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diff scripts/statistics/distributions/poissinv.m @ 13171:19b9f17d22af

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Overhaul of statistical distribution functions Support class "single" 75% reduction in memory usage More Matlab compatibility for corner cases * betacdf.m, betainv.m, betapdf.m, betarnd.m, binocdf.m, binoinv.m, binopdf.m, binornd.m, cauchy_cdf.m, cauchy_inv.m, cauchy_pdf.m, cauchy_rnd.m, chi2cdf.m, chi2inv.m, chi2pdf.m, chi2rnd.m, discrete_cdf.m, discrete_inv.m, discrete_pdf.m, discrete_rnd.m, empirical_cdf.m, empirical_inv.m, empirical_pdf.m, empirical_rnd.m, expcdf.m, expinv.m, exppdf.m, exprnd.m, fcdf.m, finv.m, fpdf.m, frnd.m, gamcdf.m, gaminv.m, gampdf.m, gamrnd.m, geocdf.m, geoinv.m, geopdf.m, geornd.m, hygecdf.m, hygeinv.m, hygepdf.m, hygernd.m, kolmogorov_smirnov_cdf.m, laplace_cdf.m, laplace_inv.m, laplace_pdf.m, laplace_rnd.m, logistic_cdf.m, logistic_inv.m, logistic_pdf.m, logistic_rnd.m, logncdf.m, logninv.m, lognpdf.m, lognrnd.m, nbincdf.m, nbininv.m, nbinpdf.m, nbinrnd.m, normcdf.m, norminv.m, normpdf.m, normrnd.m, poisscdf.m, poissinv.m, poisspdf.m, poissrnd.m, stdnormal_cdf.m, stdnormal_inv.m, stdnormal_pdf.m, stdnormal_rnd.m, tcdf.m, tinv.m, tpdf.m, trnd.m, unidcdf.m, unidinv.m, unidpdf.m, unidrnd.m, unifcdf.m, unifinv.m, unifpdf.m, unifrnd.m, wblcdf.m, wblinv.m, wblpdf.m, wblrnd.m: Return "single" outputs for "single" inputs, Use logical indexing rather than find() for 75% memory savings, Add tests for all functions, Use consistent documentation across all functions, More Matlab compatibilitcy for corner cases.
author Rik <octave@nomad.inbox5.com>
date Tue, 20 Sep 2011 12:13:13 -0700
parents fd0a3ac60b0e
children 72c96de7a403
line wrap: on
line diff
--- a/scripts/statistics/distributions/poissinv.m	Tue Sep 20 11:41:59 2011 -0700
+++ b/scripts/statistics/distributions/poissinv.m	Tue Sep 20 12:13:13 2011 -0700
@@ -1,3 +1,4 @@
+## Copyright (C) 2011 Rik Wehbring
 ## Copyright (C) 1995-2011 Kurt Hornik
 ##
 ## This file is part of Octave.
@@ -18,7 +19,7 @@
 
 ## -*- texinfo -*-
 ## @deftypefn {Function File} {} poissinv (@var{x}, @var{lambda})
-## For each component of @var{x}, compute the quantile (the inverse of
+## For each element of @var{x}, compute the quantile (the inverse of
 ## the CDF) at @var{x} of the Poisson distribution with parameter
 ## @var{lambda}.
 ## @end deftypefn
@@ -35,42 +36,68 @@
   if (!isscalar (lambda))
     [retval, x, lambda] = common_size (x, lambda);
     if (retval > 0)
-      error ("poissinv: X and LAMBDA must be of common size or scalar");
+      error ("poissinv: X and LAMBDA must be of common size or scalars");
     endif
   endif
 
-  inv = zeros (size (x));
-
-  k = find ((x < 0) | (x > 1) | isnan (x) | !(lambda > 0));
-  if (any (k))
-    inv(k) = NaN;
+  if (iscomplex (x) || iscomplex (lambda))
+    error ("poissinv: X and LAMBDA must not be complex");
   endif
 
-  k = find ((x == 1) & (lambda > 0));
-  if (any (k))
-    inv(k) = Inf;
+  if (isa (x, "single") || isa (lambda, "single"))
+    inv = zeros (size (x), "single");
+  else
+    inv = zeros (size (x));
   endif
 
+  k = (x < 0) | (x > 1) | isnan (x) | !(lambda > 0);
+  inv(k) = NaN;
+
+  k = (x == 1) & (lambda > 0);
+  inv(k) = Inf;
+
   k = find ((x > 0) & (x < 1) & (lambda > 0));
-  if (any (k))
-    if (isscalar (lambda))
-      cdf = exp (-lambda) * ones (size (k));
+  if (isscalar (lambda))
+    cdf = exp (-lambda) * ones (size (k));
+  else
+    cdf = exp (-lambda(k));
+  endif
+  
+  while (1)
+    m = find (cdf < x(k));
+    if (any (m))
+      inv(k(m)) += 1;
+      if (isscalar (lambda))
+        cdf(m) = cdf(m) + poisspdf (inv(k(m)), lambda);
+      else
+        cdf(m) = cdf(m) + poisspdf (inv(k(m)), lambda(k(m)));
+      endif
     else
-      cdf = exp (-lambda(k));
+      break;
     endif
-    while (1)
-      m = find (cdf < x(k));
-      if (any (m))
-        inv(k(m)) = inv(k(m)) + 1;
-        if (isscalar (lambda))
-          cdf(m) = cdf(m) + poisspdf (inv(k(m)), lambda);
-        else
-          cdf(m) = cdf(m) + poisspdf (inv(k(m)), lambda(k(m)));
-        endif
-      else
-        break;
-      endif
-    endwhile
-  endif
+  endwhile
 
 endfunction
+
+
+%!shared x
+%! x = [-1 0 0.5 1 2];
+%!assert(poissinv (x, ones(1,5)), [NaN 0 1 Inf NaN]);
+%!assert(poissinv (x, 1), [NaN 0 1 Inf NaN]);
+%!assert(poissinv (x, [1 0 NaN 1 1]), [NaN NaN NaN Inf NaN]);
+%!assert(poissinv ([x(1:2) NaN x(4:5)], 1), [NaN 0 NaN Inf NaN]);
+
+%% Test class of input preserved
+%!assert(poissinv ([x, NaN], 1), [NaN 0 1 Inf NaN NaN]);
+%!assert(poissinv (single([x, NaN]), 1), single([NaN 0 1 Inf NaN NaN]));
+%!assert(poissinv ([x, NaN], single(1)), single([NaN 0 1 Inf NaN NaN]));
+
+%% Test input validation
+%!error poissinv ()
+%!error poissinv (1)
+%!error poissinv (1,2,3)
+%!error poissinv (ones(3),ones(2))
+%!error poissinv (ones(2),ones(3))
+%!error poissinv (i, 2)
+%!error poissinv (2, i)
+