Re: [ferret_users] modulo and edges problem

Hello Ansley,

Following is what I tried to do and what I obtained.How can get edges eleminated.For clarity I have highligheted the changes I would like to eliminate.

us myfile.nc
sh da
name title                                            I          J             K         L
X_T Geographic Longitude of T_cell     1:150     1:150     ...         ...
Y_T Geographic Longitude of T_cell     1:150     1:150     ...         ...

can axis/modulo `Y_T,RETURN=yaxis`
can axis/modulo `Y_T,RETURN=xaxis`
Sav/file=test.nc X_T,Y_T

original file:

dimensions:
grid_x_t = 150;
grid_y_t = 150;
........
.......
variables:
float grid_x_T(grid_x_T) ;
  grid_x_T:long_name = "Nominal Longitude of T-cell center;
  grid_x_T:units = "degree_east" ;
  grid_x_T:cartesian_axis = "X" ;
float grid_y_T(grid_y_T) ;
  grid_y_T:long_name = "Nominal Latitude of T-cell center;
  grid_y_T:units = "degree_north" ;
  grid_y_T:cartesian_axis = "Y" ;
double x_T(grid_y_T,grid_x_T)
.........
.........

double Y_T(grid_y_T,grid_x_T)
.........
.........

new file:

dimensions:
grid_x_t = 150;
grid_y_t = 150;
grid_y_tedges = 151;
........
.......
variables:
double grid_x_T(grid_x_T) ;
  grid_x_T:units = "degree_east" ;
  grid_x_T:point_spacing = "even" ;
  grid_x_T: "X";
double grid_y_T(grid_y_T) ;
  grid_y_T:units = "degree_north" ;
  grid_y_T:point_spacing = "uneven" ;
  grid_y_T: "Y" ;
  grid_Y_Tedges:edges = "" ;
float x_T(grid_y_T,grid_x_T)
.........
.........

float Y_T(grid_y_T,grid_x_T)
.........
.........

----- Original Message -----

From: Ansley Manke

To: Anita Gera

Cc: ferret_users@noaa.gov

Sent: Wednesday, August 31, 2005 11:20 PM

Subject: Re: [ferret_users] Fw: modulo

Hi Anita,
When you did the CANCEL AXIS/MODULO command, did you intend to apply that to the X axis? From what you say, it looks like you watnted it to apply to the X axis, but have specified the Y axis instead. Also, the syntax is can axis/modulo `my_var,return=yaxis` (not var=my_var).

Ferret automatically sets longitude axes as moduo, if the range of the axis is less than or equal to 360 degrees, but you can turn off the modulo setting with CANCEL AXIS/MODULO `my_var, return=xaxis`

Please write back if I've missed what you were intending to ask.

Ansley

Anita Gera wrote:

Hello,

If I do the following , I am obtaining extra edges and modulo in the output file .

use my_file

can axis/modulo `var=my_var,return=yaxis`
save/clobber/file=my_file.nc my_var

I see, the x-axis is now modulo. Originally:
dimensions:

    my_var=150

..............

..................
float xt_i(xt_i) ;
xt_i:long_name = "Longitude of T points" ;
xt_i:units = "degrees_E" ;
xt_i:cartesian_axis = "X" ;

new file:

dimensions:
    my_var=150

    my_varedges=151

..............

..................

double XT_I(XT_I) ;
XT_I:units = "degrees_east" ;
XT_I:modulo = 360. ;
XT_I:point_spacing = "uneven" ;
XT_I:axis = "X" ;
XT_I:bounds = "XT_I_bnds" ;

Can someone please solve.