ok so there is no simple tool for this I just do this manually.
On Feb 20, 2007, at 2:39 PM, Saad Jbabdi wrote:
> Hi,
> You can compute the mean by adding all your 4d images using avwmaths
> with
> the "-add" option and then dividing by the number of 4d images.
> For the std, you can use the formula: std=sqrt(sum(x_i^2)/n - mean^2)
> i.e. you compute the mean of the squares (combining "-sqr" and "-add")
> and
> then substract the square of the mean ("-sqr" and "-sub") and then take
> the square root of the result ("-sqrt").
>
> Saad.
>
>
>> Hi All
>>
>> I see how I can take the mean over time of a voxel using avwmaths.
>> however, I have several timeseries images, all the same length and
>> all
>> registered to the same space, and for each timepoint, I want an
>> average
>> of all the different images. I aslo wante the standard deviation. how
>> do I do that?
>>
>> Thanks
>>
>> Jen
>
>
Jennifer Bramen
UCLA Brain Mapping Center
660 Charles Young Dr. So
Los Angeles, CA 90095
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