re-griding

[Dawit]

Hi All,

I was trying to regrid prcipitation nc file to higher resolution, but getting an error message: : ncap2: ERROR assign(): LHS cast for latn - cannot make RHS ~zz@value_list conform. I run the script below using ncap2 command as follows:

ncap2 -v -S pre_rgrid.nco pre_cru_1901_2014.nc pre_cru_new_1901_2014.nc

/*****/
defdim("latn",7);
defdim("lonn",17);
// change to your new range here
latn[$latn] = {30, 32.5, 35, 37.5, 40, 42.5, 45, 47.5, 50, 52.5, 55, 57.5, 60};
// change to your new range here
lonn[$lonn] = {-17.5, -15, -12.5, -10, -7.5, -5, -2.5, 0, 2.5, 5, 7.5, 10, 12.5, 15, 17.5, 20 ,22.5, 25, 27.5};
out[$latn,$lonn]=0.0;

// no time dimension
pre_cru_new[$latn,$lonn]=0.0;
for( idx=0 ; idx<$time.size ; idx++ ) {
pre_cru_new(idx,:,:)=bilinear_interp(pre_cru_new(0,:,:),out,latn,lonn,lat,lon);
}

I would appreciate if you share your experince how this challange is addressed.

Dawit

[henry Butowsky]

Hi Dawit,
you are mixing things up a bit:

lantn[$latn] should have 7 elements on the Right Hand Side (RHS) you have 10
lonn[$lonn] should have 17 elements on the RHS , you have 19

the call to bilinear_interp() should look something like this - i am assuming that the variable that you wish to regrid is pre_cru($time,$lat,$lon):

`/****/
defdim("latn",7);
defdim("lonn",17);
// change to your new range here
latn[$latn] = {30, 32.5, 35, 37.5, 40, 42.5, 45};
// change to your new range here
lonn[$lonn] = {-17.5, -15, -12.5, -10, -7.5, -5, -2.5, 0, 2.5, 5, 7.5, 10, 12.5, 15, 17.5, 20 ,22.5};
out[$latn,$lonn]=0.0;

out[$latn,$lonn]=0.0;
pre_cru_new[$time,$latn,$lonn]=0.0;

for(idx=0;idx<$time.size;idx++)(
pre_cru_new(idx,:,:)=bilinear_interp(pre_cru(idx,:,:),out,latn,lonn,lat,lon);

}
/****/`

if you still have troubles can you please put your netcdf file in an accessible place and then i can have a go
...Henry

`

[Dawit]

Dear Henry,

Thank you for your response. I made the corrections and tried but seems I made a syntax error somewhere. When checked against your suggestion above I could not fined the problem with my script. The error message this time is

(my_ncl) Dagemawes-MacBook-Pro:CRU_TS_PRE dawitabebe$ ncap2 -v -S regrid_cru.nco pre_cru_1901-2014_dat.nc pre_cru_new_1901_2014_dat.nc

regridcru.nco:15:77: expecting ), found ';'

I wanted to send the file but I don't know how! I wonder if you could share your e-mail address so as I can send through.

my script for scrutiny
/*****/

defdim("lat_new", 13);
defdim("lon_new",23);
// new lat range
latn[$latn] = {3.25, 3.5, 3.75, 4.0, 4.25, 4.75, 5.0, 5.25, 5.75, 6.0, 6.25};

// new lon range
lonn[$lonn] = {36.25, 36.5, 36.75, 37.0, 37.25, 37.5, 37.75, 38.0, 38.25, 38.5, 38.75, 39.0, 39.25, 39.5, 39.75, 40.0, 40.25, 40.5, 40.75, 41.0, 41.25, 41.5, 41.75};
out[$latn,$lonn]=0.0;

out[$latn,$lonn]=0.0;
pre_cru_new[$time,$latn,$lonn]=0.0;
for(idx=0;idx<$time.size;idx++)(
pre_cru_new(idx,:,:)=bilinear_interp(pre_cru(idx,:,:),out,latn,lonn,lat,lon);

}

/**/
Thanks again

Dawit

[henry Butowsky]

Hi Dawit,
only send file if <20 meg other wise my email provider rwill barf
henryb at ntlworld dot com

[Dawit]

Hi Henry

Thank you so much for your support. Attached the file (only 957 KB).

Dawit

[Dawit]

Hi Henry,

I am just wondering if the file has ended in you mail box.

Thanks
Dawit

[henry Butowsky]

yep got it will look tomorrow

On 4/28/2017 at 7:10 PM, "Dawit" wrote:

Hi Henry,

I am just wondering if the file has ended in you mail box.

Thanks

Dawit

re-griding

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[Charlie Zender]

Please use syntax formatting widgets to format code. Your script as printed above contains this:

for(idx=0;idx<$time.size;idx++)(
pre_cru_new(idx,:,:)=bilinear_interp(pre_cru(idx,:,:),out,latn,lonn,lat,lon);
}

Change the opening parenthesis to a brace:

for(idx=0;idx<$time.size;idx++){

[Dawit]

Dear Charlie,

I'm not just good at this! With the correcion you noted still have an error message

ncap2 -v -S regrid_cru_script.nco pre_cru_1901-2014_dat.nc pre_cru_new_1901_2014_dat.nc
ncap2: ERROR ncap_cst_mk(): Unrecognized dimension "latn"in LHS subscripts

Sorry for bothering you, I'm just learning

Thanks for your patience

Dawit

[henry Butowsky]

HI Dawit,
Pls try the following script

/****************/`
defdim("latn",3);
defdim("lonn",5);
// the number of values here on RHS must equal the latn dim size
latn[$latn] = {3.5,4.5,5.5};
// the number of values here on RHS must equal the lonn dim size
lonn[$lonn] = {37.0,38.0,39.0,40.1 ,40.9};
out[$latn,$lonn]=0.0;

pre_cru_new[$time,$latn,$lonn]=0.0;
for(idx=0;idx<$time.size;idx++)
{
pre_cru_new(idx,:,:)=bilinear_interp(pre(idx,:,:),out,latn,lonn,lat,lon);
}
/************/

...Henry