How to take value of particular interval from a column?

there is column having arbitrary value from 0-1200 but I have to take only 600-800 from that column? How can I ?

1100    4.7693  13.746  0.08116  308.6983
1160    4.5938  13.24  0.08112  308.68619
1220    4.5577  13.136  0.08109  308.67407
1280    4.9122  14.158  0.08105  308.66205
1340    5.0029  14.419  0.08102  308.64944
1400    4.7408  13.664  0.08099  308.63684
20    4.7447  13.675  0.08096  308.62524
80    4.8635  14.017  0.08093  308.61322
140    4.7867  13.796  0.0809  308.60065
200    4.6726  13.467  0.08088  308.58905
260    4.7121  13.581  0.08086  308.57675
320    4.6942  13.529  0.08083  308.56442

a=xlsread('Book1.xlsx');
k=1;
for i=1:length(a(:,1))
if 600<=a(i,1)>=800
a(i,1)=NaN;
k=k+1;
end
end

Answer 1

[Azzi Abdelmalek]

a(a(:,1)>800 & a(:,1)<1000,1)=nan

[RS]

result is not coming How can I?

How can I improve my result ? result is not coming ? there is column having arbitrary value from 0-1200 but I have to take only 600-800 from that column? How can I ?

1100    4.7693  13.746  0.08116  308.6983
1160    4.5938  13.24  0.08112  308.68619
1220    4.5577  13.136  0.08109  308.67407
1280    4.9122  14.158  0.08105  308.66205
1340    5.0029  14.419  0.08102  308.64944
1400    4.7408  13.664  0.08099  308.63684
20    4.7447  13.675  0.08096  308.62524
80    4.8635  14.017  0.08093  308.61322
140    4.7867  13.796  0.0809  308.60065
200    4.6726  13.467  0.08088  308.58905
260    4.7121  13.581  0.08086  308.57675
320    4.6942  13.529  0.08083  308.56442

a=xlsread('Book1.xlsx');
k=1;
for i=1:length(a(:,1))
if a(a(i,1)>800 & a(i,1)<1000,1)=NaN;
a(i,1)=NaN;
k=k+1;
end
end

How can I improve result?

[Azzi Abdelmalek]

a=xlsread('Book1.xlsx');
k=1;
for i=1:numel(a(:,1))
   if a(i,1)>800 & a(i,1)<1000
        a(i,1)=nan;
    end
end

Answer 2

[Image Analyst]

To extract elements in that range to a new array, try this:

rowIndexesInRange = data(:, column) >= 600 & data(:, column) <= 800;
extractedValues = data(rowIndexesInRange , column);

Note: extractedValues will probably be a smaller size than data. If you want the elements in the same locations but just want others set to zero or some other value, then you'll have to set do

data(~rowIndexesInRange, :) = 0;

This will just zero out elements not in the range and leave elements in range in their original location.

[RS]

How can I improve my result ? result is not coming ? there is column having arbitrary value from 0-1200 but I have to take only 600-800 from that column? How can I ?

1100    4.7693  13.746  0.08116  308.6983
1160    4.5938  13.24  0.08112  308.68619
1220    4.5577  13.136  0.08109  308.67407
1280    4.9122  14.158  0.08105  308.66205
1340    5.0029  14.419  0.08102  308.64944
1400    4.7408  13.664  0.08099  308.63684
20    4.7447  13.675  0.08096  308.62524
80    4.8635  14.017  0.08093  308.61322
140    4.7867  13.796  0.0809  308.60065
200    4.6726  13.467  0.08088  308.58905
260    4.7121  13.581  0.08086  308.57675
320    4.6942  13.529  0.08083  308.56442

a=xlsread('Book1.xlsx');
k=1;
for i=1:length(a(:,1))
if 600<=a(i,1)>=800
a(i,1)=NaN;
k=k+1;
end
end

[Andrei Bobrov]

a(a(:,1) <= 600 | a(:,1) >= 800,1) = nan;

or

a(a(:,1) <= 600 | a(:,1) >= 800,:) = nan;

[RS]

if a(a(:,1) <= 600 | a(:,1) >= 800,1) = nan;
                                       |
Error: The expression to the left of the equals sign is not a valid target for an
assignment.

How can I improve?

[Andrei Bobrov]

all your code

a=xlsread('Book1.xlsx');
a(a(:,1) <= 600 | a(:,1) >= 800,1) = nan;

[Image Analyst]

You can improve it by using the code I gave you. You seemed to totally ignore it. First of all, you don't have any rows where a value in the range 600 to 800 is in column 1. So there's nothing to take out of it. I don't know why you are testing a matrix that does not have the condition you are looking for. So I took your data and made the 80 into 800 so I would have at least one row that fits your criteria. Then look at this code:

data=[...
1100    4.7693  13.746  0.08116  308.6983
1160    4.5938  13.24  0.08112  308.68619
1220    4.5577  13.136  0.08109  308.67407
1280    4.9122  14.158  0.08105  308.66205
1340    5.0029  14.419  0.08102  308.64944
1400    4.7408  13.664  0.08099  308.63684
20    4.7447  13.675  0.08096  308.62524
800    4.8635  14.017  0.08093  308.61322
140    4.7867  13.796  0.0809  308.60065
200    4.6726  13.467  0.08088  308.58905
260    4.7121  13.581  0.08086  308.57675
320    4.6942  13.529  0.08083  308.56442]
column = 1; % This is the column we want to check values of.
rowIndexesInRange = data(:, column) >= 600 & data(:, column) <= 800
extractedValues = data(rowIndexesInRange , :)

And look at the result:

extractedValues =   800  4.8635 14.017  0.08093 308.61322

[RS]

In that row all element should be NaN? How can I?

[Image Analyst]

If "take" means "set to nan" for you (though that seems like a strange definition of take to me), then do this:

data(~rowIndexesInRange, :) = nan;

result will be in data, rather than extractedValues. )You will probably also need cell2mat to turn your cell array from xlsread() into a matrix.)