Re: Help for inversing function.

[Ozzy Lash]

On Tue, Jan 17, 2012 at 11:14 AM, kleysonr <address@hidden> wrote:
> Thank you for the anwser,
>
> I have already tried that, but it works only for diff(data, 1) and I need
> also include the first element in the begin of the vector:
>
> data = [73; 83; 135; 200; 288; 300; 267; 251; 302; 381]
>
>> [data cumsum([73;diff(data,1)])]
> ans =
>
>    73    73
>    83    83
>   135   135
>   200   200
>   288   288
>   300   300
>   267   267
>   251   251
>   302   302
>   381   381
>
> But for diff(data, 2), doesn't work.
>
>> [orig cumsum([73;83;diff(orig,2)],2)]
> ans =
>
>    73    73
>    83    83
>   135    42
>   200    13
>   288    23
>   300   -76
>   267   -45
>   251    17
>   302    67
>   381    28
>
> Regards.
> Kleyson Rios.
>
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I think you can get the data back if you know the first original
element and the first difference  (or the first 2 elements)  If your
data is as above,

cumsum([73;cumsum([10;diff(data,2)])]

gets back your data.  73 is the first element of the data, and 10 is
the difference between the second and first elements.

Hope that helps,

Bill