Re: [ferret_users] ASCII to netCDF via ferret.

["Oostra, Daniel H. (LARC-E302)[SCIENCE SYSTEMS AND APPLICATIONS, INC]" <daniel.h.oostra@xxxxxxxx>]

Hi Russ,

Thanks for your advice.  This was a rookie error on my part, while the code works, I had somehow decided that it was a 360x180 degree grid, when it was actually a 256x128 degree grid.  So my x and y axes were off.  Once I changed these values for xax and yax the plots came out as intended.

The issue I'm having now is that ferret will only allow me to assign 20 variables.  I'm going to try to break up the data into 20 year blocks but this seems clumsy.  Any idea on how to do this without manipulating the file original data file?

Thanks again,

Dan



On Sep 20, 2011, at 8:34 PM, "Russell Fiedler" <russell.fiedler@xxxxxxxx> wrote:

> 
> Hi Daniel,
> 
> I think the problem is with the way you have defined your time axis. Is it supposed to have values at the
> end of the year or should it represent the middle of the year?
> 
> -------------
> yes? show grid my_grid1
>    GRID MY_GRID1
> name       axis              # pts   start                end
> XAX       LONGITUDE          360mr   180E(-180)           179E
> YAX       LATITUDE           180 r   90S                  89N
> normal    Z
> TAX1      TIME                 2 r   01-JAN-1870 00:00    01-JAN-1871 05:49
> --------------
> 
> If these values are meant to be in the middle of the year then the time axis should be specified as
> 
> define axis/t="01-jan-1870":"01-jan-1871"/npoints=1/edges/units=years tax1
> 
> Note that we put the bounds at the extremes of the year of which the end date is the start of january of the next year
> and not 31 December.
> 
> Another problem might be the length of the lines. You may have to use the /FORMAT="(some_fortran_format)"  
> option on the FILE command.
> 
> Russ
> 
> 
> On Wednesday 21 September 2011 01:11, Oostra, Daniel H. (LARC-E302)[SCIENCE SYSTEMS AND APPLICATIONS, INC] wrote:
>> Hi Ferret users,
>> 
>> I'm trying to use ferret to convert an ASCII Tabular dataset into a netCDF file that I can use in our Live Access Server.
>> 
>> So far I've been able to successfully create plots but they are not coming out correctly.  It seems the data portion is being displayed in the southern hemisphere only.
>> 
>> I've run into some memory problems and variable assignment issues, but both of those can be solved.
>> 
>> Here's a data sample (first 16 lines):
>> 
>> *******************
>> Band Name:                    tas
>> Description:                  (deg. C). NCAR-CCSM3 ensemble average for the IPCC Climate of the 20th Century experiment. This experiment simulates past climate starting from the mid-19th Century and is part of the 4th IPCC Assessment. Data represent averages for 5 ensembles.
>> Holding name:                 air temperature - Annual
>> Collection name:              Climate Changes in the 21st Century
>> Date class:                   time series
>> Begin date of output          1870-01-01
>> End date of output            1999-12-31
>> Time step units:              years
>> Data units:                   Deg C
>> Fill value:                   -99
>> 
>> Center Lon,Center Lat,1870,1871,1872,1873,1874,1875,1876,1877,1878,1879,1880,1881,1882,1883,1884,1885,1886,1887,1888,1889,1890,1891,1892,1893,1894,1895,1896,1897,1898,1899,1900,1901,1902,1903,1904,1905,1906,1907,1908,1909,1910,1911,1912,1913,1914,1915,1916,1917,1918,1919,1920,1921,1922,1923,1924,1925,1926,1927,1928,1929,1930,1931,1932,1933,1934,1935,1936,1937,1938,1939,1940,1941,1942,1943,1944,1945,1946,1947,1948,1949,1950,1951,1952,1953,1954,1955,1956,1957,1958,1959,1960,1961,1962,1963,1964,1965,1966,1967,1968,1969,1970,1971,1972,1973,1974,1975,1976,1977,1978,1979,1980,1981,1982,1983,1984,1985,1986,1987,1988,1989,1990,1991,1992,1993,1994,1995,1996,1997,1998,1999
>> -179.296875,89.296875,-18.2,-17.6,-17.8,-17.5,-17.6,-17.6,-17.8,-17.5,-18.2,-18.0,-17.6,-17.8,-17.9,-18.3,-18.7,-18.8,-18.4,-18.9,-19.1,-19.5,-18.5,-18.9,-19.4,-18.9,-19.1,-19.0,-18.8,-18.7,-18.6,-18.3,-18.0,-18.9,-18.8,-19.5,-19.9,-19.5,-19.6,-19.4,-19.2,-18.5,-19.5,-19.0,-19.2,-19.5,-19.2,-19.0,-18.7,-19.0,-18.6,-18.7,-18.7,-18.4,-18.5,-18.4,-18.3,-18.3,-18.0,-18.8,-18.4,-18.8,-18.9,-18.2,-19.1,-18.2,-18.3,-18.2,-18.5,-17.9,-18.1,-17.9,-18.2,-18.1,-18.2,-18.3,-17.6,-17.8,-18.1,-18.1,-17.4,-17.2,-17.6,-17.6,-17.9,-17.9,-17.9,-17.8,-18.2,-17.0,-17.6,-17.8,-17.4,-17.4,-17.3,-18.0,-17.6,-18.5,-18.0,-17.8,-17.4,-17.1,-16.9,-16.9,-17.1,-17.7,-17.2,-16.9,-17.9,-17.3,-17.1,-17.3,-17.0,-16.8,-16.8,-16.7,-16.7,-16.9,-16.7,-16.4,-16.7,-16.4,-15.6,-16.4,-16.1,-16.4,-15.8,-16.2,-16.4,-15.6,-15.7,-15.3
>> -177.890625,89.296875,-18.2,-17.7,-17.8,-17.5,-17.6,-17.7,-17.8,-17.5,-18.3,-18.0,-17.6,-17.8,-17.9,-18.3,-18.8,-18.8,-18.4,-18.9,-19.1,-19.5,-18.5,-18.9,-19.4,-18.9,-19.1,-19.0,-18.8,-18.7,-18.6,-18.3,-18.0,-18.9,-18.8,-19.5,-19.9,-19.5,-19.7,-19.4,-19.2,-18.5,-19.5,-19.0,-19.2,-19.5,-19.3,-19.0,-18.8,-19.0,-18.6,-18.7,-18.7,-18.4,-18.5,-18.4,-18.3,-18.3,-18.0,-18.8,-18.4,-18.8,-18.9,-18.2,-19.1,-18.2,-18.3,-18.2,-18.5,-18.0,-18.1,-17.9,-18.2,-18.1,-18.2,-18.3,-17.6,-17.8,-18.1,-18.1,-17.4,-17.2,-17.6,-17.6,-17.9,-18.0,-17.9,-17.8,-18.3,-17.0,-17.6,-17.8,-17.5,-17.4,-17.3,-18.0,-17.6,-18.6,-18.1,-17.8,-17.4,-17.1,-16.9,-16.9,-17.1,-17.8,-17.2,-16.9,-17.9,-17.3,-17.1,-17.3,-17.0,-16.8,-16.8,-16.7,-16.8,-17.0,-16.7,-16.4,-16.7,-16.5,-15.7,-16.4,-16.2,-16.4,-15.8,-16.2,-16.4,-15.6,-15.7,-15.4
>> -176.484375,89.296875,-18.2,-17.7,-17.9,-17.5,-17.6,-17.7,-17.8,-17.5,-18.3,-18.1,-17.7,-17.8,-18.0,-18.4,-18.8,-18.9,-18.4,-19.0,-19.1,-19.5,-18.5,-18.9,-19.4,-18.9,-19.1,-19.0,-18.8,-18.7,-18.6,-18.4,-18.0,-18.9,-18.8,-19.6,-19.9,-19.5,-19.7,-19.4,-19.2,-18.6,-19.5,-19.0,-19.2,-19.5,-19.3,-19.1,-18.8,-19.0,-18.6,-18.8,-18.8,-18.4,-18.5,-18.4,-18.3,-18.4,-18.1,-18.9,-18.4,-18.9,-18.9,-18.2,-19.1,-18.2,-18.3,-18.2,-18.5,-18.0,-18.1,-17.9,-18.2,-18.1,-18.3,-18.3,-17.7,-17.8,-18.1,-18.1,-17.5,-17.2,-17.6,-17.6,-17.9,-18.0,-17.9,-17.8,-18.3,-17.0,-17.6,-17.8,-17.5,-17.4,-17.3,-18.0,-17.6,-18.6,-18.1,-17.8,-17.5,-17.1,-16.9,-16.9,-17.2,-17.8,-17.2,-16.9,-17.9,-17.3,-17.1,-17.3,-17.0,-16.8,-16.8,-16.7,-16.8,-17.0,-16.7,-16.5,-16.7,-16.5,-15.7,-16.4,-16.2,-16.4,-15.8,-16.2,-16.5,-15.6,-15.7,-15.4
>> -175.078125,89.296875,-18.2,-17.7,-17.9,-17.5,-17.6,-17.7,-17.8,-17.5,-18.3,-18.1,-17.7,-17.8,-18.0,-18.4,-18.8,-18.9,-18.5,-19.0,-19.1,-19.6,-18.5,-18.9,-19.4,-18.9,-19.1,-19.0,-18.8,-18.7,-18.6,-18.4,-18.0,-18.9,-18.8,-19.6,-19.9,-19.6,-19.7,-19.4,-19.3,-18.6,-19.5,-19.1,-19.2,-19.5,-19.3,-19.1,-18.8,-19.0,-18.6,-18.8,-18.8,-18.4,-18.5,-18.4,-18.3,-18.4,-18.1,-18.9,-18.4,-18.9,-18.9,-18.2,-19.1,-18.2,-18.4,-18.2,-18.6,-18.0,-18.1,-17.9,-18.2,-18.2,-18.3,-18.3,-17.7,-17.8,-18.1,-18.1,-17.5,-17.2,-17.7,-17.6,-17.9,-18.0,-17.9,-17.8,-18.3,-17.0,-17.6,-17.8,-17.5,-17.5,-17.3,-18.0,-17.6,-18.6,-18.1,-17.8,-17.5,-17.1,-17.0,-16.9,-17.2,-17.8,-17.2,-16.9,-18.0,-17.3,-17.2,-17.4,-17.0,-16.9,-16.8,-16.7,-16.8,-17.0,-16.7,-16.5,-16.7,-16.5,-15.7,-16.4,-16.2,-16.5,-15.9,-16.2,-16.5,-15.6,-15.7,-15.4
>> *************
>> 
>> 
>> Here is my ferret script, I'm processing the first 5 years 1870-1874 (of 130 years):
>> 
>> 
>> **********************
>> set memory/size=512
>> 
>> def axis/modulo/x=-180:179/npoints=360/units="degrees_east" xax
>> def axis/y=-90:89/npoints=180/units="degrees_north" yax
>> 
>> define axis/t="01-jan-1870":"31-dec-1870":1/units=years tax1
>> def grid/x=xax/y=yax/t=tax1 my_grid1
>> file/skip=13/var="longitude,latitude,r1870,r1871,r1872,r1873,r1874,r1875,r1876,r1877,r1878,r1879"/grid=my_grid1 "12890ncar_ccm3_tas_EA1-5_20C3M-annual.txt"
>> let air_temp = r1870
>> set variable/title="Monthly, Annual Average Air Tempurature" air_temp
>> set variable/units="Degrees C"/bad=-99 air_temp
>> save/file=air_temp_1870.nc/clobber air_temp
>> 
>> 
>> define axis/t="01-jan-1871":"31-dec-1871":1/units=years tax1
>> def grid/x=xax/y=yax/t=tax1 my_grid2
>> file/skip=13/var="longitude,latitude,r1870,r1871,r1872,r1873,r1874,r1875,r1876,r1877,r1878,r1879"/grid=my_grid2 "12890ncar_ccm3_tas_EA1-5_20C3M-annual.txt"
>> let air_temp = r1871
>> set variable/title="Monthly, Annual Average Air Tempurature" air_temp
>> set variable/units="Degrees C"/bad=-99 air_temp
>> save/file=air_temp_1871.nc/clobber air_temp
>> 
>> define axis/t="01-jan-1872":"31-dec-1872":1/units=years tax1
>> def grid/x=xax/y=yax/t=tax1 my_grid3
>> file/skip=13/var="longitude,latitude,r1870,r1871,r1872,r1873,r1874,r1875,r1876,r1877,r1878,r1879"/grid=my_grid3 "12890ncar_ccm3_tas_EA1-5_20C3M-annual.txt"
>> let air_temp = r1872
>> set variable/title="Monthly, Annual Average Air Tempurature" air_temp
>> set variable/units="Degrees C"/bad=-99 air_temp
>> save/file=air_temp_1872.nc/clobber air_temp
>> 
>> 
>> define axis/t="01-jan-1873":"31-dec-1873":1/units=years tax1
>> def grid/x=xax/y=yax/t=tax1 my_grid4
>> file/skip=13/var="longitude,latitude,r1870,r1871,r1872,r1873,r1874,r1875,r1876,r1877,r1878,r1879"/grid=my_grid4 "12890ncar_ccm3_tas_EA1-5_20C3M-annual.txt"
>> let air_temp = r1873
>> set variable/title="Monthly, Annual Average Air Tempurature" air_temp
>> set variable/units="Degrees C"/bad=-99 air_temp
>> save/file=air_temp_1873.nc/clobber air_temp
>> 
>> 
>> define axis/t="01-jan-1874":"31-dec-1874":1/units=years tax1
>> def grid/x=xax/y=yax/t=tax1 my_grid5
>> file/skip=13/var="longitude,latitude,r1870,r1871,r1872,r1873,r1874,r1875,r1876,r1877,r1878,r1879"/grid=my_grid5 "12890ncar_ccm3_tas_EA1-5_20C3M-annual.txt"
>> let air_temp = r1874
>> set variable/title="Monthly, Annual Average Air Tempurature" air_temp
>> set variable/units="Degrees C"/bad=-99 air_temp
>> save/file=air_temp_1874.nc/clobber air_temp
>> ***********************
>> 
>> Any insights, advice, criticism is welcome!  Thanks ahead.
>> 
>> Bests,
>> 
>> Daniel Oostra (SSAI)
>> NASA/LaRC Atmospheric Sciences Data Center
>> 2 South Wright Street
>> Hampton, VA 23681-2199
>> Ph: 757.864.6157
>> daniel.h.oostra@xxxxxxxx
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>>