>> B=xlsread('B.xls')
B =
36.3027 51.2517
36.2643 51.2544
36.2613 51.2665
>> B1=B(1); % save old value to later restore
>> B(1)=pi
B =
3.1416 51.2517
36.2643 51.2544
36.2613 51.2665
>> xlswrite('B.xls',B) % write the modified back
>> clear B % ensure isn't cached value in memory...
>> B=xlsread('B.xls') % and see what happens...
B =
3.1416 51.2517
36.2643 51.2544
36.2613 51.2665
>> B(1)=B1;
>> xlswrite('B.xls',B)
>> xlsread('B.xls')
ans =
36.3027 51.2517
36.2643 51.2544
36.2613 51.2665
>>
If can't reproduce the above test or something very similar, submit the test results to TMW official support at www.mathworks.com
Above is from R2012b here but I'd surely expect same result from later revisions, too...
ADDENDUM
I also went and manually changed the spreadsheet and Save'd if from within Excel and read it after each change -- first for the first cell modified from initial value to '=pid()' and then restored the initial value. As expected, the results were --
>> % Modify in Excel and read...
>> xlsread('B.xls')
ans =
3.1416 51.2517
36.2643 51.2544
36.2613 51.2665
>> % Put numeric value back, save and re-read...
>> xlsread('B.xls')
ans =
36.3027 51.2517
36.2643 51.2544
36.2613 51.2665
>>
Seems fine here.
