.TH r.series.accumulate 1grass "" "GRASS 8.2.1" "GRASS GIS User's Manual"
.SH NAME
\fI\fBr.series.accumulate\fR\fR  \- Makes each output cell value a accumulationfunction of the values assigned to the corresponding cells in the input raster map layers.
.SH KEYWORDS
raster, series, accumulation
.SH SYNOPSIS
\fBr.series.accumulate\fR
.br
\fBr.series.accumulate \-\-help\fR
.br
\fBr.series.accumulate\fR [\-\fBnzf\fR]  [\fBbasemap\fR=\fIname\fR]   [\fBinput\fR=\fIname\fR[,\fIname\fR,...]]   [\fBfile\fR=\fIname\fR]  \fBoutput\fR=\fIname\fR  [\fBscale\fR=\fIfloat\fR]   [\fBshift\fR=\fIfloat\fR]   [\fBlower\fR=\fIname\fR]   [\fBupper\fR=\fIname\fR]   [\fBrange\fR=\fImin,max\fR]   [\fBlimits\fR=\fIlower,upper\fR]   [\fBmethod\fR=\fIstring\fR]   [\-\-\fBoverwrite\fR]  [\-\-\fBhelp\fR]  [\-\-\fBverbose\fR]  [\-\-\fBquiet\fR]  [\-\-\fBui\fR]
.SS Flags:
.IP "\fB\-n\fR" 4m
.br
Propagate NULLs
.IP "\fB\-z\fR" 4m
.br
Do not keep files open
.IP "\fB\-f\fR" 4m
.br
Create a FCELL map (floating point single precision) as output
.IP "\fB\-\-overwrite\fR" 4m
.br
Allow output files to overwrite existing files
.IP "\fB\-\-help\fR" 4m
.br
Print usage summary
.IP "\fB\-\-verbose\fR" 4m
.br
Verbose module output
.IP "\fB\-\-quiet\fR" 4m
.br
Quiet module output
.IP "\fB\-\-ui\fR" 4m
.br
Force launching GUI dialog
.SS Parameters:
.IP "\fBbasemap\fR=\fIname\fR" 4m
.br
Existing map to be added to output
.IP "\fBinput\fR=\fIname[,\fIname\fR,...]\fR" 4m
.br
Name of input raster map(s)
.IP "\fBfile\fR=\fIname\fR" 4m
.br
Input file with raster map names, one per line
.IP "\fBoutput\fR=\fIname\fR \fB[required]\fR" 4m
.br
Name for output raster map
.IP "\fBscale\fR=\fIfloat\fR" 4m
.br
Scale factor for input
.br
Default: \fI1.0\fR
.IP "\fBshift\fR=\fIfloat\fR" 4m
.br
Shift factor for input
.br
Default: \fI0.0\fR
.IP "\fBlower\fR=\fIname\fR" 4m
.br
The raster map specifying the lower accumulation limit, also called baseline
.IP "\fBupper\fR=\fIname\fR" 4m
.br
The raster map specifying the upper accumulation limit, also called cutoff. Only applied to BEDD computation.
.IP "\fBrange\fR=\fImin,max\fR" 4m
.br
Ignore values outside this range
.IP "\fBlimits\fR=\fIlower,upper\fR" 4m
.br
Use these limits in case lower and/or upper input maps are not defined
.br
Default: \fI10,30\fR
.IP "\fBmethod\fR=\fIstring\fR" 4m
.br
This method will be applied to compute the accumulative values from the input maps
.br
Options: \fIgdd, bedd, huglin, mean\fR
.br
Default: \fIgdd\fR
.br
\fBgdd\fR: Growing Degree Days or Winkler indices
.br
\fBbedd\fR: Biologically Effective Degree Days
.br
\fBhuglin\fR: Huglin Heliothermal index
.br
\fBmean\fR: Mean: sum(input maps)/(number of input maps)
.SH DESCRIPTION
\fIr.series.accumulate\fR calculates (accumulated) raster value
using growing degree days (GDDs)/Winkler indices\(cqs, Biologically
Effective Degree Days (BEDD), Huglin heliothermal indices or an average
approach from several input maps for a given day. Accumulation of e.g.
degree\-days to growing degree days (GDDs) can be done by providing a
\fIbasemap\fR with GDDs of the previous day.
.PP
The flag \fB\-a\fR determines the average computation of the input raster maps.
In case the flag is not set, the average calculation is:
.br
.nf
\fC
    average = (min + max) / 2
\fR
.fi
In case the flag was set, the calculation changes to arithmetic mean
.br
.nf
\fC
    average = sum(input maps) / (number of input maps)
\fR
.fi
.PP
\fBGDD\fR Growing Degree Days are calculated as
.br
.nf
\fC
    gdd = average \- lower
\fR
.fi
.PP
In case the \fB\-a\fR is set, the Winkler indices are calculated instead
of GDD, usually accumulated for the period April 1\ust\d to October
31\ust\d (northern hemisphere) or the period October
1\ust\d to April 30\uth\d
(southern hemisphere).
.PP
\fBBEDDs\fR Biologically Effective Degree Days are calculated as
.br
.nf
\fC
    bedd = average \- lower
\fR
.fi
with an optional upper \fIcutoff\fR applied to the average instead of
the temperature values.
.PP
The \fBHuglin heliothermal index\fR is calculated as
.br
.nf
\fC
    huglin = (average + max) / 2 \- lower
\fR
.fi
usually accumulated for the period April 1\ust\d to September
30\uth\d (northern hemisphere) or the period September
1\ust\d to April 30\uth\d (southern hemisphere).
.PP
\fBMean\fR raster values are calculated as
.br
.nf
\fC
    mean = average
\fR
.fi
.PP
For all the formulas \fImin\fR is the minimum value, \fImax\fR
the maximum value and \fIaverage\fR the average value.
The \fImin\fR, \fImax\fR and \fIaverage\fR values
are automatically calculated from the input maps.
.PP
The \fIshift\fR and \fIscale\fR values are applied directly to
the input values. The \fIlower\fR and \fIupper\fR maps, as well
as the \fIrange\fR options are applied to constrain the
accumulation. In case the \fIlower\fR and \fIupper\fR maps are
not provided the \fIlimits\fR option with default values will be
applied.
.PP
If an existing map is provided with the \fIbasemap\fR option, the
values of this map are added to the output.
.SH NOTES
The \fIscale\fR and \fIshift\fR parameters are used to transform
input values with
.br
.nf
\fC
    new = old * scale + shift
\fR
.fi
.PP
With the \fI\-n\fR flag, any cell for which any of the
corresponding input cells are NULL is automatically set to NULL
(NULL propagation) and the accumulated value is not calculated.
.PP
Negative results are set to 0 (zero).
.PP
Without the \fI\-n\fR flag, all non\-NULL cells are used for calculation.
.PP
If the \fIrange=\fR option is given, any values which fall outside
that range will be treated as if they were NULL. Note that the range is
applied to the scaled and shifted input data. The \fIrange\fR
parameter can be set to \fIlow,high\fR thresholds:
values outside of this range are treated as NULL (i.e., they will be
ignored by most aggregates, or will cause the result to be NULL if \-n
is given). The \fIlow,high\fR thresholds are floating point, so use
\fI\-inf\fR or \fIinf\fR for a single threshold (e.g.,
\fIrange=0,inf\fR to ignore negative values, or
\fIrange=\-inf,\-200.4\fR to ignore values above \-200.4).
.PP
The maximum number of raster maps that can be processed is given by the
user\-specific limit of the operating system. For example, the soft limits
for users are typically 1024 files. The soft limit can be changed with e.g.
ulimit \-n 4096 (UNIX\-based operating systems) but it cannot be
higher than the hard limit. If the latter is too low, you can as superuser
add an entry in:
.br
.nf
\fC
/etc/security/limits.conf
# <domain>      <type>  <item>         <value>
your_username  hard    nofile          4096
\fR
.fi
This will raise the hard limit to 4096 files. Also have a look at the
overall limit of the operating system
.br
.nf
\fC
cat /proc/sys/fs/file\-max
\fR
.fi
which on modern Linux systems is several 100,000 files.
.PP
Use the \fB\-z\fR flag to analyze large amounts of raster maps without
hitting open files limit and the \fIfile\fR option to avoid hitting
the size limit of command line arguments.
Note that the computation using the \fIfile\fR option is slower
than with the \fIinput\fR option.
For every single row in the output map(s) all input maps are
opened and closed. The amount of RAM will rise linearly with the number
of specified input maps. The \fIinput\fR and \fIfile\fR options are
mutually exclusive: the former is a comma separated list of raster map
names and the latter is a text file with a new line separated list of
raster map names.
.SH EXAMPLES
Example with MODIS Land Surface Temperature, transforming values from
Kelvin * 50 to degrees Celsius:
.br
.nf
\fC
r.series.accumulate in=MOD11A1.Day,MOD11A1.Night,MYD11A1.Day,MYD11A1.Night out=MCD11A1.GDD \(rs
      scale=0.02 shift=\-273.15 limits=10,30
\fR
.fi
.SH SEE ALSO
\fI
g.list,
g.region,
r.series,
r.series.interp
\fR
.PP
Hints for large raster data processing
.SH REFERENCES
.RS 4n
.IP \(bu 4n
Jones, G.V., Duff, A.A., Hall, A., Myers, J.W., 2010.
Spatial analysis of climate in winegrape growing regions in the
Western United States. Am. J. Enol. Vitic. 61, 313\-326.
.RE
.SH AUTHORS
Markus Metz and Soeren Gebbert (based on r.series)
.SH SOURCE CODE
.PP
Available at:
r.series.accumulate source code
(history)
.PP
Accessed: Sunday Jan 22 07:36:28 2023
.PP
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.PP
© 2003\-2023
GRASS Development Team,
GRASS GIS 8.2.1 Reference Manual