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DDESIGN procedure

Plots the plan of an experimental design (K.E. Bicknell & R.W. Payne).


Y = variate Specifies the y position of the plots in standard coordinates 1 … number of rows of plots in the experiment (taking 1 as the top row of the window)
X = variate Specifies the x-coordinate of the plots in standard coordinates 1 … number of columns of experimental plots
TITLE = text Title for the plan
WINDOW = scalar Window number for the plan; default 3
KEYWINDOW = scalar Window number for the key; default 0
SCREEN = string token Whether to clear the screen before plotting (clear, keep); default clea
KEYDESCRIPTION = text Overall description for the key; default *
ENDACTION = string token Action to be taken after completing the plot (continue, pause); default * uses the setting from the last DEVICE statement
CHARACTERS = scalar Sets a limit on the length of each factor label; default * i.e. none
SIZE = scalar Provides a multiplier by which to scale the sizes of the factor labels on the plan


FACTOR = factors Factors to be listed on the plan and to define the layout (the procedure determines the style of line to divide each pair of plots in the design from the grid pen of the first factor in the list with which they have different levels); default * forms the list from first the factors specified by a preceding BLOCKSTRUCTURE statement, and then those specified by a preceding TREATMENTSTRUCTURE statement
PEN = scalars Pen to be used to write the levels of each factor on the plan (if PEN=0 the levels of that factor are not included); default 1 if the FACTOR parameter is specified, otherwise 0 for block factors and 1 for treatment factors
PENGRID = scalars Pens to be used to draw the boundaries between the plots in the design (according to the first FACTOR with which they have different levels but ignoring factors with PENGRID=0); default 1,2…
LABELS = texts Labels to be used for each factor if its own levels or labels are inappropriate


DDESIGN uses high-resolution graphics to produce a plan of an experimental design. The plots in the design are assumed to be arranged on a rectangular grid. The rows of the plots are assumed to run from 1 (at the top of the graph) upwards and are specified by a variate supplied by the Y option. The columns (again running from 1 upwards) specified by a variate supplied by the X option. If either Y or X is not specified, DDESIGN will generate values automatically according to the factors in the design.

The TITLE, WINDOW, KEYWINDOW, SCREEN, KEYDESCRIPTION and ENDACTION options operate as usual in high-resolution graphics. The CHARACTERS option allows a limit to be set on the length of each factor label when written on the plan, and the SIZE option allows the size of the plotted factor labels to be scaled (using the SIZE parameter of the PEN directive).

The factors involved in the experiment can be listed using the FACTOR parameter. If this is omitted DDESIGN forms the list firstly from the factors in the previous BLOCKSTRUCTURE statement (or a “units” factor if there was none), and then from the factors (if any) in the previous TREATMENTSTRUCTURE statement.

These factors are then used to draw the plan and to label the plots in the design. The PEN parameter allows the levels or labels of the factors to be drawn using different pens (and thus, for example, in different colours). If the pen for any factor is defined as zero, its levels/labels are not included. However, it can still be used to determine the lines drawn to delimit the plots. For these lines, DDESIGN considers each pair of adjacent plots and checks through the list of factors to find the first one for which they have different levels. It then uses the grid pen (defined by the PENGRID parameter) to draw the dividing line. If the grid pen of any factor is zero, it is ignored.

This makes it very easy to achieve the usual style of plan in which stronger lines are used for example to indicate the boundaries between different blocks than between the plots within blocks. For example, the parameter settings to draw a randomized block design with a single treatment factor Treat in this way would be

FACTOR=Block,Plots,Treat; PEN=1; PENGRID=1,2,0

if all the factors are to have their levels listed within the plots, or

FACTOR=Block,Plots,Treat; PEN=0,0,1; PENGRID=1,2,0

if only Treat is to be listed. Note that, as each pair of plots will have different levels of either Block or Plot (or both), the PENGRID specified here for Treat is irrelevant.

If a plot has no neighbour in some direction, DDESIGN will check the next but one plot; if this too is not used in the design, the grid pen of the first FACTOR is used to mark the boundary.

The final parameter, LABELS, allows alternative labels to be specified for each factor if the existing ones are inappropriate.




DDESIGN makes use only of standard Genstat facilities for manipulation and plotting.

Action with RESTRICT

If any of the factors or X or Y is restricted, only the unrestricted plots are displayed.

See also


Commands for: Design of experiments.


        !t('1) Randomized block design in 4 blocks each of 8 plots',\
        'all on a regular grid.'); STYLE=meta,plain
FACTOR  [LEVELS=4] Blocks; VALUES=!(8(1...4))
&       [LEVELS=8] Plots; VALUES=!((1...8)4)
&       [LEVELS=8] Treat; VALUES=!(1...8,1...4,8...5,5...8,4...1,8...1)
VARIATE X,Y; VALUES=!((1...4)8),!(4(1...8))
DDESIGN [Y=Y; X=X] Blocks,Plots,Treat; PENGRID=1...3;\ 
CAPTION 'Plots on an irregular grid, and with a gap in one block.'
VARIATE X,Y; VALUES=!((1,2)4, (3,4,6,7)2, (1...4)2, 6,6,(4,5,6)2),\
                    !(2(1...4), 4(2,3), 4(6,7), 9,10,3(11,12))
DDESIGN [Y=Y; X=X] Blocks,Plots,Treat; LABELS=*,*,!t(a,b,c,d,e,f,g,h)
CAPTION  !t('2) Split plot design (Yates,F: The Design and Analysis',\
         'of Factorial Experiments, Commonwealth Bureau of Soils,',\
         'Tech. Comm. 35 p.74)')
&        [LEVELS=3] Wplot
&        [LEVELS=4] Subplot
GENERATE Block,Wplot,Subplot
FACTOR   [NVAL=72; LABELS=!T('0 cwt','0.2 cwt','0.4 cwt','0.6 cwt')] Nitrogen
&        [NVAL=72; LABELS=!T(Victory,'Golden rain',Marvellous)]      Variety
READ     [SERIAL=yes] Nitrogen,Variety
 4 3 2 1 1 2 4 3 1 2 3 4 3 1 2 4 4 1 2 3 2 1 3 4
 2 3 4 1 4 2 3 1 1 4 2 3 3 4 1 2 1 3 4 2 2 3 4 1
 4 1 3 2 3 4 1 2 3 4 2 1 3 1 4 2 4 3 1 2 1 2 3 4 :
 3 3 3 3 1 1 1 1 2 2 2 2 3 3 3 3 1 1 1 1 2 2 2 2
 2 2 2 2 3 3 3 3 1 1 1 1 3 3 3 3 2 2 2 2 1 1 1 1
 2 2 2 2 1 1 1 1 3 3 3 3 1 1 1 1 2 2 2 2 3 3 3 3 :
BLOCKSTRUCTURE Block/Wplot/Subplot
Updated on March 8, 2019

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