right ... there is not Beta_hat_0 in FSL - it's just my way of saying
estimate of baseline regressor parameter - (the one I'm after). In
case you're wondering, I'm trying to use it to estimate spin density.
thanks again
-L
On Jun 23, 2009, at 12:23 PM, Mark Jenkinson wrote:
> Hi,
>
> In FSL there is no pe0 or beta_hat_0 file as we remove
> the mean prior to setting up the GLM. Hence there is
> no constant (mean) regressor and so no parameter estimate
> (or variance) associated with that.
>
> I'm not sure where you are getting Beta_hat_0 from.
>
> All the best,
> Mark
>
>
> On 23 Jun 2009, at 16:28, Luis Hernandez wrote:
>
>> thanks, Mark.
>>
>> Beta_hat_0 is the same as the mean (assuming no pre-whitening), but
>> I don't think the variance estimate of Beta_hat_0 the same as the
>> variance of the signal. oh, well...
>>
>>
>> -Luis
>>
>>
>>
>>
>> On Jun 23, 2009, at 10:59 AM, Mark Jenkinson wrote:
>>
>>> Hi,
>>>
>>> If you are talking about the mean signal as the baseline regressor
>>> then
>>> I'm afraid the answer is no. We do not remove the mean signal via a
>>> regressor, but instead remove it from the signal and the model in
>>> the
>>> pre-statistical filtering. Hence we do not generate values or
>>> variances
>>> for it. But it is easy to calculate the mean using fslmaths and -
>>> Tmean
>>> on the original data if that is all you want.
>>>
>>> All the best,
>>> Mark
>>>
>>>
>>> On 23 Jun 2009, at 15:49, Luis Hernandez wrote:
>>>
>>>> Dear FSL experts,
>>>>
>>>> Is there a way to get FSL to dump the parameter estimate for the
>>>> baseline regressor into a file, like pe0? (It looks like the
>>>> mean_func file might do the trick ... is this right?) BUT more
>>>> importantly, how about its variance estimate? can that be dumped
>>>> out? FEAT writes out varcope files based on the specified
>>>> contrasts but I don't see how to make a contrast that uses the
>>>> baseline regressor, since it is kind of "hidden" ?
>>>>
>>>> I apologize if I missed something obvious. thanks in advance
>>>>
>>>> -Luis
>>>>
>>>> --
>>>> ( http://www.eecs.umich.edu/~hernan )
>>>>
>>>
>>>
>>
>> --
>> ( http://www.eecs.umich.edu/~hernan )
>>
>
>
--
( http://www.eecs.umich.edu/~hernan )
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