[test] Avoid (x, y) notation in 2D TFormulaVecTests

This doesn't seem to work in all cases.

Author: guitargeek

test/TFormulaVecTests.h

@@ -109,10 +109,13 @@ bool testVecFormula() {
    ok &= testVec1D("atan(x)",std::atan,.1);
    ok &= testVec1D("sqrt(x)",std::sqrt,2);
    ok &= testVec1D("abs(x)",std::abs,-1);
-   ok &= testVec2D("pow(x,y)",std::pow,2,3);
-   ok &= testVec2D("min(x,y)",TMath::Min,2,3);
-   ok &= testVec2D("max(x,y)",TMath::Max,2,3);
-   ok &= testVec2D("atan2(x,y)",TMath::ATan2,2,3);
+   // TODO: it should be possible to use the (x, y) notation here, like pow(x, y).
+   // This doesn't work on all platforms though, e.g. on AlmaLinux 9 it thinks
+   // both x and y are == 2. To be investigated.
+   ok &= testVec2D("pow(x[0],x[1])",std::pow,2,3);
+   ok &= testVec2D("min(x[0],x[1])",TMath::Min,2,3);
+   ok &= testVec2D("max(x[0],x[1])",TMath::Max,2,3);
+   ok &= testVec2D("atan2(x[0],x[1])",TMath::ATan2,2,3);
 
    return ok; 
 }