#!F-adobe-helvetica-medium-r-normal--18*
#!N 
#!CSeaGreen 
#!N  #!Rtcmpmod Modules: Using Compute #!N #!EC #!N #!N  #!F-adobe-times-bold-r-normal--18*   Compute 
#!EF is a general purpose module for performing algebraic, trigonometric, and 
logical operations on data. It can also extract components from vectors, 
create vectors from scalar components, and cast between different data types. 
#!N #!I0 #!N  #!F-adobe-times-medium-r-normal--18*   #!N #!N #!I30 #!N 1. Open and 
execute visual program .../Compute.net. The image represents wind velocity over the 
surface of the earth. Color values are based on the magnitude 
of the wind velocity, and the small black squares and rectangles 
represent missing data. #!N #!I30 #!N 2. Disconnect  #!F-adobe-times-bold-r-normal--18*   Include #!EF 
from  #!F-adobe-times-bold-r-normal--18*   AutoColor #!EF and connect the output of  #!F-adobe-times-bold-r-normal--18*   Compute 
#!EF to  #!F-adobe-times-bold-r-normal--18*   AutoColor #!EF instead. #!N #!I30 #!N 3. Execute 
the visual program. Now the colors are based on the absolute 
value of the x-component of the wind velocity. #!N #!I30 #!N 
4. Double click on the  #!F-adobe-times-bold-r-normal--18*   Compute #!EF icon to open 
the configuration dialog box. In this example the module has a 
single input (  #!F-adobe-times-bold-r-normal--18*   wind #!EF ), and the operation to 
be performed is to determine the absolute value of its x-component. 
#!N #!I30 #!N 5. Change "abs(wind.x)" in the  #!F-adobe-times-bold-r-normal--18*   Expression #!EF 
field to "abs(wind.y)." and reexecute the visual program. The image changes 
accordingly. #!N #!I0 #!N #!EF #!N Note:  #!F-adobe-times-bold-r-normal--18*   Compute #!EF is 
not limited to a single input, and input tabs can be 
added with the  #!F-adobe-times-bold-r-normal--18*   Add Input Tab #!EF function in the 
 #!F-adobe-times-bold-r-normal--18*   Edit #!EF pull-down menu (see  #!Ltadts,dxall58 h Adding Input Tabs to Tool Icons  #!EL  ). By default the 
inputs to  #!F-adobe-times-bold-r-normal--18*   Compute #!EF are labeled a, b, c,..., but 
you can rename them. #!N #!N It is also possible to 
use  #!F-adobe-times-bold-r-normal--18*   Compute #!EF on components other than  #!F-adobe-times-bold-r-normal--18*   data #!EF 
. For example, suppose you wanted to display a regular 2-D 
grid of latitude and longitude on a spherical surface. You could 
use  #!F-adobe-times-bold-r-normal--18*   Compute #!EF to convert the x,y positions of latitude 
and longitude to x, y, and z positions of a spherical 
surface. For an example, open and execute visual program .../WarpedGrid.net, which 
generates two entirely different objects (in separate Image windows) from the 
same data. #!N #!N See Compute in IBM Visualization Data Explorer 
User's Reference. #!N #!N #!N  #!F-adobe-times-medium-i-normal--18*   Next Topic #!EF #!N #!N 
 #!Ltmappng,dxall82 h Modules: Using Map  #!EL  #!N  #!F-adobe-times-medium-i-normal--18*   #!N 
