doc/master/pyroot001__arrayInterface_8py.html

import ROOT

from sys import exit


try:

    import numpy as np

except:

    exit()


# Create a vector ROOT object and assign values

# Note that this works as well with a TVec

vec = ROOT.std.vector("float")(2)

vec[0] = 1

vec[1] = 2

print("Content of the ROOT vector object: {}".format([x for x in vec]))


# Interface ROOT vector with a numpy array

array = np.asarray(vec)

print("Content of the associated numpy array: {}".format([x for x in array]))


# The numpy array adopts the memory of the vector without copying the content.

# Note that the first entry of the numpy array changes when assigning a new

# value to the first entry of the ROOT vector.

vec[0] = 42

print(

    "Content of the numpy array after changing the first entry of the ROOT vector: {}".

    format([x for x in array]))


# Use numpy features on data of ROOT objects

print("Mean of the numpy array entries: {}".format(np.mean(array)))

format
Option_t Option_t TPoint TPoint const char GetTextMagnitude GetFillStyle GetLineColor GetLineWidth GetMarkerStyle GetTextAlign GetTextColor GetTextSize void char Point_t Rectangle_t WindowAttributes_t Float_t Float_t Float_t Int_t Int_t UInt_t UInt_t Rectangle_t Int_t Int_t Window_t TString Int_t GCValues_t GetPrimarySelectionOwner GetDisplay GetScreen GetColormap GetNativeEvent const char const char dpyName wid window const char font_name cursor keysym reg const char only_if_exist regb h Point_t winding char text const char depth char const char Int_t count const char ColorStruct_t color const char Pixmap_t Pixmap_t PictureAttributes_t attr const char char ret_data h unsigned char height h Atom_t Int_t ULong_t ULong_t unsigned char prop_list Atom_t Atom_t Atom_t Time_t format
Definition TGWin32VirtualXProxy.cxx:249