formula1.py

## \ingroup tutorial_graphics

## \notebook -js

## TF1 example.

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## \macro_image

## \macro_code

##

## \author Wim Lavrijsen

from ROOT import TCanvas, TFormula, TF1

from ROOT import gROOT, gObjectTable

c1 = TCanvas( 'c1', 'Example with Formula', 200, 10, 700, 500 )

# We create a formula object and compute the value of this formula

# for two different values of the x variable.

form1 = TFormula( 'form1', 'sqrt(abs(x))' )

form1.Eval( 2 )

form1.Eval( -45 )

# Create a one dimensional function and draw it

fun1 = TF1( 'fun1', 'abs(sin(x)/x)', 0, 10 )

c1.SetGridx()

c1.SetGridy()

fun1.Draw()

c1.Update()

# Before leaving this demo, we print the list of objects known to ROOT

#

if ( gObjectTable ):

gObjectTable.Print()