help in fwrite a data

[Manish Singh]

Hi all, i am working on sgi machine,my ctl file is as below -
dset  ^time_mean.00%y4.%m2.01.nc
dtype netcdf
options byteswapped big_endian template
undef -1.e+34
xdef 240 linear 0.75 1.5
ydef 134 levels -74.25 -72.75 -71.25 -69.75 -68.25 -66.75 -65.25 -63.75
    -62.25 -60.75 -59.25 -57.75 -56.25 -54.75 -53.25 -51.75 -50.25
    -48.75 -47.25 -45.75 -44.25 -42.75 -41.25 -39.75 -38.25 -36.75
    -35.25 -33.75 -32.25 -30.75 -29.25 -27.75616 -26.28063 -24.83512
    -23.43062 -22.07706 -20.78317 -19.55618 -18.40167 -17.32345
    -16.32345 -15.40167 -14.55617 -13.78317 -13.07706 -12.43062
    -11.83512 -11.28063 -10.75616 -10.25 -9.75 -9.25 -8.75 -8.25
    -7.75 -7.25 -6.75 -6.25 -5.75 -5.25 -4.75 -4.25 -3.75 -3.25
    -2.75 -2.25 -1.75 -1.25 -0.75 -0.25 0.25 0.75 1.25 1.75 2.25
    2.75 3.25 3.75 4.25 4.75 5.25 5.75 6.25 6.75 7.25 7.75 8.25
    8.75 9.25 9.75 10.25 10.75616 11.28063 11.83512 12.43062
    13.07706 13.78317 14.55617 15.40167 16.32345 17.32345 18.40167
    19.55618 20.78317 22.07706 23.43062 24.83512 26.28063 27.75616
    29.25 30.75 32.25 33.75 35.25 36.75 38.25 39.75 41.25 42.75
    44.25 45.75 47.25 48.75 50.25 51.75 53.25 54.75 56.25 57.75
    59.25 60.75 62.25 63.75 65.25
zdef 25 levels 7.5 22.5 37.5 52.5 67.5 82.5 97.5 112.5 127.5 142.5
    158.058 175.1405 194.3055 215.553 238.325 261.655 336.655 463.325
    624.1221 882.1049 1285.536 1860.536 2607.105 3499.122 4488.325
tdef 300  linear 01jan1952 1mo
vars 2
  temp        25  t,z,y,x  Potential Temperature (deg C)
  salinity    25  t,z,y,x  Salinity (ppm-0.035)
endvars

my script to make temperature anomaly is as below -
------------------------------------------------------
'open ocean_4D.ctl'
'set x 20 81'
'set y 7 111'
'set z 1'
'set t 1 12'
'set gxout fwrite'
'set fwrite temp.ind'
'define monavg=ave(temp,t+0,t=300,12)'
'modify monavg seasonal'
'set t 1 300'
'define anomaly=temp-monavg'
'd anomaly'
'disable fwrite'


--------------------------------------------------
but when i am ploting anomaly for t =2 .........then that shows an error
in reading data , i am using grads version of 1.9b4. plz help me so that i
can make data of temperature anomaly .
Any help will be appriciated.