h5read - howto read values in hexadecimal
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Dear all, currently I'm trying to write h5-files containing singles into a sql-database expecting floats (single).
Matlab reads the data of the h5 files into singles. Due to the use of sprintf and a matrix containing singles and doubles I unfortunately need to change them to double. Otherwise the values of the generated sprintf gets weird.
So I'm searching for a way howto read the h5 files as hexadecimal, therefore not altering the values and transferring them in hexadecimal to my sql-database.
I would be very pleased to get help - since I did not find anything on google.
This is the code I'm using:
conn =database.ODBCConnection('FirstTryLocal','user','Password');
for mint=1:10;
maxt=mint;
countt=maxt-mint+1;
for minlat=1:36:360-35;
maxlat=minlat+35
countlat=maxlat-minlat+1;
minlon=1;
maxlon=540;
countlon=maxlon-minlon+1;
n=datenum('20120101000000','yyyymmddHHMMSS');
cutstart=[minlat minlon mint];
cutlength=[36 maxlon maxt-mint+1];
evap= double(h5read('path','/data',cutstart,cutlength));
v50= double(h5read('path','/data',cutstart,cutlength));
t=1:countt;
lat=minlat:maxlat;
lon = minlon:maxlon;
datum=round(str2num(datestr(n+(mint+t-2)./24,'yymmddHH')));
a = repmat(datum', [countlon*countlat 1]);
b = repmat(lat,[countlon countt]);
c = repmat(lon',[countt countlat]);
d = permute(evap,[2 1 3]);
m = permute(v50,[2 1 3]);
str5=sprintf('\r\n (%d%03d%03d, %d, %i, %i, %d, %d), ', [a(:)'; b(:)'; c(:)'; a(:)'; b(:)'; c(:)'; m(:)']);
%str5=sprintf('\r\n (%d), ', [a(:)']);
sqlquery = strcat('INSERT INTO datanew (ID, datum, lat, lon, evap, v50) VALUES ',str5);
insertQuery = [sqlquery(1:end-1),';'];
response=exec(conn,insertQuery);
if isempty(response.Message)
else
disp(strcat('Error during import of time ',num2str(datum(1)),' and ',num2str(datum(end)),', ',num2str(minlat),', ',num2str(maxlat),', ',num2str(minlon),', ',num2str(maxlon)));
disp(response.Message)
if strcmp(response.Message,'ODBC Driver Error: [ma-1.0.6][10.1.19-MariaDB]MySQL server has gone away')
disp('This Error appears due to the size of the SQL-Query. Please reduce the amout of data transfered. E.g. 360x540x1')
end
pause
end
end
end
toc
close(conn)
2 comentarios
Jan
el 20 de Nov. de 2016
What does "Due to the use of sprintf and a matrix containing singles and doubles" mean? Matrices cannot contain values of different type.
Respuestas (1)
Sid Jhaveri
el 5 de Dic. de 2016
1) I believe that the HDF5 file that you are reading contains singles and you would like to convert it into hexadecimal values. You can do so by using “ num2hex ” function. Thus, instead of the converting your singles into doubles, convert it into hexadecimal values.
For example, instead of using,
evap= double(h5read('path','/data',cutstart,cutlength));
use,
evap= num2hex(h5read('path','/data',cutstart,cutlength));
2) You can also try to convert the double precision values into single precision values by using “ single ” function. This way, all the numeric values in your code will be single precision.
I hope is helps.
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