How can I calculate average from specific rows to another rows in a datatable?

Dear community

I'm trying to design a script, in order to calculate the average from the 1st to 3rd row, then from the 4th to 6th and finally from the 7th to 9th row. The data has this structure:

Comment Cell Temperature

 24-04-2019 A8            38,76736069 
 24-04-2019 A8            38,70141602 
 24-04-2019 A8            39,03113937 
 24-04-2019 C5            38,56953049 
 24-04-2019 C5            39,29491806 
 24-04-2019 C5             39,26194382 
 24-04-2019 E1             36,5252533 
 24-04-2019 E1             36,6241684 
 24-04-2019 E1             36,36038971 

The temperature are in the 6th column. These data are like datatable. I have this script:

Clean=table2cell(datatable);
nrow = height(datatable); 
lastidx = floor(nrow/3) * 3;
T_p = mean(reshape(datatable{1:lastidx,6}, 3, []));
T_C=T_p.';

But doesn´t work. How can I do?

Any for loop?

Help please.

Thank U

[dpb]

Looks ok on surface; what does "doesn't work" mean? Error (if so, give us the error text in context with all red text pasted) or what???

[Jonathan Bijman]

Doesn’t show an matlab error. When I calculate the average of each group of Measurements in excel, the matlab results don’t match with the first ones.

[dpb]

Well, we can't say anything about numbers w/o data to look at. Maybe Excel isn't the same set, who knows??? Certainly the general idea of reshape() in memory storage order works as can be easily demonstrated...for a local variable D from your data above--

>> mean(reshape(D,3,[])).'
ans =
   38.8333
   39.0421
   36.5033
>> mean([D(1:3) D(4:6) D(7:9)])
ans =
   38.8333   39.0421   36.5033
>> 

[Jonathan Bijman]

It’s the same data. Previously I import all Excel files as datatable and the idea is matlab calculate the average of the three groups of Measurements as explain before.

[Jonathan Bijman]

When I apply the last commands appears this error

mean(reshape(Clean,3,[])).'

Error using sum
Invalid data type. First argument must be numeric or logical.
Error in mean (line 127)
        y = sum(x, dim, flag) ./ mysize(x,dim);
Error in Untitled2 (line 23)
mean(reshape(Clean,3,[])).'

mean([Clean(1:3) Clean(4:6) Clean(7:9)])

Error using sum
Invalid data type. First argument must be numeric or logical.
Error in mean (line 127)
        y = sum(x, dim, flag) ./ mysize(x,dim);
Error in Untitled2 (line 23)
T=mean([Clean(1:3) Clean(4:6) Clean(7:9)])

I have 35 files with the structure I wrote at the beginning

I dunno what to do

[Jonathan Bijman]

@dpb I already fixed it.

Thanks anyway =)