1. PRECIS Hands-on Demo with IDV
PRECIS Reading Workshop, August 2009
© Crown copyright Met Office

2. Preparing data for visualization with IDV using PP utilities
See Worksheet 1: PP utilities section 1 example 6
1. List the 12 files containing monthly mean 1.5m temp for 1986
ls $ARCHIVEDIR/adeha/03236/*a.pmi6*
2. Concatenate the monthly data
cat $ARCHIVEDIR/adeha/03236/adehaa.pmi6* > monthlyTm1986.pp
3. Regrid monthlyTm1986.pp (or use the user interface)
ppregrid -d 0.5,0.5 -o monthlyTmreg.pp monthlyTm1986.pp
4. Convert data from PP to NetCDF
ppnc monthlyTmreg1986.pp monthlyTmreg1986.nc
5. Repeat steps 1 – 4 for precip (05216) replace Tm with Precip in the filenames above
© Crown copyright 2007

3. Data Chooser: Loading file into memory
Select the directory you want to poll in the “Look in” menu-> IDV
Specify the data type in the “Data Source Type” menu-> Grid files (Netcdf/Grib/….)
Select the file in the window below the “Look In” menu -> monthlyTmreg1986.nc
Press the “Add Source” button to load the datasets into the “Field Selector”
© Crown copyright 2007

4. Field Selector: Analysing and visualising
Select the display type -> Plan View> Color Filled Contour
Click on the “Create Display”
Click on the play button in the “animation panel”
Click on formulas
Select define a formula
Click on “Create Display”
Type “a ” and press “Enter”
Click “OK”
Select “Image” for display
Double-click on the legend > Color Table
Select Basic > Temperature
© Crown copyright 2007

5. Data Chooser: Loading file into memory
Select the directory you want to poll in the “Look in” menu-> IDV
Specify the data type in the “Data Source Type” menu-> Grid files (Netcdf/Grib/….)
Select the file in the window below the “Look In” menu -> monthlyPrecipreg1986.nc
Press the “Add Source” button to load the datasets into the “Field Selector”
© Crown copyright 2007

6. Field Selector: Analysing and visualising
Select the display type -> Plan View> Color Filled Contour
Click on the “Create Display”
Click on the play button in the “animation panel”
Click on “formulas”
Select “Define a formula”
Click on “Create Display”
Type “a*86400” and press “Enter”
Click “OK”
Select “Image” for display
Double-click on the legend > Color Table
Select Basic > Precip
© Crown copyright 2007