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Consecutive numbers without rain

Added by Guilherme Martins over 7 years ago

Hi cdo users,

I'm trying to calculte the consecutive numbers without rain using the values less than 1 mm/day.

My file input is: tmp.nc and the output is: a1.nc

I've used the command below to do that:

cdo -consects -lec,1 tmp.nc a1.nc

But I want only the first ocurrence and not all values like the result below:

-1 :       Date     Time   Level Gridsize    Miss :     Minimum        Mean     Maximum : Parameter name
1 : 2015-01-01 12:00:00 0 1 1 : nan : prec
2 : 2015-01-02 12:00:00 0 1 1 : nan : prec
3 : 2015-01-03 12:00:00 0 1 1 : nan : prec
4 : 2015-01-04 12:00:00 0 1 1 : nan : prec
5 : 2015-01-05 12:00:00 0 1 1 : nan : prec
6 : 2015-01-06 12:00:00 0 1 0 : 4.0000 : prec <== I want only this value, that is, only the firs ocurrence.
7 : 2015-01-07 12:00:00 0 1 1 : nan : prec
8 : 2015-01-08 12:00:00 0 1 1 : nan : prec
9 : 2015-01-09 12:00:00 0 1 1 : nan : prec
10 : 2015-01-10 12:00:00 0 1 1 : nan : prec
11 : 2015-01-11 12:00:00 0 1 1 : nan : prec
12 : 2015-01-12 12:00:00 0 1 1 : nan : prec
13 : 2015-01-13 12:00:00 0 1 0 : 1.0000 : prec
14 : 2015-01-14 12:00:00 0 1 1 : nan : prec
15 : 2015-01-15 12:00:00 0 1 1 : nan : prec
16 : 2015-01-16 12:00:00 0 1 0 : 2.0000 : prec
17 : 2015-01-17 12:00:00 0 1 1 : nan : prec
18 : 2015-01-18 12:00:00 0 1 1 : nan : prec
19 : 2015-01-19 12:00:00 0 1 0 : 2.0000 : prec
20 : 2015-01-20 12:00:00 0 1 1 : nan : prec

Cheers,

Guilherme Martins.


Replies (2)

RE: Consecutive numbers without rain - Added by Ralf Mueller over 7 years ago

What about the eca_cdd (Consecutive dry days index per time period)

ram@luthien:~ cdo -h eca_cdd                                                                                                                                                                                               [12:54:40|16-12-06]
NAME
    eca_cdd - Consecutive dry days index per time period

SYNOPSIS
    eca_cdd[,R[,N]]  ifile ofile

DESCRIPTION
    Let ifile be a time series of the daily precipitation amount RR, then the largest number 
    of consecutive days where RR is less than R is counted. R is an optional parameter with 
    default R = 1 mm. A further output variable is the number of dry periods of more than N days.
    The date information of a timestep in ofile is the date of the last contributing timestep in ifile.
    The following variables are created: 
    - consecutive_dry_days_index_per_time_period
    - number_of_cdd_periods_with_more_than_<N>days_per_time_period

PARAMETER
    R  FLOAT    Precipitation threshold (unit: mm; default: R = 1 mm)
    N  INTEGER  Minimum number of days exceeded (default: N = 5)

RE: Consecutive numbers without rain - Added by Guilherme Martins over 7 years ago

Hi Ralf,

Perfect!

Thanks a lot!

Guilherme.

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