[Gate-users] how to add two uncertainty matrix with each other?

[Mery MB]

Hi Dear David

I calculated the squared as well beside the dose and uncertainty by the
following scripts:

/gate/actor/addActor                           DoseActor meshdose
/gate/actor/meshdose/save                      output1/Randodose.hdr
/gate/actor/meshdose/attachTo                  phantom
/gate/actor/meshdose/stepHitType               random
/gate/actor/meshdose/setSize                   512 512 177 mm
#/gate/actor/meshdose/setResolution            512 512 177
/gate/actor/meshdose/setVoxelSize              3 3 1 mm
/gate/actor/meshdose/enableEdep                true
/gate/actor/meshdose/enableUncertaintyEdep     true
/gate/actor/meshdose/enableSquaredEdep         true
/gate/actor/meshdose/enableDose                true
/gate/actor/meshdose/saveEveryNSeconds         60
#/gate/actor/meshdose/normaliseDose            true
#/gate/output/allowNoOutput


Based on the article that you suggest abd the gate manual* (the part that I
highlighted):*

The unit of edep is MeV and the unit of dose is Gy. The dose/edep squared
is used to calculate the uncertainty when the output
from several files are added. The uncertainty is the relative statistical
uncertainty. "SquaredDose" flag allows to store the sum of
squared dose (or energy). It is very useful when using GATE on several
workstations with numerous jobs.


* To compute the finaluncertainty, you only have to sum the dose map and
the squared dose map to estimate the final uncertainty according to
theuncertainty equations.*

when i run the program two times, I should sum the dose map and the squared
dose map for both job? like below?

first job(dose map+squared dose map)+second job(dose map+squared dose
map)=uncertainty



*best *

*Mery*



On Wed, Jun 20, 2018 at 10:08 AM David Sarrut <
David.Sarrut at creatis.insa-lyon.fr> wrote:

> Hello,
>
> to add uncertainties, you need the squared values (obtained from the
> DoseActor via a flag), see for example in:
> https://www.ncbi.nlm.nih.gov/pubmed/16798417
>
> Sincerely,
> David
>
> On Tue, Jun 19, 2018 at 8:21 AM Mery MB <mery.mb.mph at gmail.com> wrote:
>
>> Dear Gate user
>>
>> I simulate a phantom and run the program two times for reducing the
>> uncertainty in voxels. I want to know how I can add two uncertainty with
>> each other?
>>
>> Best
>> Mery
>> _______________________________________________
>> Gate-users mailing list
>> Gate-users at lists.opengatecollaboration.org
>> http://lists.opengatecollaboration.org/mailman/listinfo/gate-users
>
>
>
> --
> David Sarrut, Phd
> Directeur de recherche CNRS
> CREATIS, UMR CNRS 5220, Inserm U1206
> Centre de lutte contre le cancer Léon Bérard
> 28 rue Laënnec, 69373 Lyon cedex 08
> Tel : 04 78 78 51 51 / 06 74 72 05 42
> http://www.creatis.insa-lyon.fr/~dsarrut
> _________________________________
>  "2 + 2 = 5,  for extremely large values of 2"
> _________________________________
>
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