Set the Attributes of SCANs

These are the items which can be set for SCANs:

/at=(nrow, ncol, row[, col])

A very efficient way to specify the viewport of a SCAN. The meaning of the AT qualifier is: If the graphical window were divided into a grid of nrow rows and ncol column, put the scan into the position (row, col).

If row is omitted, col may run from 1 to ncol$*$nrow.

Here are two examples to illustrate the function of the /AT qualifier. Both commands are equivalent

SPECTRA> set bpu1/v2
SPECTRA> set bpu1/at=(2,2,1,1)

This example is not very impressive because no keystrokes are saved. But if you have to display several scans, you can place them on the screen with such a loop (output in section 15.3.69):

!
! This command file displays the usage of the /at= qualifier
! e.g.:
!
!   SPECTRA> run at_example.gra 3 4
!
 var ncol nrow

 if !gra_status()
   end
 endif

 del *.*

 for( i=1; i < (ncol*nrow + 1); i = i + 1)
  create/notext "test_"i 0 10 100
  set "test_"i/at=(ncol,nrow,i)
 endfor

 display
 post/eps/col/nocon at_example.ps

/col$*$our=int_expr

The colour of the output primitive. The table 15.3.69 contains the colour codes. An example of how the colour opaque is used can be found in 15.3.69 (code) and 15.3.69 (output).

/com_n=text_expr

The comment lines: $n$ varies from 1 to 10. The first comment line can also be accessed by /com. During change only the first comment line is visible, the others can be inspected by show id.

/date1=text_expr

Sets date1, it is displayed during change mode.

/date2=text_expr

Sets date2, it is displayed by show id.

/doty=1

The x-values are considered as date-of-the-year values. The big tic marks get date strings. Only three big tics are displayed.

/li$*$ne_at_0=int_expr

If this flag is set, SPECTRA draws a line at y=y_shift.

/n_b$*$in=int_expr

Average groups of n_bin points. In contrast to the combin command, this attribute has only an effect on the display. It does not change the data.

/par

So far used only for the line-marker primitive. While /type selects the line type, /par determines the marker type.

/pa$*$irs

/nopa$*$irs

A flag that determines, if a SCAN is interpreted as a series of start and end points. Used for error bars.

/pri$*$mitive=int_expr

0 - Line
1 - Marker
2 - Histogram
3 - Filled histogram
4 - Filled line
5 - Line and marker

In case '5' is selected, SPECTRA draws markers on a line. The line type is determined by /type the marker type by bf /par.

A figure that demonstrates some primitive types can be found in section 15.3.69. Here is the code that created it.

  delete *.*

  crea/notex tn 0 10 60
  calc tn = tan(tn) + 40
  
  deact tn

  cop tn tn1
  set tn1/prim=0/v11/col=1
  create/text/string="Line (0), Type 1"/x=0.05/y=0.8 tn1

  cop tn tn2
  set tn2/prim=0/v12/type=4/col=1
  create/text/string="Line (0), Type 4"/x=0.05/y=0.8 tn2

  cop tn tn3
  set tn3/prim=1/v13/col=2/type=1
  create/text/string="Marker (1), Type 1"/x=0.05/y=0.8 tn3

  cop tn tn4
  set tn4/prim=1/v14/col=2/type=4
  create/text/string="Marker (1), Type 4"/x=0.05/y=0.8 tn4

  cop tn tn5
  set tn5/prim=2/v15/col=3/type=1
  create/text/string="Hist (2), Type 1"/x=0.05/y=0.8 tn5

  cop tn tn6
  set tn6/prim=3/v16/col=3/type=1
  create/text/string="Hist Area (3), Type 1"/x=0.05/y=0.8 tn6

  cop tn tn7
  set tn7/prim=4/v17/col=4/type=1
  create/text/string="Line Area (4), Type 1"/x=0.05/y=0.8 tn7
!
! par selects the marker type for line-marker
!
  cop tn tn8
  set tn8/prim=5/v18/col=4/type=1/par=4
  create/text/string="Line-marker (5), Type 1, Par 4"/x=0.05/y=0.8 tn8
 
!
! negative major tic mark factors suppress 
! the tic mark numbers
!
  set */x_maj=-4/y_maj=-4

  display
  post/eps/col/nocon

/scale$*$factor=float_expr

The autoscale command sets the y-window limit to y_max = scalefactor $*$ max(y) and likewise y_min. Y_min will not be set to negative numbers this way.

/si$*$ze=float_expr

Line width or marker size.

/ty$*$pr=int_expr

Primitive type. See the tables in the sections 15.3.69 and 15.11 for an explanation of the code.

/x_a$*$xis=text_expr

/y_a$*$xis=text_expr

Sets the axis description string. These strings are copied to TEXT GQEs when a SCAN is created.

/x_ma$*$x=float_expr

/x_mi$*$n=float_expr

/y_ma$*$x=float_expr

/y_mi$*$n=float_expr

The window limits. They determine how a SCAN is mapped into the viewport. The autoscale command sets the window limits to default values.

/x_max_v$*$iew=float_expr

/x_min_v$*$iew=float_expr

/y_max_v$*$iew=float_expr

/y_min_v$*$iew=float_expr

The viewport limits. The viewport is the portion of the workstation viewport where the window is mapped. It can also be changed by the locator command.

The size of the viewport is specified in graphical coordinates, from 0 to 1.

/v0

Instead of specifying the viewport limits, you may choose one of the predefined viewports:

/v0 default viewport

/v1 upper left corner
/v2 upper right corner
/v3 lower left corner
/v4 lower right corner

/v5 upper half
/v6 lower half
/v7 left half
/v8 left half

The predefined viewports are displayed in 15.3.69, .

/x_f$*$ormat=text_expr

/y_f$*$ormat=text_expr

The output format for the numbers at the major tic marks. If it is set to AUTO, SPECTRA chooses its own format.

The format specification has to be done according to the syntax of the language C (e.g.: Floating point representation with a mantissa of four digits: "%7.4f", or an exponential representation, again with a mantissa of four digits: "%7.4e". Integer valued numbers are printed with : "%d".)

/x_l$*$og=int_expr

/y_l$*$og=int_expr

The scale type.

0 - Linear 1 - Logarithmic

Logarithmic scales should have maj_tic = 9 and the tic distance set to the lower window limit.

/x_maj=int_expr

/y_maj=int_expr

Every x_majth tic mark is a major tic mark. If it is less than 0, no numbers are plotted at the major tic marks.

/x_maj_o$*$ff=int_expr

/y_maj_o$*$ff=int_expr

The offset for the major tic marks, measured in units of tics.

Example: Suppose there is data that varies from 880 to 2000. The tic marks should start at 900, the first big tic mark at 1000. This is accomplished by setting x_tic=100, x_tic_off=20, x_maj_off=1.

/x_s$*$hift=float_expr

/y_s$*$hift=float_expr

Shifts the data. The amount of the shift has to be supplied in physical coordinates.

/x_tic=float_expr

/y_tic=float_expr

The tic distance, measured in units of world coordinates.

/x_tic_o$*$ff=float_expr

/y_tic_o$*$ff=float_expr

The tic distance offset, measured in units of world coordinates.

e.g.:

SPECTRA> set bpu1/y_log=1/y_maj=9/y_min=0.1/y_tic=0.1

Figure 15.2: Example: Lines, markers, etc., code in sec.

Figure 15.3: Setting Viewports with "set /at=”, code in sec. 15.3.69

Figure 15.4: Viewports V0, V1, ... V4, code in sec. 6.1

Figure 15.5: Viewports V5 - V6, code in sec. 6.1

Figure 15.6: Viewports V7 - V8, code in sec. 6.1