X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=legendre_p_tilde.m;fp=legendre_p_tilde.m;h=e5e6f63b39b929731c3c8281f59b4510fbbf494c;hb=ee06b882dfb9a86788d7057cec8ca6d7680c5ca5;hp=0000000000000000000000000000000000000000;hpb=2fbcf94908d646ec62d2f15f7ec35288c6ac1cfe;p=octave.git

diff --git a/legendre_p_tilde.m b/legendre_p_tilde.m
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+++ b/legendre_p_tilde.m
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+function P_tilde = legendre_p_tilde(n, a, b)
+  ## Return the nth Legendre polynomial scaled to the interval [a,b].
+  ##
+  ## INPUTS:
+  ##
+  ##   * ``n`` - The index of the polynomial that we want.
+  ##
+  ##   * ``a`` - The left endpoint of the interval.
+  ##
+  ##   * ``b`` - The right endpoint of the interval.
+  ##
+  ## OUTPUTS:
+  ##
+  ##   * ``P_tilde`` - A polynomial function of one argument.
+  ##
+  if (n < 0)
+    ## Can't do anything here. Return nothing.
+    P = NA;
+  else
+    ## Compute the Legendre polynomial over [-1,1] and mangle it.
+    P = legendre_p(n)
+    P_tilde = @(x) P( (2/(b-a))*x + 1 - (2*b)/(b-a) )
+  end
+end