Based on Column 3 values how to get specific column 1 values?

I have 3 columns of data coming from excel, Please find attached txt file, for instance in the attached txt file when column C is '0', i would like to get the value of column A at that point and the two more values above it i.e 2301,2300,2244 in the attached file.

Answer 1

[jonas]

fid = fopen('sample.txt')
out = textscan(fid,'%f%f%f','headerlines',1);
fclose(fid)
A = cell2mat(out);

id0 = find(A(:,3) == 0);
idc = [id0,id0-1,id0-2];
idc = unique(idc) 
idc(idc<1) = [];
A(idc, 1)

ans =

        2244        2300        2301

works for multiple zeros as well

[raghavendra kandukuri]

Hey Jonas, how to get the corresponding column C values

[jonas]

What do you mean? For other values such as 0.5 and 1? Just change this line

id0 = find(A(:,3) == 0);
                     ↑ change here

Note that I've updated the answer. There was a bug previously where the script would return an error if the target was either the first or the second row, because in that situation "two previous values" does not exist.

[raghavendra kandukuri]

no, i mean 2244,2300, 2301 are column A values, so i want the corresponding column c values for them, which would be (1,0.5,0) i guess and thanks for bug fixing

[jonas]

A(idc, 3)

Should do it. Have not tested it myself.

[raghavendra kandukuri]

Yup, worked. Thank you Jonas

[jonas]

Cheers!