$G_\pi(Q^2)$ & .9825(24) & .9609(43) & .8834(120) & .8780(134) & .8511(188) & .7313(186) & .5875(200)\
\
\
$Q^2$(GeV$^2$) & 0.01842 & 0.04237 & 0.1132 & 0.1223 & 0.1623 & 0.3651 & 0.7302\
$G_\pi(Q^2)$ & .9836(37) & .9604(61) & .8816(154) & .8746(160) & .8400(184) & .6934(212) & .5191(189)\
\
\
$Q^2$(GeV$^2$) & 0.01841 & 0.04237 & 0.1062 & 0.1143 & 0.1495 & 0.3651 & 0.7302\
$G_\pi(Q^2)$ & .9730(54) & .9428(66) & .9036(315) & .8920(319) & .8805(476) & .5999(535) & .4706(574)\
\
\
$Q^2$(GeV$^2$) & 0.01842 & 0.04237 & 0.09612 & 0.1030 & 0.1324 & 0.3651 & 0.7302\
$G_\pi(Q^2)$ & .9728(44) & .9372(72) & .8624(310) & .8456(343) & .7929(452) & .9758(3376) & .6115(1943)\

We observe in Table \[table:PFF\_dataset1\] for data set I that the error for the form factor becomes large toward small pion mass and large momentum transfer. In order to improve the quality of data, we repeat the measurements (i) choosing the incoming and outgoing pions to have momenta with the same magnitude $|\vec{p'}|=|\vec{p}|$, and (ii) applying 4 random $Z(2) \otimes Z(2)$ wall sources located at $t=0,16,32,48$ for the lattice time extent of 64. The twist technique is applied to two quarks running from the source to the current and 