HOW TO MAKE THE nan VALUE DISAPPEAR from my extraction, I also like someone to help me make a dynamic figure representing the evolution of the wind per day.

files='wind.nc'

fles='pressure.nc'
%TIME
TIMEP=ncread(fles,'time'); %PRESSURE
TIMEW=ncread(files,'time'); %WIND
Pression=ncread(fles,'pbo');
Wind=ncread(files,'wind_speed');
%LONGITUDE AN LATITUDE 

%PRESSURE
LONP=double(ncread(fles,"longitude"));
LATP=double(ncread(fles,"latitude"));

%WIND
LONW=double(ncread(files,"lon"));
LATW=double(ncread(files,"lat"));

%extraction wind

[val,ila]=min(abs(LATW-3.25));
[val1,ilo]=min(abs(LONW-9.25));
W=NaN(1,length(dtw));
for i=1:length(dtw)
    ss=Wind(ilo,ila,i);
    Sal(i)=ss;
end

%extraction pressure
[val,ila]=min(abs(LATP-3.25));
[val1,ilo]=min(abs(LONP-9.25));
PRS=NaN(1,length(dt));
for i=1:length(dt)
    ss=Pression(ilo,ila,i);
    Sal(i)=ss;
end

%when I run my script, there is the value nan which appears in W
%I also like someone to help me make a dynamic figure representing the 
% evolution of the wind per day, coordinate point Lon 9.325 and lat 3.25
%thank you in advance

Answer 1

[dpb]

unzip('wind1.zip')
d=dir('w*.nc');
info=ncinfo(d(1).name);
info.Variables(:).Name

ans = 'se_model_speed'

ans = 'time'

ans = 'lat'

ans = 'lon'

ans = 'wind_to_dir'

ans = 'northward_wind'

ans = 'wind_speed'

ans = 'eastward_wind'

t=ncread(d(1).name,'time');
Wind=ncread(d(1).name,'wind_speed');
heatmap(sum(isnan(Wind),3))

It appears the NaN values are concentrated in specific areas around the edge and with a couple of bands and one localized area towards the west-central region (by visual position, not nececessarily actual geographically; didn't look at the coordinates. As such, one presumes there's a reason for so many NaN and it probably isn't wise to do anything about substituting for them, at least not without some additional knowledge of where these data were taken and what they're actually measurements of.

Just for grins, let's see what time traces might look like at some specific points --

W=[squeeze(Wind(1,1,:)) squeeze(Wind(4,7,:)) squeeze(Wind(10,11,:)) squeeze(Wind(16,17,:))]; 
whos W

  Name         Size            Bytes  Class     Attributes

  W         1035x4             33120  double              

N=size(W,2);
for i=1:N, subplot(N,1,i); plot(t,W(:,i));xlim([t(1) t(end)]);nnz(isnan(W(:,i))), end

ans = 400

ans = 397

ans = 912

ans = 1035

So, for the first couple, it's mostly there with some holes; the last two are almost or completely lacking any values; it wouldn't be possible to fill in those values from anything reasonable.

The variables in the file make one wonder if maybe there's something else going on -- the directions in the other variable names, specifically. Might the missing wind_speed values be recorded as with direction elsewhere instead? Methinks you probably need to understand more fully just what the dataset actually represents.

[dpb]

ADDENDUM: OBTW, the attached pressure.zip file error'ed on trying to unzip it...

[Victor Ebolo]

• thank you @dp this will help me but I want W to be a size variable (1x1026)
• because I'm going to manipulate it with variables of this shape and size. please how to do it?

[dpb]

Which 1026 points would you want to select and why?