v0.3.1.0 started

CHANGELOG.md

@@ -216,4 +216,10 @@ spray with some values. This is the same as `evalSpraySpray`(which will
 probably disappear in the future).
 
 * Function `evalParametricSpray` to replace the variables of a parametric 
-spray with some values.
+spray with some values.
+
+
+## 0.3.1.0 - 2024-XX-XX
+
+* Slight improvement of the `jacobiPolynomial` function.
+

hspray.cabal

@@ -1,5 +1,5 @@
 name:                hspray
-version:             0.3.0.0
+version:             0.3.1.0
 synopsis:            Multivariate polynomials and fractions of multivariate polynomials.
 description:         Manipulation of multivariate polynomials over a commutative ring and fractions of multivariate polynomials over a commutative field, Gröbner bases, resultant and subresultants, and greatest common divisor. It is possible to deal with multivariate polynomials whose coefficients are fractions of multivariate polynomials, and they can be interpreted as parametric polynomials with symbolic parameters.
 homepage:            https://github.com/stla/hspray#readme

src/Math/Algebra/Hspray.hs

@@ -3117,13 +3117,22 @@ jacobiPolynomial n
     a0 = n0 ^+^ alpha0
     b0 = n0 ^+^ beta0
     c0 = a0 ^+^ b0
-    divisor = 2.^(n0^*^(c0 ^-^ n0)^*^(c0 ^-^ cst 2))
-    simpleSpray = (c0 ^-^ cst 1) AlgMod.*> (
-        (c0^*^(c0 ^-^ cst 2)) *^ x ^+^ 
-          constantSpray ((alpha0 ^-^ beta0)^*^(alpha0 ^+^ beta0))
-      )
-    spray = HM.map (`RatioOfSprays` divisor) simpleSpray
-    rOS = RatioOfSprays (2.^((a0 ^-^ cst 1)^*^(b0 ^-^ cst 1)^*^c0)) divisor
+    c0' = c0 ^-^ cst 1
+    c0'' = c0 ^-^ cst 2
+    divisor = n0^*^(c0 ^-^ n0)^*^c0''
+    divisor' = 2 .^ divisor
+    divide = (`RatioOfSprays` divisor')
+    spray = HM.fromList [
+        (
+          Powers S.empty 0
+        , divide $ c0'^*^(alpha0 ^-^ beta0)^*^(alpha0 ^+^ beta0)
+        ),
+        (
+          Powers (S.singleton 1) 1
+        , divide $ c0' ^*^ c0 ^*^ c0''
+        )
+      ]
+    rOS = RatioOfSprays ((a0 ^-^ cst 1)^*^(b0 ^-^ cst 1)^*^c0) divisor
 
 -- | Pretty form of a parametric rational spray, using some given strings (typically some 
 -- letters) to denote the parameters and some given strings (typically some letters) to