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Hi Yogesh, Yes, you certainly can. If you want to save data at locations that are scattered in space, you can use the "constant array" syntax to define lists of those x and y locations, and then use the SAMPLEXY function to create a new variable, where the x and y dimensions are collapsed onto a single dimension. This will be an abstract X axis, whose first point corresponds to (x1,y1), second point to (x2,y2), and so on, For instance yes? use input_file.nc yes? let xpts = {140,150,155} yes? let ypts = {-10,30,20} yes? let co2points = samplexy(co2,xpts,ypts) yes? save/clobber/file=output_filen.nc/title=\ "co2 at xpts={140,150,155},ypts={-10,30,20}" c02points This will keep the time and Z axis as they were on input. The X axis will be an abstract axis of length three, so the first corresponds to the input data at (140,-10), the second to (150,30, and so on). I used the SAVE/TITLE= option to document the locations; you could also save the values of xpts and ypts along with the data variable, or use LET/TITLE= to assign a title to the variable co2points when you define it. If the points where you want to save your variable are on any sort of grid, either regularly spaced or irregularly spaced, you can define new axes and use regridding. The @XACT or @NRST regridding transformations would be best for selecting data out of the original variable without define axis/x=0:360:10/units=degrees xnew define axis/y=-90:90:10/units=degrees ynew ! OR, irregularly spaced axes define axis/x/units=degrees xnew = {140,150,155,170} define axis/y/units=degrees ynew = {-10,0,20,30} save/clobber/file=newfile.nc co2[gx=xnew@xact,gy=ynew@xact] This will keep other dimensions as they were in the input file, and the output X and Y locations on the new grid. Ansley Manke Yogesh K. Tiwari wrote: Hello Ferret Users, Is it possible to split any netcdf file inside ferret on the basis of grid values. For example : I have four dimentional co2 mixing ratio field(i,j,k,l) in netcdf format. I want take out the co2 mixing ratio value from this field only at some grid points like (140,-10), (150,30), (155,20) ...... and so on, on certain time, and then I want to make another netcdf file. Is it possible ?? Thanks. Regards, Yogesh -- |