how to find difference between column elemnts in a matrix ?
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Let my matrix is
3 2 14 5
7 1 8 9
11 11 12 13
I need to find the substraction between column 1 and 2 and store the result in coulmn 1. similarily for coulmn 3 and 4 and result will be in coulmn 2. i.e the result should be like this
1 9
6 -1
0 -1
kindly, suggest solution. Thank you.
采纳的回答
A general solution (without hard-coded columns):
>> M(:,1:2:end) - M(:,2:2:end)
ans =
1 9
6 -1
0 -1
EDIT: if you have uint8 image data, then convert to double first:
double(M(:,1:2:end)) - double(M(:,2:2:end))
6 个评论
aditya sahu
2017-6-13
aditya sahu
2017-6-13
@aditya sahu: it is likely that you have an unsigned integer matrix: many images are saved as uint8, and in MATLAB the output of arithmetic using uint8 is also uint8 (for which zero is the lowest value).
If that is the case you could easily convert to signed integer:
int16(M(:,1:2:end)) - int16(M(:,2:2:end))
You should pick an appropriate integer class which can encode all of your data:
Walter Roberson
2017-6-13
double(M(:,1:2:end)) - double(M(:,2:2:end)) would run less risk of overflowing datatypes
aditya sahu
2017-6-14
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