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Controlling Candidate Points
The rowexch
function generates a candidate set of possible design points, and then uses a D-optimal algorithm to select a design from those points. It does this by invoking the candgen
and candexch
functions. If you need to supply your own candidate set, or if you need to modify the one that the candgen
function provides, then you may prefer to call these functions separately.
This example creates a design that represents proportions of a mixture, so the sum of the proportions cannot exceed 1.
% Generate a matrix of (x,y) values with x+y<=1 [x,y]=meshgrid(0:.1:1); xy = [x(:) y(:)]; xy = xy(sum(xy,2)<=1,:); % Compute quadratic model terms for these points. f = x2fx(xy,'q'); % Generate a 10-point design and display it r=candexch(f,10); xy(r,:) ans = 0 0 0 1.0000 1.0000 0 0 0.5000 0.5000 0 0 1.0000 1.0000 0 0.5000 0.5000 0.5000 0 0.5000 0.5000
![]() | Designing Experiments with Uncontrolled Inputs | Including Categorical Factors | ![]() |