Gauss运行一般脉冲响应函数，代码总出错，求指点...-经管之家官网！

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GIRFS:
begwind;
window(2,2,0);
_plegctl = 1;
_plegstr = "POS\000NEG\000SYM";
period = seqa(0,1,nsteps);
setwind(1);
title("dY to dM");
argh = md_idym~(-md_idymm)~mn_idymr~zeros(4+nsteps,1);
xy(period,argh[5:rows(argh),.]);
nextwind;
title("dP to dM");
argh = md_idpm~(-md_idpmm)~mn_idpmr~zeros(4+nsteps,1);
xy(period,argh[5:rows(argh),.]);
nextwind;
title("Y to dM");
argh = md_iym~(-md_iymm)~mn_iymr~zeros(4+nsteps,1);
xy(period,argh[5:rows(argh),.]);
nextwind;
title("P to dM");
argh = md_ipm~(-md_ipmm)~mn_ipmr~zeros(4+nsteps,1);
xy(period,argh[5:rows(argh),.]);
endwind;
return;
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参考着别人的代码在自己边改边做...
用对方元数据运行的时候老是会显示这一段出错...
错误栏是：
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Undefined symbols:
begwind D:\IRFS.GSS(872)
window D:\IRFS.GSS(875)
setwind D:\IRFS.GSS(879)
title D:\IRFS.GSS(880)
xy D:\IRFS.GSS(882)
nextwind D:\IRFS.GSS(883)
endwind D:\IRFS.GSS(895)
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这是什么原因呢？求高手指点！