#!F-adobe-helvetica-medium-r-normal--18*
#!N 
#!N  #!Rimport 
Import #!N #!N Category #!N #!N  #!Lcatiae,dxall756 h Import and Export  #!EL  #!N #!N Function #!N 
#!N Reads an external data file. #!N #!N Syntax #!CForestGreen #!N 
#!N  #!F-adobe-courier-bold-r-normal--18*   #!N  #!F-adobe-times-bold-r-normal--18*   data #!EF = Import(  #!F-adobe-times-bold-r-normal--18*   name, variable, 
format, start, end, delta #!EF ); #!EF #!N #!N #!EC #!N 
#!N Inputs #!T,1,91,276,461,646  #!F-adobe-times-medium-r-normal--14*    #!F-adobe-times-bold-r-normal--18*   #!N TAB Name TAB Type TAB 
Default TAB Description #!EF #!N TAB name TAB string TAB none 
TAB name of file containing data to be #!N TAB - 
TAB - TAB - TAB read, or "!command" #!N TAB variable 
TAB string or string list TAB format dependent TAB variable to 
be read #!N TAB format TAB string TAB file extension or 
content TAB "dx," "general," "netcdf," "CDF," #!N TAB - TAB - 
TAB - TAB "hdf," "cm" #!N TAB start TAB integer TAB 
first frame TAB first data frame to be imported #!N TAB 
end TAB integer TAB last frame TAB last data frame to 
be imported #!N TAB delta TAB integer TAB 1 TAB increment 
between frames #!N TAB - TAB - TAB - TAB #!EF 
#!N #!N Outputs #!T,1,161,321,646  #!F-adobe-times-medium-r-normal--14*    #!F-adobe-times-bold-r-normal--18*   #!N TAB Name TAB Type 
TAB Description #!EF #!N TAB data TAB object TAB object containing 
requested variables #!N TAB - TAB - TAB #!EF #!N #!N 
Functional Details #!N #!N From an external data file this modules 
creates Data Explorer objects that can be processed by other modules. 
#!N #!I0 #!N #!N #!I0 #!N  #!F-adobe-times-bold-r-normal--18*    #!F-adobe-times-bold-r-normal--18*   name #!EF #!EF 
#!I50 #!N is the name of the data file being imported. 
If the parameter specifies an absolute path name, the system attempts 
to open the file. Otherwise, it first searches the current directory 
(i.e., the directory from which Data Explorer was invoked) and then, 
if necessary, the directories specified by the environment variable DXDATA (see 
 #!Lenvvar,dxall684 h Environment Variables  #!EL  in IBM Visualization Data Explorer User's Guide). Note: This parameter 
can also specify an external filter (see  #!Lextflt,dxall871 s External filters  #!EL  ). #!N #!N 
If  #!F-adobe-times-bold-r-normal--18*   name #!EF contains a series, the parameters  #!F-adobe-times-bold-r-normal--18*   start 
#!EF ,  #!F-adobe-times-bold-r-normal--18*   end #!EF , and  #!F-adobe-times-bold-r-normal--18*   delta #!EF can 
be used to import a portion of the data (see parameter 
descriptions below). #!N #!I0 #!N  #!F-adobe-times-bold-r-normal--18*    #!F-adobe-times-bold-r-normal--18*   variable #!EF #!EF #!I50 
#!N specifies the variable(s) to be imported. #!N #!I0 #!N  #!F-adobe-times-bold-r-normal--18*   
 #!F-adobe-times-bold-r-normal--18*   format #!EF #!EF #!I50 #!N specifies the format of the 
data to be imported. Valid format names are: "dx," "general," "netcdf," 
"CDF," "hdf," and "cm." These keywords can also be used as 
extensions on file names. #!N #!I0 #!N  #!F-adobe-times-bold-r-normal--18*    #!F-adobe-times-bold-r-normal--18*   start #!EF 
 #!F-adobe-times-medium-r-normal--18*   and #!EF #!EF  #!F-adobe-times-bold-r-normal--18*   end #!EF #!I50 #!N specify the 
first and last data frame to be imported from a data 
file containing a series. #!N #!I0 #!N  #!F-adobe-times-bold-r-normal--18*    #!F-adobe-times-bold-r-normal--18*   delta #!EF 
#!EF #!I50 #!N specifies the increment in counting the data frames 
in the range from  #!F-adobe-times-bold-r-normal--18*   start #!EF to  #!F-adobe-times-bold-r-normal--18*   end #!EF 
. For example, if the first and last frames are 10 
and 20 respectively, and  #!F-adobe-times-bold-r-normal--18*   delta #!EF = 2, the output 
 #!F-adobe-times-bold-r-normal--18*   data #!EF is a series group with six members (frames 
10, 12, 14,...). #!I0 #!N #!N #!CIndianRed #!N #!N #!N  #!F-adobe-times-bold-r-normal--18*   
For Future Reference #!N #!N If the data set being imported 
is changed (e.g., by editing) during a Data Explorer session, and 
if the cache is enabled (the default condition), it may be 
necessary to reinitialize the Data Explorer executive to access the new 
data. To do so, select  #!F-adobe-times-bold-r-normal--18*   Reset Server #!EF in the 
 #!F-adobe-times-bold-r-normal--18*   Connections #!EF pull-down menu of the VPE window. #!N #!N 
Resetting the server flushes the executive cache. The next time the 
visual program is invoked, the entire network executes (not just the 
portions affected by changes) and Import will reaccess the data set. 
#!N #!N Specifying that the module's output not be cached has 
the same effect. Select the appropriate option in: #!N #!I0 #!N 
 #!F-adobe-times-medium-r-normal--18*   #!N #!N #!I30 #!N o the "Cache" option menu of 
the module's configuration dialog box,  #!F-adobe-times-medium-i-normal--18*   or #!EF #!N #!I30 #!N 
o the "Set Output Cacheability" option menu in the  #!F-adobe-times-bold-r-normal--18*   Edit 
#!EF pull-down menu. #!N #!N Note that it may be necessary 
to apply the same restriction to any module downstream from Import. 
#!N #!N To specify that  #!F-adobe-times-medium-i-normal--18*   no #!EF outputs are to 
be cached, use the  #!F-adobe-times-bold-r-normal--18*   -cache off #!EF option when starting 
Data Explorer. #!N #!I0 #!N #!EF #!N #!N #!N #!EC #!N 
#!N  #!F-adobe-times-bold-r-normal--18*   Data Explorer format files. #!EF A Data Explorer data 
file consists of one or more header and data sections that 
describe the structure and values of user data. The header section 
is a text description of one or more Data Explorer objects, 
and the data section is either a text or binary representation 
of the data values. #!N #!N If  #!F-adobe-times-bold-r-normal--18*   variable #!EF specifies 
more than one object, the module creates a group and each 
object is added to the group by name. If  #!F-adobe-times-bold-r-normal--18*   variable 
#!EF is not specified, the default object is imported. This object 
can be specified with the  #!F-adobe-times-bold-r-normal--18*   default #!EF keyword in the 
Data Explorer file format (see  #!Ledf,dxall623 h Data Explorer Native Files  #!EL  in IBM Visualization Data Explorer 
User's Guide). If it is not specified, the default object is 
the last object defined in the data file. #!N #!N Any 
Data Explorer object in a Data Explorer data file can be 
specified for import, including Lights, Cameras, and Transforms, as well as 
more common objects such as Series, Groups, and Fields. The data 
can be in a separate file from the header, and header 
and data sections can be interspersed. And the data can be 
specified in a variety of formats (see see  #!Ledf,dxall623 h Data Explorer Native Files  #!EL  in IBM 
Visualization Data Explorer User's Guide). #!N #!N  #!F-adobe-times-bold-r-normal--18*   General array importer 
files. #!EF You can use the general format described in  #!Lgai,dxall110 h General Array Importer  #!EL  
in IBM Visualization Data Explorer QuickStart Guide to import data from 
various file formats and convert the data to objects. This format 
allows you to describe the structure of your data so that 
Data Explorer can create Data Explorer objects from it. If you 
do not specify a variable, then all variables are imported. #!N 
#!N Normally, the  #!F-adobe-times-bold-r-normal--18*   name #!EF parameter in this case is 
the general array header file. However, the  #!F-adobe-times-bold-r-normal--18*   name #!EF parameter 
can be the data file if the extended form of the 
 #!F-adobe-times-bold-r-normal--18*   format #!EF parameter includes the header file as a template. 
The  #!F-adobe-times-bold-r-normal--18*   format #!EF parameter can also include any set of 
keyword-value pairs as a comma-separated list. The specified values are used 
instead of those in the header file. This format is useful 
for data files with similar header files where only the size 
of the data changes. An example for the  #!F-adobe-times-bold-r-normal--18*   grid #!EF 
keyword is: #!N #!N  #!F-adobe-times-bold-r-normal--18*   format #!EF ="general, template=headerfile, grid=num[x] x 
num[y] x num[z] ..." #!N #!N An example parameter for the 
 #!F-adobe-times-bold-r-normal--18*   points #!EF keyword is: #!N #!N  #!F-adobe-times-bold-r-normal--18*   format #!EF = 
"general, template=headerfile, points=n" #!N #!N You may also omit template=headerfile if 
all the necessary information is specified by the keyword-value pairs. #!N 
#!N  #!F-adobe-times-bold-r-normal--18*   netCDF files. #!EF When the netCDF file is opened, 
variables matching the  #!F-adobe-times-bold-r-normal--18*   variable #!EF parameter are read in as 
field objects. If you give no field name, all fields are 
read in and placed as separate fields in a group. Each 
group member is named using the name of the field in 
the netCDF file. If more than one variable has the same 
field name, a composite field is created. #!N #!N You can 
import both regular and irregular data. If the data are regular, 
nonzero origins and non-unit spacing can be handled. You can also 
import scalar, vector, and tensor data. For irregular data, "positions" and 
"connections" are determined from information in the netCDF variable attributes associated 
with the field. Additional components can also be read in and 
added to the field, based on netCDF attribute information. #!N #!N 
For a detailed description of the attributes required in a netCDF 
file, and an example of the correct format, see  #!Lnetcdf,dxall665 h netCDF Files  #!EL  in 
IBM Visualization Data Explorer User's Guide. #!N #!N  #!F-adobe-times-bold-r-normal--18*   CDF files. 
#!EF When the CDF is opened, variables matching the "variable" parameter 
are read in as fields. If "variable" is not specified, then 
all variables are imported and placed as fields in a group. 
Each group member is named using the name of the field 
(CDF variable) in the CDF. If the CDF contains records, then 
variable(s) are imported as a series. Some CDF variables become the 
"positions" component of the field, while others become the "data" component 
of the field. For a series, the values of the record-varying 
variable become the "series positions" attribute(s). Variable and global attributes present 
in the CDF are imported as object attributes. Only CDF r-variables 
are supported. See IBM Visualization Data Explorer User's Guide for more 
information on importing data from a CDF. #!N #!N  #!F-adobe-times-bold-r-normal--18*   HDF 
files. #!EF Scientific DataSets are read in as fields. If there 
are more than one DataSet in the HDF file, you can 
specify the variable as a number corresponding to the position of 
the data set (0 corresponds to the first file). If no 
variable is specified, all fields are read in and placed as 
separate fields in a group. Each group member is named using 
the label (if it exists) from the HDF file. #!N #!N 
If scales are present, they are interpreted as "positions" with regular 
"connections." Otherwise, the positions are a regular grid with regular connections. 
For more information on HDF, see  #!Lhdf,dxall682 h HDF Files  #!EL  in IBM Visualization Data 
Explorer User's Guide. #!N #!N  #!F-adobe-times-bold-r-normal--18*   CM files. #!EF Import will 
import saved color-map files. (To save a color map explicitly as 
a separate  #!F-adobe-times-bold-r-normal--18*   .cm #!EF file, choose  #!F-adobe-times-bold-r-normal--18*   Save As... #!EF 
in the  #!F-adobe-times-bold-r-normal--18*   File #!EF menu of the ColorMap Editor.) #!N 
#!N The imported file will be a group containing the color 
map as the first field and the opacity map as the 
second field. (Alternatively, you can import just one of these maps 
by specifying the  #!F-adobe-times-bold-r-normal--18*   variable #!EF parameter to Import as "colormap" 
or "opacity" respectively.) #!N #!N The color map is a field 
with a 1-dimensional "positions" component (the data values) and a 3-dimensional 
"data" component (the colors). Similarly the opacity map is a field 
with a 1-dimensional "positions" component (the data values) and a 1-dimensional 
"data" component (the opacities). #!N #!N You can pass the imported 
color and opacity maps to (1) the  #!F-adobe-times-bold-r-normal--18*   color #!EF and 
 #!F-adobe-times-bold-r-normal--18*   opacity #!EF tabs of the Color module or (2) the 
 #!F-adobe-times-bold-r-normal--18*   color-map #!EF and  #!F-adobe-times-bold-r-normal--18*   opacity #!EF parameters of the Colormap 
tool. #!N #!N When a .cm file is imported, the result 
is not only information describing the color and opacity maps themselves, 
but also information specifically intended for the Colormap Editor regarding control 
points. Users are not expected to create their own .cm files 
(other than by writing them using the  #!F-adobe-times-bold-r-normal--18*   Save As #!EF 
command in the Colormap Editor), as the content of this file 
is not documented. However users can import any field which has 
the appropriate color or opacity map structure and use it as 
input to either the Color or the Colormap tools. For more 
information on the structure of color and opacity maps, see  #!Lcolor,dxall792 h Color  #!EL  
. #!N #!N  #!F-adobe-times-bold-r-normal--18*   External filters. #!EF  #!Rextflt If the first 
character of the  #!F-adobe-times-bold-r-normal--18*   name #!EF parameter is "!" (e.g., "!ext2dx 
mydata.ext mydata.dx"), the rest of the string following the exclamation point 
is interpreted as a shell command to be executed. The command 
should be the name of an external filter program with any 
required arguments. The filter program can be any  #!F-adobe-times-medium-i-normal--18*   user-supplied #!EF 
program that reads data from other file formats or generates data, 
but it must output "dx" or "general array" format as standard 
output. The Import module waits for the program to execute, reads 
the output of the program, and imports the objects with the 
same options as if reading directly from a file. #!N #!N 
Example Visual Programs #!N #!N Nearly every example visual program uses 
the Import module. Most import Data Explorer format files. Two example 
programs that import general array format files are: #!CForestGreen #!N #!N 
 #!F-adobe-courier-bold-r-normal--18*   #!N GeneralImport1.net #!N GeneralImport2.net #!EF #!N #!N #!EC #!N #!N 
An example program that uses the external filter option is: #!CForestGreen 
#!N #!N  #!F-adobe-courier-bold-r-normal--18*   #!N ImportExternalFilter.net #!EF #!N #!N #!EC #!N #!N 
An example program that uses the extended form of the  #!F-adobe-times-bold-r-normal--18*   
format #!EF parameter is: #!CForestGreen #!N #!N  #!F-adobe-courier-bold-r-normal--18*   #!N MRI_2.net #!EF 
#!N #!N #!EC #!N #!N See Also #!N #!N  #!Lexport,dxall844 h Export  #!EL  , 
 #!Lpartiti,dxall902 h Partition  #!EL  ,  #!Lreadima,dxall915 h ReadImage  #!EL  ,  #!Limpspsh,dxall872 h ImportSpreadsheet  #!EL  #!N #!N #!N  #!F-adobe-times-medium-i-normal--18*   Next Topic 
#!EF #!N #!N  #!Limpspsh,dxall872 h ImportSpreadsheet  #!EL  #!N  #!F-adobe-times-medium-i-normal--18*   #!N 
