dx-doc 1:4.4.4-7 / usr / share / doc / dx / help / dxall792

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#!N 
#!N 
 #!Rcolor Color #!N #!N Category #!N #!N  #!Lcattrn,dxall763 h Transformation  #!EL  #!N #!N Function 
#!N #!N Colors a field. #!N #!N Syntax #!CForestGreen #!N #!N 
 #!F-adobe-courier-bold-r-normal--18*    #!F-adobe-times-bold-r-normal--18*   #!N colored #!EF = Color(  #!F-adobe-times-bold-r-normal--18*   input, color, opacity, 
component, delayed #!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 input TAB field TAB none TAB field 
to be colored #!N TAB color TAB field or vector or 
string TAB no color added TAB RGB color #!N TAB opacity 
TAB field or scalar TAB input dependent TAB opacity #!N TAB 
component TAB string TAB "colors" TAB component to be colored #!N 
TAB delayed TAB flag TAB 0 TAB 0: apply maps #!N 
TAB - TAB - TAB - TAB 1: delay applying color 
and #!N TAB - TAB - TAB - TAB opacity maps 
(byte data #!N TAB - TAB - TAB - TAB only) 
#!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 colored TAB color field TAB color-mapped input field 
#!N TAB - TAB - TAB #!EF #!N #!N Functional Details 
#!N #!N This module adds a specified color to a specified 
input object. #!N #!I0 #!N #!N #!I0 #!N  #!F-adobe-times-bold-r-normal--18*    #!F-adobe-times-bold-r-normal--18*   input 
#!EF #!EF #!I50 #!N is the field to be colored. #!N 
#!I0 #!N  #!F-adobe-times-bold-r-normal--18*    #!F-adobe-times-bold-r-normal--18*   color #!EF #!EF #!I50 #!N specifies how 
the input field is to be colored. The specification can be 
the vector value of an RGB color, a string, or a 
color map. #!N #!N If  #!F-adobe-times-bold-r-normal--18*   color #!EF is an RGB 
color, the value should be in the range of 0-1 (but 
see  #!Lcvolrnd,dxall820 h Coloring Objects for Volume Rendering  #!EL  ). The Convert module can convert HSV (hue, saturation, 
and value) colors to RGB. #!N #!N If  #!F-adobe-times-bold-r-normal--18*   color #!EF 
is a string, that string should come from a lookup table, 
which can be specified by setting the DXCOLORS environment variable or 
by using the -colors flag with the dx command. If no 
table is specified, Data Explorer will search (in the order shown) 
for one of the following: #!N #!I0 #!N  #!F-adobe-times-medium-r-normal--18*   #!N #!N 
#!I30 #!N 1. the file colors.txt in DXROOT/lib #!N #!I30 #!N 
2. the same file in  #!F-adobe-times-bold-r-normal--18*   /usr/lpp/dx/lib #!EF (if this was 
not the setting for DXROOT). Note that the colors in this 
file correspond to the X Window System** color list, except that 
the Data Explorer colors are squared first (see  #!Lintcols,dxall747 h Data Explorer Colors  #!EL  in IBM 
Visualization Data Explorer User's Guide). #!N #!I0 #!N #!EF #!N When 
entering the names of colors, note that the module: #!N #!I0 
#!N  #!F-adobe-times-medium-r-normal--18*   #!N #!N #!I30 #!N o accepts spaces in names. 
#!N #!I30 #!N o ignores capitalization. #!N #!I30 #!N o accepts 
the spellings  #!F-adobe-times-medium-i-normal--18*   gray #!EF and  #!F-adobe-times-medium-i-normal--18*   grey #!EF . #!N 
#!I0 #!N #!EF #!N #!N #!N If  #!F-adobe-times-bold-r-normal--18*   color #!EF is 
a color map it can be the output of the Colormap 
Editor (the first output) or an imported color map. Note also 
that if this parameter is a color map (as opposed to 
a single color), then the  #!F-adobe-times-bold-r-normal--18*   input #!EF parameter must contain 
a "data" component; if the "data" component consists of vector data, 
the color and opacity mapping are based on the magnitude of 
the data. If this parameter is an imported .cm file (see 
 #!Limport,dxall871 h Import  #!EL  ), the color-map part of the color-opacity map is extracted 
and used. #!N #!N Omitting the color specification allows you to 
change the opacity of an object without modifying its color (see 
 #!Lwfcmap,dxall792 s WFCMAP  #!EL  for a description of a color map). #!N #!N A 
well-formed color map should contain a 1-dimensional "positions"  #!Rwfcmap component and 
a 3-dimensional "data" component. As with any map in Data Explorer, 
the "positions" component represents the domain in which to look up 
values, and the "data" component represents the range, that is, the 
values which are associated with items in the "positions" component. #!N 
#!N Color maps can specify either smoothly varying colors or constant 
colors across a set of ranges of data values. If the 
color map has position-dependent data, then linear interpolation will be used 
to derive colors for data values in the data field between 
those given in the "positions" component of the map (see  #!Lcolmap114,dxall792 f Figure 114  #!EL  
). #!Cbrown #!N  #!F-adobe-times-medium-r-normal--18*    #!Rcolmap114 #!N Figure 114. Position-dependent colormaps. In 
this figure a diagram of a data field is shown. One 
of the data values, 3.5, has been indicated. The field structure 
is also shown, with "positions," "data," and "connections" components. When a 
color map is applied to this field using the Color module, 
the data value 3.5 is used as a lookup value into 
the "positions" component of the color map. The color map has 
a "data" component which is dependent on (in a one-to-one correspondence 
with) the "positions" component. The color map contains colors for the 
value 3 (the RGB value [0 1 1], or cyan) and 
for the value 4 (the RGB value [0 0 0], or 
black). Data Explorer interpolates between these two colors to derive the 
color [0 .5 .5], or dark cyan, which is then placed 
in the "colors" component of the data field as the color 
corresponding to the data value 3.5. #!N Graphics omitted from Online 
Documentation. Please see the manual. #!N #!EF #!N #!EC If the 
colormap has connection-dependent data, then the color for any data value 
in the data field between two values in the "positions" component 
of the map will be constant (see  #!Lcolmap1115,dxall792 f Figure 115  #!EL  ). #!Cbrown #!N 
 #!F-adobe-times-medium-r-normal--18*    #!Rcolmap1115 #!N Figure 115. Connection-dependent colormaps. In this figure a 
diagram of a data field is shown. One of the data 
values, 3.5, has been indicated. The field structure is also shown, 
with "positions," "data," and "connections" components. When a color map is 
applied to this field using the Color module, the data value 
3.5 is used as a lookup value into the "positions" component 
of the color map. The color map has a "data" component 
which is dependent on (in a one-to-one correspondence with) the "connections" 
component. The color map contains colors for the range 1 to 
1.5 (the RGB value [1 1 0], or yellow), the range 
1.5 to 3 (the RGB value [0 1 1], or cyan) 
and for the range 3 to 4 (the RGB value [0 
0 1], or blue). Since 3.5 lies in the range 3 
to 4, Data Explorer looks up the color [0 0 1] 
and places it in the "colors" component of the data field 
as the color corresponding to the data value 3.5. #!N Graphics 
omitted from Online Documentation. Please see the manual. #!N #!EF #!N 
#!EC In either case, the "connections" component of the map should 
be a set of lines connecting the positions. #!N #!N The 
Colormap Editor puts out a well-formed colormap. The Construct module can 
also be used to create a color map. For example, you 
have 10 data values to which you want to apply particular 
colors. List those 10 data values as the first parameter to 
Construct. Then list the 10 colors (RGB vectors) as the last 
parameter to Construct. This will automatically create a position-dependent color map 
of the appropriate structure to use with the Color module. Alternatively, 
if you list only 9 colors (RGB vectors) as the last 
parameter to Construct, a connection-dependent color map will be created. #!N 
#!N For surfaces, RGB colors in a color map should range 
between 0 and 1. Compute can be used to convert colors 
from the range of 0 to 255 to the range 0 
to 1. To choose appropriate colors for volumes see  #!Lcvolrnd,dxall820 h Coloring Objects for Volume Rendering  #!EL  . 
Note that if you have an HSV (hue, saturation, and value) 
color map, it can be converted to an RGB (red, blue, 
green) color map using the Convert module. #!N #!I0 #!N  #!F-adobe-times-bold-r-normal--18*   
 #!F-adobe-times-bold-r-normal--18*   opacity #!EF #!EF #!I50 #!N can be a scalar value 
or a field specifying an opacity map. This map may be 
the output of the Colormap Editor (the second output) or an 
imported opacity map. If it is an imported .cm file (see 
 #!Limport,dxall871 h Import  #!EL  ), the opacity part of the color-opacity map will be 
extracted and used (see below for a description of an opacity 
map). #!N #!N The input color or opacity can also be 
groups of color or of opacity maps, as long as the 
hierarchy of the group matches that of  #!F-adobe-times-bold-r-normal--18*   input #!EF . 
#!N #!N For surfaces, the default value of  #!F-adobe-times-bold-r-normal--18*   opacity #!EF 
is 1.0; the valid range is 0-1. For volumes, the default 
value is 0.5. If the object to be colored is a 
volume with an aspect ratio much different from 1, it may 
appear dark from certain viewing directions. In that case, use the 
Compute module to multiply the contents of the data component of 
the opacity and color maps by a scale factor greater than 
1 before using them as an input to the Color module. 
(If you are using delayed colors, modify the "color multiplier" and 
"opacity multiplier" attributes. See the  #!F-adobe-times-bold-r-normal--18*   delayed #!EF parameter, described below.) 
#!N #!N A well-formed opacity map should contain a 1-dimensional "positions" 
component and a 1-dimensional "data" component representing opacities. For surfaces, valid 
opacities range between 0 (transparent) and 1 (opaque). To choose appropriate 
opacities for volumes see  #!Lcvolrnd,dxall820 h Coloring Objects for Volume Rendering  #!EL  . Just as with a color 
map, the "data" component may be either position-dependent or connection-dependent. An 
opacity map can be created either with the Colormap Editor or 
using the Construct module as described for color maps. #!N #!I0 
#!N  #!F-adobe-times-bold-r-normal--18*    #!F-adobe-times-bold-r-normal--18*   component #!EF #!EF #!I50 #!N specifies the component 
to which the module adds colors. The default is the "colors" 
component, which applies to both the front and the back of 
the object, but you can specify "front colors" or "back colors" 
instead. Either one, if present, takes precedence over the "colors" component. 
If you specify  #!F-adobe-times-bold-r-normal--18*   component #!EF as "colors," the module deletes 
any existing "front colors" or "back colors" components. Which faces are 
"front" and which faces are "back" depends on how "connections" component 
of the faces is defined (see  #!Lstancom,dxall201 h Standard Components  #!EL  in IBM Visualization Data 
Explorer User's Guide). #!N #!I0 #!N  #!F-adobe-times-bold-r-normal--18*    #!F-adobe-times-bold-r-normal--18*   delayed #!EF #!EF 
#!I50 #!N causes Color to create "delayed colors." This option is 
valid only for byte data. When  #!F-adobe-times-bold-r-normal--18*   delayed #!EF = 1: 
#!N #!I0 #!N  #!F-adobe-times-medium-r-normal--18*   #!N #!N #!I30 #!N o the "colors" 
component is a copy of the "data" component, and a "color 
map" component is created (i.e., a color lookup table with 256 
entries representing the appropriate color for each of the 256 possible 
data values). #!N #!I30 #!N o (if  #!F-adobe-times-bold-r-normal--18*   opacity #!EF has 
been specified) the "opacities" component is a copy of the "data" 
component, and an opacity map with 256 entries is created. #!N 
#!I30 #!N o the module adds a "direct color map" attribute 
to the output object (see  #!Ludcmps,dxall813 h Using Direct Color Maps  #!EL  ). #!N #!I0 #!N #!EF 
#!N #!I0 #!N #!N #!N #!N Components #!N #!N Adds a 
"colors" component. An "opacities" component is added if  #!F-adobe-times-bold-r-normal--18*   opacity #!EF 
is less than 1 or the input data is a volume. 
If  #!F-adobe-times-bold-r-normal--18*   delayed #!EF = 1, the "colors" component is a 
copy of the "data" component and a "color map" component is 
created. Likewise, an "opacity map" component is created if  #!F-adobe-times-bold-r-normal--18*   opacity 
#!EF is less than one or the input is a volume. 
#!N #!N Example Visual Programs #!N #!N Nearly every example visual 
program uses Color, including: #!CForestGreen #!N #!N  #!F-adobe-courier-bold-r-normal--18*   #!N AlternateVisualizations.net #!N 
Sealevel.net #!N UsingColormaps.net #!N SIMPLE/Color #!EF #!N #!N #!EC #!N #!N 
See Also #!N #!N  #!Lautocol,dxall772 h AutoColor  #!EL  ,  #!Lcaption,dxall781 h Caption  #!EL  ,  #!Lconvert,dxall799 h Convert  #!EL  ,  #!Lmap,dxall891 h Map  #!EL  
#!N #!N #!N  #!F-adobe-times-medium-i-normal--18*   Next Topic #!EF #!N #!N  #!Lcolorba,dxall793 h ColorBar  #!EL  #!N 
 #!F-adobe-times-medium-i-normal--18*   #!N