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Hi Dan, I'm just tuning in from the wings ... ignore if I'm in left field. Normally in Ferret you'd read data such as this onto a single variable -- i.e. you would create a time axis for your grid that encompasses all of the years and a 3D grid of shape lon-lat-year. Then you won't see this artificial limitation in the number of distinct variables that you can read. It looks like the way the file is organized each year is a separate column. The year number is in effect the "fastest moving axis" of a grid of shape year-lon-lat. This is permuted from Ferret's default ordering. You'll want to
========================== On 9/20/2011 6:36 PM, Oostra, Daniel H. (LARC-E302)[SCIENCE SYSTEMS AND APPLICATIONS, INC] wrote: 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 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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 |