為何跑不出任何股票？

寫了一個以下的選股腳本,頻率:季,為怕跑不出股票,篩選條件刻意設為數值不等於0,但是依然跑不出任何股票,煩請協助看看問題出在哪裡？

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var: MTA(0),NIMTA(0), NIMTAAVG(0), TLMTA(0), CASHMTA(0), EXRET(0), EXRETAVG(0), SIGMA(0), RSIZE(0), MB(0), PRICE(0), LPFD(0), PFD(0), stockreturn(0), TSEreturn(0);

value1=GetField("稅前息前淨利","Q");

value2=GetSymbolField("TSE.TW","收盤價","Q");

value3=GetField("收盤價","Q");

value4=GetField("收盤價","D");

TSEreturn = (value2-value2[1])/value2[1];

stockreturn= (value3-value3[1])/value3[1];

MTA=GetField("總市值(億)","Q")*100+GetField("負債總額","Q");

NIMTA = GetField("稅前息前淨利","Q") / MTA;

NIMTAAVG = 0.5333*NIMTA+0.2666*NIMTA[1]+0.1333*NIMTA[2]+0.0666*NIMTA[3];

EXRET = (log(1+stockreturn)-log(1+TSEreturn)) / 2;

EXRETAVG = 0.5333*EXRET+0.2666*EXRET[1]+0.1333*EXRET[2]+0.0666*EXRET[3];

RSIZE = log(GetField("總市值","Q")/GetSymbolField("TSE.TW","總市值","Q"));

TLMTA = GetField("負債總額","Q") / MTA;

CASHMTA = GetField("現金及約當現金","Q") / MTA;

SIGMA = StandardDev(value4,60,2);

MB = MTA / (GetField("資產總額","Q")+0.1*(GetField("總市值(億)","Q")*100-GetField("資產總額","Q")));

//PRICE = log(value4);

if value4 >15 then PRICE = log(15)

else PRICE = log(value4) ;

LPFD = -20.26*NIMTAAVG + 1.42*TLMTA - 7.13*EXRETAVG + 1.41*SIGMA - 0.045*RSIZE - 2.13*CASHMTA + 0.075*MB - 0.058*PRICE - 9.16;

PFD = 1/(1+ExpValue(-LPFD));

if PFD<>0

then ret=1;

setoutputname1("PFD");

outputfield1(PFD);