[hist] fix bug in SmoothArray

ferdymercury · dpiparo · commit d08f1d32d124 · 2025-03-23T06:23:22.000+01:00
introduced in this refactoring commit 9ef86d5#diff-f9554db4e8f6e87a454392c3387c28fb198444cea915e6365fac55317f9ea5f2R23-R6823 Found out by https://root-forum.cern.ch/t/useless-check-bug-in-th1-smooth/63183/3
diff --git a/hist/hist/src/TH1.cxx b/hist/hist/src/TH1.cxx
@@ -6855,7 +6855,7 @@ void  TH1::SmoothArray(Int_t nn, Double_t *xx, Int_t ntimes)
             const double tmp1 = zz[ii + 2] - zz[ii];
             if  (tmp0 * tmp1 <= 0) continue;
             int jk = 1;
-            if  ( std::abs(tmp0) > std::abs(tmp0) ) jk = -1;
+            if  ( std::abs(tmp0) > std::abs(tmp1) ) jk = -1;
             yy[ii] = -0.5*zz[ii - 2*jk] + zz[ii]/0.75 + zz[ii + 2*jk] /6.;
             yy[ii + jk] = 0.5*(zz[ii + 2*jk] - zz[ii - 2*jk]) + zz[ii];
          }

Original file line number	Diff line number	Diff line change
`@@ -6855,7 +6855,7 @@ void TH1::SmoothArray(Int_t nn, Double_t *xx, Int_t ntimes)`
`6855`	`6855`	`const double tmp1 = zz[ii + 2] - zz[ii];`
`6856`	`6856`	`if (tmp0 * tmp1 <= 0) continue;`
`6857`	`6857`	`int jk = 1;`
`6858`		`- if ( std::abs(tmp0) > std::abs(tmp0) ) jk = -1;`
	`6858`	`+ if ( std::abs(tmp0) > std::abs(tmp1) ) jk = -1;`
`6859`	`6859`	`yy[ii] = -0.5zz[ii - 2jk] + zz[ii]/0.75 + zz[ii + 2*jk] /6.;`
`6860`	`6860`	`yy[ii + jk] = 0.5(zz[ii + 2jk] - zz[ii - 2*jk]) + zz[ii];`
`6861`	`6861`	`}`