looping through multiple numbers

I have written a script, which tells me which rows of A are above the threshold, and then the difference between the numbers in column 1 of the variable 'abovethresh'.

This works fine, however I now want to write a loop which gives me this output, for avsize = 1:1:45. So I want it to apply the new threshold and do the same thing. I've tried to get a small section of this working to build on but I am getting the error below.

%single value
avsize = 10; %define avalanche threshold 

abovethresh = A(A(:, 2) > 10,:);
wait_time = diff(abovethresh(:,1));
wait_time = wait_time(wait_time >15,:);

%loop
avsize = [1:1:45]
for i = 1:length(avsize)
a_t(i) = A(A(:,2) > avsize,:);
end 


The logical indices in position 1 contain a true value outside of the array bounds.
 

Answer 1

[Walter Roberson]

a_t(i) = A(A(:,2) > avsize(i),:);

[C.G.]

Thank you, can I ask a follow up question?

I am trying to save the output of every iteraton of w_t. I know I need to index this as w_t(i), but when I do this I get the error:

A = [t Q];
avsize = [1:1:5]; %define range of avalanche thresholds
for i = 1:length(avsize)
a_t = A(A(:,2) > avsize(i),:); %find the rows above each threshold
w_t = diff(a_t(:,1)); 
w_t(i) = w_t(w_t >15,:);
end 

Unable to perform assignment because the left and right sides have a different number of elements.
 

[Torsten]

W_t{i} = w_t(w_t >15,:);

[C.G.]

I get the following error by implementing that line:

Unable to perform assignment because brace indexing is not supported for variables of this type.

[Walter Roberson]

w_t = diff(a_t(:,1)); 
w_t(i) = w_t(w_t >15,:);

You create w_t as a numeric column vector. You take a subset of it on the next line. You try to assign the subset to the single location in the same vector, w_t(i) which is a problem if the subset has more than one element.

If by chance you succeed on the assignment, then the next iteration you overwrite all of w_t

[C.G.]

so are you saying I need to change the name of w_t(i) so it is not the same as the line above?

If i do that I get exactly the same error message.

[Walter Roberson]

all_w_t{i} = w_t(w_t >15,:);