Dear all,
Actually I am able to find the dates of highest gridpoint rainfall events in a 3 D dataset but the problem is the model dataset I am using seems to have many grid point stroms resulting in many maxima's that occur only in a grid but having no rainfall in surrounding grid. To avoide this problem I am wonding whether it would be possible to define a maxima event that also take into account rainfall in the grids surrounding the maximum rainfall grid (e.g. say rainfall in surrounding 1/3 of the
grids i.e. 8 out of sorround 24 grids is above a threshold (e.g. 10% of the maxamima or a fix threshold)).
I am using following script to find the dates of 10 highest gridpoint rainfall maxima:
(actually the list may contain more than one maxima value in a given data (corresponding extereme rainfall occuring in more than one grid on the same data) but I am sorting uniqe dates in excel)
let sorted_i1=sorti(xsequence(pr[X=79:89,Y=26:31]))
let sorted_pr=samplei(xsequence(pr[X=79:89,Y=26:31]),sorted_i1)
let isize=sorted_pr[i=@ngd]
list sorted_pr[i=`isize-9`:`isize`], sorted_i1[i=`isize-9`:`isize`] ! This would list the 10 highest rainfall and i-values corresponding to those max
I could then find the date (timestep) by dividing those i-values with number of grids in each time step (say 800 for the region above in the dataset) and then adding 1 and ignoring the decimal points from the result i.e.
list (sorted_i1[i=`isize-9`:`isize`]/800)+1 ! would list the time steps of occurance of 10 highest rainfall
For the problem I mentioned above,
one opition I can think of is to intepolate the model output to a coarser grid and then repeat above procedure but I wonder if there is a better alternative.
Best regards,
Jagadish