 0 3 4 3 5 1 0 0 3 5 5 2 1 5 0 3 2 1 4 1 0 1 2 4 5 5 5 3 2 4 0
.
Sydney Kehoe
Sydney Kehoe 2021-6-8
n = 720000;
m = acq2.data(:,4);
empty_array2 = [];
for iii = 1:839272
if m(iii) > 1
empty_array2(iii) = m(iii);
end
if iii <= 839272
end
end
I basically was hoping to put a new column of data into an empty matrix. I want to start to collect this data when m(iii) first is greater than 1. However, this happens more than once so I am not sure how to do it so that I start this new data set when m(iii)>1 for the first time and continues to collect the data through the end of the set. If this doesn't help thank you for your help regardless.
Star Strider
Star Strider 2021-6-8
I’m sorry, however I am now completely confused.
I have no idea what you want to do.
If you can clarify it, ideally with an example, I will see what I can do.
Sydney Kehoe
Sydney Kehoe 2021-6-8
I just worked out a while loop which I think makes more sense but I am going to attempt to do another post since it is a very different format
Star Strider
Star Strider 2021-6-8
Great!
Please supply as many details in your new post as you can. A sample of the data you want to process would be important, as well as an example of the result you want.

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