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Function "atan": Cosmetic changes + "final" keyword. 

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/math/trunk@1242346 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Gilles Sadowski 2012-02-09 14:54:00 +00:00
parent 5c72fa771e
commit 1513e3db5f
1 changed files with 12 additions and 15 deletions
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27
src/main/java/org/apache/commons/math/util/FastMath.java
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@ -2454,11 +2454,11 @@ public class FastMath {
}
/* Estimate the closest tabulated arctan value, compute eps = xa-tangentTable */
if (xa < 1.0) {
if (xa < 1) {
idx = (int) (((-1.7168146928204136 * xa * xa + 8.0) * xa) + 0.5);
} else {
double temp = 1.0/xa;
idx = (int) (-((-1.7168146928204136 * temp * temp + 8.0) * temp) + 13.07);
final double oneOverXa = 1 / xa;
idx = (int) (-((-1.7168146928204136 * oneOverXa * oneOverXa + 8.0) * oneOverXa) + 13.07);
}
double epsA = xa - TANGENT_TABLE_A[idx];
double epsB = -(epsA - xa + TANGENT_TABLE_A[idx]);
@ -2479,14 +2479,14 @@ public class FastMath {
if (idx == 0) {
/* If the slope of the arctan is gentle enough (< 0.45), this approximation will suffice */
//double denom = 1.0 / (1.0 + xa*tangentTableA[idx] + xb*tangentTableA[idx] + xa*tangentTableB[idx] + xb*tangentTableB[idx]);
double denom = 1.0 / (1.0 + (xa + xb) * (TANGENT_TABLE_A[idx] + TANGENT_TABLE_B[idx]));
final double denom = 1d / (1d + (xa + xb) * (TANGENT_TABLE_A[idx] + TANGENT_TABLE_B[idx]));
//double denom = 1.0 / (1.0 + xa*tangentTableA[idx]);
ya = epsA * denom;
yb = epsB * denom;
} else {
double temp2 = xa * TANGENT_TABLE_A[idx];
double za = 1.0 + temp2;
double zb = -(za - 1.0 - temp2);
double za = 1d + temp2;
double zb = -(za - 1d - temp2);
temp2 = xb * TANGENT_TABLE_A[idx] + xa * TANGENT_TABLE_B[idx];
temp = za + temp2;
zb += -(temp - za - temp2);
@ -2515,7 +2515,7 @@ public class FastMath {
epsB = yb;
/* Evaluate polynomial */
double epsA2 = epsA*epsA;
final double epsA2 = epsA * epsA;
/*
yb = -0.09001346640161823;
@ -2542,10 +2542,7 @@ public class FastMath {
ya = temp;
/* Add in effect of epsB. atan'(x) = 1/(1+x^2) */
yb += epsB / (1.0 + epsA * epsA);
double result;
double resultb;
yb += epsB / (1d + epsA * epsA);
//result = yb + eighths[idx] + ya;
double za = EIGHTHS[idx] + ya;
@ -2554,13 +2551,13 @@ public class FastMath {
zb += -(temp - za - yb);
za = temp;
result = za + zb;
resultb = -(result - za - zb);
double result = za + zb;
double resultb = -(result - za - zb);
if (leftPlane) {
// Result is in the left plane
final double pia = 1.5707963267948966*2.0;
final double pib = 6.123233995736766E-17*2.0;
final double pia = 1.5707963267948966 * 2;
final double pib = 6.123233995736766E-17 * 2;
za = pia - result;
zb = -(za - pia + result);