How can i code for problems which have range

hello there friends previously i have posted here and its been a great help...Today i want to ask regarding how to code for range values ...Example :-0.3<x<0.3.I understood that i need to use for or If loop for this and the general syntax for loop is

for variable =c:g:h

statements

end

so i tried something like this

for dn=1:1:365

if (-0.3>sdelta)&&(sdelta<0.3)

fprintf('number of days : %d',dn)

end

end

but i couldnt get the desired output.Can anyone help me out or guide me ?Thank You.

Answer 1

[DGM]

I'm not sure if this is exactly where you're going with your example, but let's say you have a vector and you want to print a message for each element that falls within a range. You could do that with a loop like you show.

roomtemperature = [38 41 16 26 34 21 32 12 27 36]; % average temp per day
comfortablerange = [22 27];

for k = 1:numel(roomtemperature)
    iscomfortable = roomtemperature(k)>=comfortablerange(1) ...
                 && roomtemperature(k)<=comfortablerange(2);
    if iscomfortable
        fprintf('The room temp was a comfortable %d°C on day %d\n',roomtemperature(k),k)
    end
end

The room temp was a comfortable 26°C on day 4
The room temp was a comfortable 27°C on day 9

If you want to do something other than print messages, it may be better to extract this information as logical vectors and use that to perform some desired tasks by indexing. This obviates the loop.

iscomfortable = roomtemperature>=comfortablerange(1) ...
              & roomtemperature<=comfortablerange(2);

avgcomfortabletemps = mean(roomtemperature(iscomfortable))

avgcomfortabletemps = 26.5000

minuncomfortabletemps = min(roomtemperature(~iscomfortable))

minuncomfortabletemps = 12

maxuncomfortabletemps = max(roomtemperature(~iscomfortable))

maxuncomfortabletemps = 41

[prem kumar]

owh yes i want to achieve similar to yours but in my case its a large number of vector example in my case is dn is actually number of days in a year and sdelta is the angle of solar declination..So what i want to achieve is that for that particular sdelta range from -0.3:0.3 i want to obtain how many days in between.

[DGM]

sdelta = 4*rand(1,365)-2; % test data [-2 2]
targetangle = [-0.3 0.3];

% create logical mask
gooddays = sdelta >= targetangle(1) ...
         & sdelta <= targetangle(2);

% count nonzero elements of mask
numberofgooddays = nnz(gooddays)

numberofgooddays = 59

[prem kumar]

friend do you mind if you could explain the lines so it gives me a better understanding?