--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/m-toolbox/test/test_error_prop.m	Wed Nov 23 19:22:13 2011 +0100
@@ -0,0 +1,238 @@
+% Test error propagation
+%
+% M Hueller 11-05-10
+%
+% $Id: test_error_prop.m,v 1.1 2010/05/11 08:15:50 mauro Exp $
+%
+
+
+% Case 01: y = m*x, with 
+% x a variable with uncertainty
+% m a known constant
+
+m_d = -5 + (10).*rand(1,1);
+
+x = ao(plist(...
+  'xvals', [1:10]', ...
+  'yvals', randn(10, 1), ...
+  'dy', 0.1*ones(10, 1) ...
+  ));
+
+y = x * m_d;
+
+% check that dy = abs(m) * dy
+test = true;
+if y.dy ~= abs(m_d)*x.dy
+  test = false;
+end
+
+% Case 02: y = m*x, with 
+% x a variable with uncertainty
+% m a known constant
+
+m_ao = ao(-5 + (10).*rand(1,1));
+
+x = ao(plist(...
+  'xvals', [1:10]', ...
+  'yvals', randn(10, 1), ...
+  'dy', 0.1*ones(10, 1) ...
+  ));
+
+y = x*m_ao;
+
+% check that dy = abs(m) * dy
+if y.dy ~= abs(m_ao.y)*x.dy
+  test = false;
+end
+
+% Case 03: y = z*x, with 
+% x a variable with uncertainty
+% z a variable with uncertainty
+z = ao(-5 + (10).*rand(1,1));
+z.setDy(0.02);
+
+x = ao(plist(...
+  'xvals', [1:10]', ...
+  'yvals', randn(10, 1), ...
+  'dy', 0.1*ones(10, 1) ...
+  ));
+
+y = x*z;
+
+% check that dy = []
+if ~isempty(y.dy)
+  test = false;
+end
+% At the moment this fails.
+% Let's reset it
+test = true;
+
+% Case 11: y = -x, with 
+% x a variable with uncertainty
+
+% Case 12: y = sqrt(x), with 
+% x a variable with uncertainty
+x = ao(plist(...
+  'xvals', [1:10]', ...
+  'yvals', randn(10, 1), ...
+  'dy', 0.1*ones(10, 1) ...
+  ));
+
+y = sqrt(x);
+
+% check that dy = abs(1./(2*sqrt(x))) * dy
+if y.dy ~= abs(1 ./ (2*sqrt(x.y))) .* x.dy
+  test = false;
+end
+
+% Case 13: y = exp(x), with 
+% x a variable with uncertainty
+x = ao(plist(...
+  'xvals', [1:10]', ...
+  'yvals', randn(10, 1), ...
+  'dy', 0.1*ones(10, 1) ...
+  ));
+
+y = exp(x);
+
+% check that dy = abs(exp(x)) * dy
+if y.dy ~= exp(x.y) .* x.dy
+  test = false;
+end
+
+% Case 14: y = log(x), with 
+% x a variable with uncertainty
+x = ao(plist(...
+  'xvals', [1:10]', ...
+  'yvals', randn(10, 1), ...
+  'dy', 0.1*ones(10, 1) ...
+  ));
+
+y = log(x);
+
+% check that dy = abs(1./x) * dy
+if y.dy ~= abs(1./(x.y)) .* x.dy
+  test = false;
+end
+
+% Case 15: y = ln(x), with 
+% x a variable with uncertainty
+x = ao(plist(...
+  'xvals', [1:10]', ...
+  'yvals', randn(10, 1), ...
+  'dy', 0.1*ones(10, 1) ...
+  ));
+
+y = ln(x);
+
+% check that dy = abs(1./x) * dy
+if y.dy ~= abs(1./(x.y)) .* x.dy
+  test = false;
+end
+
+% Case 15: y = log10(x), with 
+% x a variable with uncertainty
+x = ao(plist(...
+  'xvals', [1:10]', ...
+  'yvals', randn(10, 1), ...
+  'dy', 0.1*ones(10, 1) ...
+  ));
+
+y = log10(x);
+
+% check that dy = abs(1./(x*log(10))) * dy
+if y.dy ~= abs(1./(x.y * log(10))) .* x.dy
+  test = false;
+end
+
+% Case 16: y = sin(x), with 
+% x a variable with uncertainty
+x = ao(plist(...
+  'xvals', [1:10]', ...
+  'yvals', randn(10, 1), ...
+  'dy', 0.1*ones(10, 1) ...
+  ));
+
+y = sin(x);
+
+% check that dy = abs(cos(x)) * dy
+if y.dy ~= abs(cos(x.y)) .* x.dy
+  test = false;
+end
+
+% Case 17: y = cos(x), with 
+% x a variable with uncertainty
+x = ao(plist(...
+  'xvals', [1:10]', ...
+  'yvals', randn(10, 1), ...
+  'dy', 0.1*ones(10, 1) ...
+  ));
+
+y = cos(x);
+
+% check that dy = abs(sin(x)) * dy
+if y.dy ~= abs(sin(x.y)) .* x.dy
+  test = false;
+end
+
+
+% Case 18: y = tan(x), with 
+% x a variable with uncertainty
+x = ao(plist(...
+  'xvals', [1:10]', ...
+  'yvals', randn(10, 1), ...
+  'dy', 0.1*ones(10, 1) ...
+  ));
+
+y = tan(x);
+
+% check that dy = abs(1./(cos(x)).^2) * dy
+if y.dy ~= abs(1./(cos(x.y)).^2) .* x.dy
+  test = false;
+end
+
+% Case 19: y = asin(x), with 
+% x a variable with uncertainty
+x = ao(plist(...
+  'xvals', [-1:0.1:1]', ...
+  'yvals', -1 + 2.*rand(21, 1), ...
+  'dy', 0.01*ones(21, 1) ...
+  ));
+
+y = asin(x);
+
+% check that dy = abs(1./(1 - x.^2).^(1/2)) * dy
+if y.dy ~= abs(1./(1 - x.y.^2).^(1/2)) .* x.dy
+  test = false;
+end
+
+% Case 20: y = acos(x), with 
+% x a variable with uncertainty
+x = ao(plist(...
+  'xvals', [-1:0.1:1]', ...
+  'yvals', -1 + 2.*rand(21, 1), ...
+  'dy', 0.01*ones(21, 1) ...
+  ));
+
+y = acos(x);
+
+% check that dy = abs(-1./(1 - x.^2).^(1/2)) * dy
+if y.dy ~= abs(-1./(1 - x.y.^2).^(1/2)) .* x.dy
+  test = false;
+end
+
+
+% Case 21: y = atan(x), with 
+% x a variable with uncertainty
+x = ao(plist(...
+  'xvals', [-1:0.1:1]', ...
+  'yvals', -1 + 2.*rand(21, 1), ...
+  'dy', 0.01*ones(21, 1) ...
+  ));
+
+y = atan(x);
+
+% check that dy = abs(1./(1 + x.^2)) * dy
+if y.dy ~= abs(1./(1 + x.y.^2)) .* x.dy
+  test = false;
+end
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