# [Ecm-commits] r2646 - trunk

cvs commits ecm-commits at lists.gforge.inria.fr
Fri Feb 27 16:32:48 CET 2015

```Author: zimmerma
Date: 2015-02-27 16:32:48 +0100 (Fri, 27 Feb 2015)
New Revision: 2646

Modified:
trunk/torsions.c
Log:
fixed typos

Modified: trunk/torsions.c
===================================================================
--- trunk/torsions.c	2015-02-27 14:41:46 UTC (rev 2645)
+++ trunk/torsions.c	2015-02-27 15:32:48 UTC (rev 2646)
@@ -19,7 +19,7 @@

#define DEBUG_TORSION 0

-/* We use three variants of Weiestrass parametrization:
+/* We use three variants of Weierstrass parametrization:
CW (complete): y^2+a1*x*y+a3*y=x^3+a2*x^2+a4*x+a6
MW (medium)  : y^2=x^3+a2*x^2+a4*x+a6
SW (short)   : y^2=x^3+a4*x+a6
@@ -87,7 +87,7 @@
/********** conversion between Weierstass forms **********/

/* From a curve in long form y^2+a1*x*y+a3*y = x^3+a2*x^2+a4*x+a6
-   to a medium Weiestrass form Y^2 = X^3 + A2 * X^2 + A4 * X + A6
+   to a medium Weierstrass form Y^2 = X^3 + A2 * X^2 + A4 * X + A6
where X = x, Y = y+(a1*X+a3)/2
A2 = 1/4*a1^2+a2
A4 = 1/2*a1*a3+a4
@@ -234,7 +234,7 @@
}

/* From a curve in Kubert form Y^2+(1-c)*X*Y-b*Y = X^3-b*X^2
-   to a Weiestrass form y^2 = X^3 + a2 * X^2 + a4 * X + a6
+   to a Weierstrass form y^2 = X^3 + a2 * X^2 + a4 * X + a6
where y = Y+((1-c)*X-b)/2
WE:=[0,(1/4*c^2+1/4-1/2*c-b),0,(1/2*c*b-1/2*b),1/4*b^2]);
We compute:

```