[GRASS-user] 10day accumulation which t.rast module to use?

[Veronica Andreo]

Hello Emma,

2014-12-03 23:47 GMT-03:00 maning sambale <emmanuel.sambale at gmail.com>:

> Dear Vero,


> Thanks for the reply.  But t.rast.aggregate does not do what I intend
> to do.  My rainrate is from a span of 20 days.
> t.rast.aggregate produces (as expected) two rasters, one for each of
> the 10day accumulation.  What I want for example is like a moving sum,
> where for each day, it calculates the sum for the past 10 days.
>
>
Oh, I see... then, t.rast.accumulate is what you need. The default method
"mean" does the sum.

Maybe, something like this (please re-check the cycle and granularity
parameters, i didn't test)

t.rast.accumulate input=3hr_rainrate output=10day_acum_precip
base=10day_acc_prec start="2001-01-01" end="2001-01-20" cycle="10 days"
granularity="1 days" method=mean

Hope it helps now :)

Cheers,
Vero

On Thu, Dec 4, 2014 at 4:31 AM, Veronica Andreo <veroandreo at gmail.com>
> wrote:
> > Hi Emmanuel,
> >
> >> Hi,
> >>
> >> I have 3hourly rainrate data for a given region in a GRASS temporal
> >> database (strds).
> >>
> >> I want to aggregate the data by summing all raster from the previous
> >> 10 days to calculate the accumulated rainfall.
> >> The temporal modules have several tools:
> >> t.rast.series
> >> t.rast.accumulate
> >> t.rast.aggregate
> >> t.rast.mapcalc
> >>
> >> >From the manual, the appropriate module seems to be t.rast.accumulate
> >> but it does not have sum in the method parameters. Currently, I'm
> >> running several r.series commands for each day like below:
> >>
> >> r.series input=\
> >> "`t.rast.list input=3hr_rainrate where=\
> >> "('${DATE} 00:00:00' >= datetime(start_time, '3 hours')) \
> >> and ('${DATE} 00:00:00' <= datetime(start_time, '10 days')) " \
> >> col=name method=comma`" \
> >> output="test_2014-07-20" method=sum
> >>
> >> Then, register each layer in another strds:
> >>
> >> #Create a new STRDS
> >> t.create output='10day_accumulation' type='strds'
> temporaltype='absolute'
> >> \
> >>             title='10day_accumulation' \
> >>             description="10 day rainfall accumulation"
> >>
> >>
> >> g.mlist type='rast', pattern='test*', separator=','
> >>
> >> #Register the r.series output to the strds
> >> t.register -i type=rast input=10day_accumulation \
> >>         start="2014-07-10 00:00:00" increment="1 days" separator="," \
> >>         maps="`g.mlist type='rast', pattern='test*', separator=','`"
> >>
> >>
> >> Is there another approach using directly any of the t.rast.* modules.
> >> For a time-line visualization, here's what I want to do:
> >> https://dl.dropboxusercontent.com/u/2096185/sample_accumulation.png
> >>
> >> Thanks!
> >
> > If i understood right, something like
> >
> > t.rast.aggregate input=3hr_rainrate output=10day_rain basename=10day_rain
> > granularity='10 days' method=sum
> >
> > should do the what you need.
> >
> > HTH,
> >
> > Vero
>
>
>
> --
> cheers,
> maning
> ------------------------------------------------------
> "Freedom is still the most radical idea of all" -N.Branden
> wiki: http://esambale.wikispaces.com/
> blog: http://epsg4253.wordpress.com/
> ------------------------------------------------------
>
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