TF1 vs TFormula parsing of "expo(0)"

ROOT
1

Hi,

It looks like a TF1 defined by TF1 F("","expo(0)+expo(2)",10,100) and TFormula F("","expo(0)+expo(2)") do not behave the same way. Oddly when initialized, the TF1 function has two parameters and evaluates to 8.389 (regardless of x-value) when these two parameters equal to zero, while the TFormula works just fine, evaluating to 2.

Originally, I ran into this because I incorrectly used expo(0) rather than expo in the TF1, but I find it surprising that TFormula operates validly with expo(0).

Now that I found my issue (expo vs expo(0)) this may be a moot discrepancy, but I think it illuminates an issue in relating TF1 to TFormula. I’d also like to know the best resource for TFormula's extent of features; the DOxygen entry is a little terse.

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ROOT Version: 6.18/01
Platform: linuxx8664gcc
Compiler: gcc 7.4.0-1ubuntu1~18.04.1

2

Try to: F.Print();

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