how to write if statement into for loop?

Hi all,

I have scattered data and I want to put them together and exclude the other which is not locate along the main axis, the statement of excluded data is

 Longitude>43

and the loop is

 for i=1:24
    t_interp(:,i)=interp1(z(~isnan(z(:,i)),i),t(~isnan(t(:,i)),i),depth);
    s_interp(:,i)=interp1(z(~isnan(z(:,i)),i),sal(~isnan(t(:,i)),i),depth);  
end

i cant understand how to write it into the loop, I'm appreciate anyone can help me sorry for my bad English thank you in advance

[Star Strider]

It looks as though you just did write it in a loop.

• What is it not doing that it should?
• What is it doing that it should not?
• Do the interp1 statements work outside of the loop?

[dpb]

Think he means to how include the condition, SS...

@lina, what is the variable for Longitude? Need more info...

[lina]

the code is for reading data from xls file, Longitude is exists in the file which include 24 stations between 30-45 longitudes the one I dont need it in loop is that >43 which equal to station 4 (by using x=find(Longitude>43) ans=4)

so i need to replace the station 4 values to nan (its also have some nan elements) to interpolate 23 station values

what should i do?

Answer 1

[dpb]

Need storage arrangement to be precise, but if you have vectors of same length where Longitude is given for each element, then simply

z(Long>43)=nan;

will do the trick. Or, you could simply select the values to operate on and ignore the rest...

zprime=z(Long<43);

If z is a 2D array will need the (:) operator for the alternate dimension to pick up all rows or columns depending on whether the selected index is column or row, respectively.

Look up "logical addressing" in the documentation -- it's a key element of Matlab syntax and utilization.

[lina]

ok thank you

[dpb]

So did that solve the problem? If so, how about "Accepting" the answer; if not, show the actual storage scheme.