# [ncl-talk] Division problem

Toni Klemm toni-klemm at tamu.edu
Fri Jan 25 06:26:43 MST 2019

```Hi Jalal,

Are you dividing the average January rainfall by the rainfall of a single year to see how it compares? That’s how I understand your code.

Then the problem might be that your individual year has zero rainfall in January, thus division by zero. I had a similar problem. Try to check if your data (jannontc) is zero, and replace zeros with missing values. That way NCL won’t divide. You might get a warning message but it should be okay.

For example:
if (jannontc .eq. 0) then
jannontc = prc at _FillValue
end if

I hope that helps.

Best,
Toni

Toni Klemm, Ph.D.
Postdoctoral Research Associate
Department of Ecosystem Science and Management
College of Agriculture and Life Sciences
Texas A&M University, College Station, TX
Contributor to the Early Career Climate Forum
www.toni-klemm.de | @toniklemm

> On Jan 25, 2019, at 7:13 AM, Md. Jalal Uddin <dmjalal90 at gmail.com> wrote:
>
> Hi all,
>
> I can minus and multiply but cannot divide. NCL says, "divide by 0 cannot continue". Any suggestions?
>
> ;January
>  prc =f->pre(:,{65:110},{0:30})
>  prc_reorder = prc(time|:,latitude|:,longitude|:)
>
> ; January TCs average rainfall
>  ntim = (/12,13,14,15,16,34,35,36,37/)
>  tcjan = prc_reorder(ntim,:,:)
>  tcavgjan = dim_avg_n_Wrap(tcjan,0)
>
> ; January contribution
> totjan = dim_sum_n_Wrap(prc_reorder,0)
> jantc = dim_sum_n_Wrap(tcjan,0)
> jannontc = totjan - jantc
> copy_VarMeta(totjan,jannontc)
>
> jancont = jantc / jannontc    ; problem from there
> copy_VarMeta(jantc,jancont)
>
> --
> Md. Jalal Uddin
> MSc in Applied Meteorology (English Language)
> Nanjing University of Information, Science and Technology, China
> B.Sc. in Disaster Management (Hons.)
> Patuakhali Science and Technology University, Bangladesh.
> Cell: +8613260859092, +8801792052662
> Web: www.dmjalal90.weebly.com