### Hello kity (view profile)

on 11 Dec 2012

Hi,

I have an excel file with data.

an example

```colom1:
1
2
3
4
5
empty
empty
6
7
8
9
10
empty
empty
```

What I want to do is this:

• get every number above the first empty cell (in example the number 5 and 10)
• then calculate, 5 - 1 , 5 -2 , 5-3 ,5-4

same for the next set of data (10-6 10-7 10-8 10-9), this for the entire colom.

With xlsread I read the file, then select the colom with num(:,x). I get an arraw with numbers then 2 Nanns between each set of data....

what then to do...

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### Vishal Rane (view profile)

on 11 Dec 2012

Use isnan and find functions.

```a = [ 1 2 3 4 5 NaN NaN 6 7 8 9 10 NaN NaN 11 12]
```
```find(isnan(a))
```

will give you the locations of all NaN in the array.

Vishal Rane

### Vishal Rane (view profile)

on 11 Dec 2012

Use the NaN locations to further build your logic

### Hello kity (view profile)

on 11 Dec 2012
Edited by Hello kity

### Hello kity (view profile)

on 11 Dec 2012

I used isnan and find. That gives me a new array with all the locations of the isnans.

for example

1 2 3 4 5 NaN NAn

I get 6 and 7 as NaN... but how can I say if you find the 6th as NaN then use the 5th to calculate, 5-1 and 5-2 etc..

thank you