Question

Given an input array of strings (characters) s, pick out the second column of data and convert it into a column vector of data. Missing data will be indicated by the number 9999. If you encounter missing data, you should set it to the average of the immediately neighboring values. (This is a bit simpler than using `interp1`.)
If the input array is s = [ 'A' '0096' ; 'B' '0114' ; 'C' '9999' ; 'D' '0105' ; 'E' '0112' ]; then the output variable `t` is the following column vector. t = [96 114 109.5 105 112]';
Compose a function read_and_interp which accepts an array in the above format and returns the data converted as specified. You may find the conversion function `str2num` to be useful.
(Using MATLAB Syntax only)

Answer 1

Answer:

Consider the following code.

Explanation:

save the following code in read_and_interp.m

 

function X = read_and_interp(s)

[m, n] = size(s);

X = zeros(m, 1);

for i = 1:m

if(str2num(s(i, 2:5)) == 9999)

% compute value based on previous and next entries in s array

% s(i, 2:5) retrieves columns 2-5 in ith row

X(i,1) = (str2num(s(i-1 ,2:5)) + str2num(s(i+1,2:5)))/2;

else

X(i,1) = str2num(s(i,2:5));

end

end

end

======================

Now you can use teh function as shown below

s = [ 'A' '0096' ; 'B' '0114' ; 'C' '9999' ; 'D' '0105' ; 'E' '0112' ];

read_and_interp(s)

output

ans =

96.000

114.000

109.500

105.000

112.000